Toshiba RPTV 50H72 - blue screen only

[bharat]

This TV only shows blue screen. When I go into setup, I can see that
red and green CRTs are working (I see green and red colors) but the
screen background stays blue. When I connect a DVD player, the screen
briefly shows real picture but then turns completely blue. Ditto when
I turn the TV off with DVD running (picture shows for an instant
before TV turns OFF). I think video apms that drive yokes are
suspect..but wanted to confirm with someone before I order the ICs and
replace them. I checked all power supplies and they are OK (specially
to the video amp ICs). All components I checked seem fine (atleast
the ones I checked showed appropriate behavior). Any suggestions are
appreciated.

bharat

 

[Jerry G.]

There may be a loss of sync to the scan circuits, or there may be a response
problem in the video path, thus not allowing proper sync. You would have to
get the service manual, and trace through with a scope to see where this
type of fault is. Also, checking for the proper supply voltages in the
various stages would be a proper thing to do.

If you are not trained and equipped in TV service, I would suggest to have
the set properly looked after.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"bharat" <bhuva@vuse.vanderbilt.edu> wrote in message
news:27bb423c.0405011308.78af06f5@posting.google.com...
This TV only shows blue screen. When I go into setup, I can see that
red and green CRTs are working (I see green and red colors) but the
screen background stays blue. When I connect a DVD player, the screen
briefly shows real picture but then turns completely blue. Ditto when
I turn the TV off with DVD running (picture shows for an instant
before TV turns OFF). I think video apms that drive yokes are
suspect..but wanted to confirm with someone before I order the ICs and
replace them. I checked all power supplies and they are OK (specially
to the video amp ICs). All components I checked seem fine (atleast
the ones I checked showed appropriate behavior). Any suggestions are
appreciated.

bharat

 

[David]

Ditto on the find someone who knows what they are doing.

This statement (typo fixed) clearly indicates a total lack of understanding
of what is going on inside the set:
" I think video amps that drive yokes are suspect."

David



"Jerry G." <jerryg50@hotmail.com> wrote in message
news:c71lf1$rig$1@news.eusc.inter.net...

There may be a loss of sync to the scan circuits, or there may be a
response
problem in the video path, thus not allowing proper sync. You would have
to
get the service manual, and trace through with a scope to see where this
type of fault is. Also, checking for the proper supply voltages in the
various stages would be a proper thing to do.

If you are not trained and equipped in TV service, I would suggest to have
the set properly looked after.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"bharat" <bhuva@vuse.vanderbilt.edu> wrote in message
news:27bb423c.0405011308.78af06f5@posting.google.com...
This TV only shows blue screen. When I go into setup, I can see that
red and green CRTs are working (I see green and red colors) but the
screen background stays blue. When I connect a DVD player, the screen
briefly shows real picture but then turns completely blue. Ditto when
I turn the TV off with DVD running (picture shows for an instant
before TV turns OFF). I think video apms that drive yokes are
suspect..but wanted to confirm with someone before I order the ICs and
replace them. I checked all power supplies and they are OK (specially
to the video amp ICs). All components I checked seem fine (atleast
the ones I checked showed appropriate behavior). Any suggestions are
appreciated.

bharat

 

[bharat]

"David" <dkuhajda@locl.net.spam> wrote in message news:<40947c4f@news.greennet.net>...

Ditto on the find someone who knows what they are doing.

This statement (typo fixed) clearly indicates a total lack of understanding
of what is going on inside the set:
" I think video amps that drive yokes are suspect."

This newsgroup is for help. If you cannot provide any help, please
stay off the line. If I knew what was wrong, I would not have posted
the article in the first place. There was a post previously in this
newsgroup where the person was seeing all green screen...the hints
were for checking the video amps. So I assumed that would be a first
place to start.

Your typo-corrected sentence is same as mine. May be you should get
some education before getting on the net, you !@#$%^! Send me your
email address and we can take this discussion about your intelligence
and mine off the newsgroup.

bharat

 

[David]

So what is an apms?
It still is clear in your posting that you have no clue how a tv set or rptv
works.

We just went through court because someone idiot bought a part from us (we
looked up the part number at his request) and the idiot wound up catching
the tv and house on fire!!!!! So he tried to sue us!!!

So don't go telling me that you think you know what you are doing when it is
clear in your post that you do not. Assuming what you said was video amps,
video amps do not drive yokes, period.


"bharat" <bhuva@vuse.vanderbilt.edu> wrote in message
news:27bb423c.0405020839.6f9ea779@posting.google.com...

"David" <dkuhajda@locl.net.spam> wrote in message
news:<40947c4f@news.greennet.net>...
Ditto on the find someone who knows what they are doing.

This statement (typo fixed) clearly indicates a total lack of
understanding
of what is going on inside the set:
" I think video amps that drive yokes are suspect."


This newsgroup is for help. If you cannot provide any help, please
stay off the line. If I knew what was wrong, I would not have posted
the article in the first place. There was a post previously in this
newsgroup where the person was seeing all green screen...the hints
were for checking the video amps. So I assumed that would be a first
place to start.

Your typo-corrected sentence is same as mine. May be you should get
some education before getting on the net, you !@#$%^! Send me your
email address and we can take this discussion about your intelligence
and mine off the newsgroup.

bharat

 

[Art]

Get the flippin set to a Qualified Service Company or consider replacing it
with a new one. It is perfectly obvious that you do not have the
qualifications to be attempting to service this product competently. Do
yourself a BIG Favor and have it done by the folk who do know how to do it
efficiently and safely.
"bharat" <bhuva@vuse.vanderbilt.edu> wrote in message
news:27bb423c.0405011308.78af06f5@posting.google.com...

This TV only shows blue screen. When I go into setup, I can see that
red and green CRTs are working (I see green and red colors) but the
screen background stays blue. When I connect a DVD player, the screen
briefly shows real picture but then turns completely blue. Ditto when
I turn the TV off with DVD running (picture shows for an instant
before TV turns OFF). I think video apms that drive yokes are
suspect..but wanted to confirm with someone before I order the ICs and
replace them. I checked all power supplies and they are OK (specially
to the video amp ICs). All components I checked seem fine (atleast
the ones I checked showed appropriate behavior). Any suggestions are
appreciated.

bharat

 

[Alan Harriman]

On Sun, 2 May 2004 15:16:46 -0400, "Art" <stubby@comcast.net> wrote:

Get the flippin set to a Qualified Service Company or consider replacing it
with a new one. It is perfectly obvious that you do not have the
qualifications to be attempting to service this product competently. Do
yourself a BIG Favor and have it done by the folk who do know how to do it
efficiently and safely.

Agreed. Pay a little now, or a lot later. That's an excellent TV - it's worth a
couple bucks to get it repaired.

Alan Harriman

"bharat" <bhuva@vuse.vanderbilt.edu> wrote in message
news:27bb423c.0405011308.78af06f5@posting.google.com...
This TV only shows blue screen. When I go into setup, I can see that
red and green CRTs are working (I see green and red colors) but the
screen background stays blue. When I connect a DVD player, the screen
briefly shows real picture but then turns completely blue. Ditto when
I turn the TV off with DVD running (picture shows for an instant
before TV turns OFF). I think video apms that drive yokes are
suspect..but wanted to confirm with someone before I order the ICs and
replace them. I checked all power supplies and they are OK (specially
to the video amp ICs). All components I checked seem fine (atleast
the ones I checked showed appropriate behavior). Any suggestions are
appreciated.

bharat

 

[Eugen T]

Wow, I have never seen so many arrogant people in one newsgroup at the same
time.
If you can't help, then just don't say anything.

"Art" <stubby@comcast.net> wrote in message
news:AIednZZOsuy41AjdRVn-sA@comcast.com...

Get the flippin set to a Qualified Service Company or consider replacing
it
with a new one. It is perfectly obvious that you do not have the
qualifications to be attempting to service this product competently. Do
yourself a BIG Favor and have it done by the folk who do know how to do it
efficiently and safely.
"bharat" <bhuva@vuse.vanderbilt.edu> wrote in message
news:27bb423c.0405011308.78af06f5@posting.google.com...
This TV only shows blue screen. When I go into setup, I can see that
red and green CRTs are working (I see green and red colors) but the
screen background stays blue. When I connect a DVD player, the screen
briefly shows real picture but then turns completely blue. Ditto when
I turn the TV off with DVD running (picture shows for an instant
before TV turns OFF). I think video apms that drive yokes are
suspect..but wanted to confirm with someone before I order the ICs and
replace them. I checked all power supplies and they are OK (specially
to the video amp ICs). All components I checked seem fine (atleast
the ones I checked showed appropriate behavior). Any suggestions are
appreciated.

bharat

 

[David]

We are helping him. If someone clearly has no clue what is going on, they
are probably going to do one of two things when they attempt to repair
something as complex as a tv set: 1. damage it beyond reasonable and
practical repair when they finally take it into someone qualified. or 2.
Get into something they shouldn't have and cause some potentially lethal or
serious injury to themselves.


"Eugen T" <viperz@nomorespam.com> wrote in message
news:BZflc.6845$ZJ5.339911@news20.bellglobal.com...

Wow, I have never seen so many arrogant people in one newsgroup at the
same
time.
If you can't help, then just don't say anything.

"Art" <stubby@comcast.net> wrote in message
news:AIednZZOsuy41AjdRVn-sA@comcast.com...
Get the flippin set to a Qualified Service Company or consider replacing
it
with a new one. It is perfectly obvious that you do not have the
qualifications to be attempting to service this product competently. Do
yourself a BIG Favor and have it done by the folk who do know how to do
it
efficiently and safely.
"bharat" <bhuva@vuse.vanderbilt.edu> wrote in message
news:27bb423c.0405011308.78af06f5@posting.google.com...
This TV only shows blue screen. When I go into setup, I can see that
red and green CRTs are working (I see green and red colors) but the
screen background stays blue. When I connect a DVD player, the screen
briefly shows real picture but then turns completely blue. Ditto when
I turn the TV off with DVD running (picture shows for an instant
before TV turns OFF). I think video apms that drive yokes are
suspect..but wanted to confirm with someone before I order the ICs and
replace them. I checked all power supplies and they are OK (specially
to the video amp ICs). All components I checked seem fine (atleast
the ones I checked showed appropriate behavior). Any suggestions are
appreciated.

bharat

 

[bharat]

Let me make a few things clear to answer your !@#$%^&*() arrogance.

Video amps are video amplifiers located in Q751 and Q752 on the signal
board. They drive yokes directly. In case any of you arrogant morons
had time and knowledge to understand what a schmatic looks like, you
would clearly see where video amplifiers are located. In adition,
amps is shorthand for amplifiers - any person knowledgable in
Electrical Engineering knows that. Next time, try to understand the
posting before replying. Your assumption that if you do not
understand something then it must be wrong is stupid!

Secondly, a while back in this newsgroup, there was a posting where
someone had green screen problem similar to mine. The solution posted
on the net was that the power supply to video amplifiers was suspect.
Hence my intuition regarding video amps (oops, I mean video amplifiers
for you intellectually-challenged guys).

Many of us know and understand the danger in repairing a TV set - not
just you arrogant !@$$%&*.

By the way, I have a PhD in electrical engineering and probably can
run circles around you when it comes to knowledge of electrical
engineering. However, I do not know specifically how to fix a TV and
hence the posting. If I had the time, I can understand the circuit
and then figure out what is wrong. I was hoping that this newsgroup,
with its collective knowledge, will help me fix this. Your arrogant
replies regarding "what is amps" itself shows that you do not have a
clue as to what an "amplifier" is. Take a few educational courses (or
read a book) before you start yelling at people.

Again, this newsgroup is for help. If you can help, please by all
means do so. If you do not understand what an "amps" is, do everyone
a favor and stop wasting bandwidth.

By the way, I am going to check the sync signals (for you stupids, it
is synchronization signals) to see if the problem lies there as
pointed out by more considerate members of this newsgroup. I thank
them.

bharat

 

[David]

Video amps are video amplifiers located in Q751 and Q752 on the signal
board. They drive yokes directly.

Video amplifiers do not drive yokes. Deflection circuitry drives deflection yokes. I have a PhD in electrical enginnering also, but not the attitude you have.

David

 

[Ken Weitzel]

David wrote:

Video amps are video amplifiers located in Q751 and Q752 on the signal
board. They drive yokes directly.


Video amplifiers do not drive yokes. Deflection circuitry drives deflection yokes. I have a PhD in electrical enginnering also, but not the attitude you have.

David

Hi...

Darn, you guys are embarassing me. I only got to
bachelor, and that only by the skin of my teeth.
(Hey, someone had to finish at the bottom of the class,
right?

Now old, long retired, and a stroke victim. Spent a
year couldn't walk, and a few years wondering who I
was and why.

I continue to get better, though, and can help a
little here. I agree that it's a problem with
the synchronization of his yokes. I suspect that
his blue yoke has gone out of sync, and he's going
to have to replace it.

A quick test to verify this would be to temporarily
switch the red and blue yoke (or the green and blue
yoke) just to see if it improves.

If it does, just call Toshiba or one of it's dealers
and order a new blue yoke.

Ken

 

[Leonard G. Caillouet]

David is completely correct, video amps don't drive yokes. I suppose they
didn't teach you that in electrical engineering.

Actually, Q751 and Q752 are convergence amplifiers, not video amplifiers,
and are likely not your problem. If one of these failed you would see
convergence problems, the set would shut down, or it would blow fuse(s) and
shut down. If you are getting a blue screen it is likely that you have lost
signal and the set is muting the video. Your problem could be anything
from not knowing how to operate the set to a problem anywhere in the signal
path.

If you are looking for video amplifiers you are looking in the wrong area.
You might want to check your assumptions and your reading of the schematic
before losing it on a forum where you are asking for help. Your post
indicated exactly what David noted, that you may be in over your head.

Now, if you want some help, why not tell us what equipment you have, and
what measurements you have taken and the signal conditions under which they
were taken. A few of us arrogant morons, as you put it, have quite a lot of
experience that we might be willing to share. Understand, however, that if
you don't have the right equipment, knowledge, and troubleshooting skills,
this may not be a realistic repair for you to attempt.

Your attitude and your PhD will not necessarily help in fixing your set. A
scope, some humility, and some TV service skills would go a lot farther.

Leonard
Pedantic asshole, maybe...arrogant moron, not usually


"bharat" <bhuva@vuse.vanderbilt.edu> wrote in message
news:27bb423c.0405031126.3a9ffb8d@posting.google.com...

Let me make a few things clear to answer your !@#$%^&*() arrogance.

Video amps are video amplifiers located in Q751 and Q752 on the signal
board. They drive yokes directly. In case any of you arrogant morons
had time and knowledge to understand what a schmatic looks like, you
would clearly see where video amplifiers are located. In adition,
amps is shorthand for amplifiers - any person knowledgable in
Electrical Engineering knows that. Next time, try to understand the
posting before replying. Your assumption that if you do not
understand something then it must be wrong is stupid!

Secondly, a while back in this newsgroup, there was a posting where
someone had green screen problem similar to mine. The solution posted
on the net was that the power supply to video amplifiers was suspect.
Hence my intuition regarding video amps (oops, I mean video amplifiers
for you intellectually-challenged guys).

Many of us know and understand the danger in repairing a TV set - not
just you arrogant !@$$%&*.

By the way, I have a PhD in electrical engineering and probably can
run circles around you when it comes to knowledge of electrical
engineering. However, I do not know specifically how to fix a TV and
hence the posting. If I had the time, I can understand the circuit
and then figure out what is wrong. I was hoping that this newsgroup,
with its collective knowledge, will help me fix this. Your arrogant
replies regarding "what is amps" itself shows that you do not have a
clue as to what an "amplifier" is. Take a few educational courses (or
read a book) before you start yelling at people.

Again, this newsgroup is for help. If you can help, please by all
means do so. If you do not understand what an "amps" is, do everyone
a favor and stop wasting bandwidth.

By the way, I am going to check the sync signals (for you stupids, it
is synchronization signals) to see if the problem lies there as
pointed out by more considerate members of this newsgroup. I thank
them.

bharat

 

[Art]

Absolute WASTE OF MY TIME!!! This flippin bloke is helpless, ignorant,
stupid and don't even realize it. Blantely obvious he does not want
assistance since he bloody knows everything about this device. Cheere,
Mate, have a good live as and Electrical Engineer. I hope I never encounter
any device you had any interest in designing or implimenting.
"Leonard G. Caillouet" <lcaillo_ns_@devoynet.com> wrote in message
news:Xnylc.64982$oN1.49963@bignews5.bellsouth.net...

David is completely correct, video amps don't drive yokes. I suppose they
didn't teach you that in electrical engineering.

Actually, Q751 and Q752 are convergence amplifiers, not video amplifiers,
and are likely not your problem. If one of these failed you would see
convergence problems, the set would shut down, or it would blow fuse(s)
and
shut down. If you are getting a blue screen it is likely that you have
lost
signal and the set is muting the video. Your problem could be anything
from not knowing how to operate the set to a problem anywhere in the
signal
path.

If you are looking for video amplifiers you are looking in the wrong area.
You might want to check your assumptions and your reading of the schematic
before losing it on a forum where you are asking for help. Your post
indicated exactly what David noted, that you may be in over your head.

Now, if you want some help, why not tell us what equipment you have, and
what measurements you have taken and the signal conditions under which
they
were taken. A few of us arrogant morons, as you put it, have quite a lot
of
experience that we might be willing to share. Understand, however, that
if
you don't have the right equipment, knowledge, and troubleshooting skills,
this may not be a realistic repair for you to attempt.

Your attitude and your PhD will not necessarily help in fixing your set.
A
scope, some humility, and some TV service skills would go a lot farther.

Leonard
Pedantic asshole, maybe...arrogant moron, not usually


"bharat" <bhuva@vuse.vanderbilt.edu> wrote in message
news:27bb423c.0405031126.3a9ffb8d@posting.google.com...
Let me make a few things clear to answer your !@#$%^&*() arrogance.

Video amps are video amplifiers located in Q751 and Q752 on the signal
board. They drive yokes directly. In case any of you arrogant morons
had time and knowledge to understand what a schmatic looks like, you
would clearly see where video amplifiers are located. In adition,
amps is shorthand for amplifiers - any person knowledgable in
Electrical Engineering knows that. Next time, try to understand the
posting before replying. Your assumption that if you do not
understand something then it must be wrong is stupid!

Secondly, a while back in this newsgroup, there was a posting where
someone had green screen problem similar to mine. The solution posted
on the net was that the power supply to video amplifiers was suspect.
Hence my intuition regarding video amps (oops, I mean video amplifiers
for you intellectually-challenged guys).

Many of us know and understand the danger in repairing a TV set - not
just you arrogant !@$$%&*.

By the way, I have a PhD in electrical engineering and probably can
run circles around you when it comes to knowledge of electrical
engineering. However, I do not know specifically how to fix a TV and
hence the posting. If I had the time, I can understand the circuit
and then figure out what is wrong. I was hoping that this newsgroup,
with its collective knowledge, will help me fix this. Your arrogant
replies regarding "what is amps" itself shows that you do not have a
clue as to what an "amplifier" is. Take a few educational courses (or
read a book) before you start yelling at people.

Again, this newsgroup is for help. If you can help, please by all
means do so. If you do not understand what an "amps" is, do everyone
a favor and stop wasting bandwidth.

By the way, I am going to check the sync signals (for you stupids, it
is synchronization signals) to see if the problem lies there as
pointed out by more considerate members of this newsgroup. I thank
them.

bharat

 

[Art]

By The Way, the typos are intentional!! Maybe he just understands Phonics??
"Art" <stubby@comcast.net> wrote in message
news:7v2dnQ7PbpkaWwvdRVn-vA@comcast.com...

Absolute WASTE OF MY TIME!!! This flippin bloke is helpless, ignorant,
stupid and don't even realize it. Blantely obvious he does not want
assistance since he bloody knows everything about this device. Cheere,
Mate, have a good live as and Electrical Engineer. I hope I never
encounter any device you had any interest in designing or implimenting.
"Leonard G. Caillouet" <lcaillo_ns_@devoynet.com> wrote in message
news:Xnylc.64982$oN1.49963@bignews5.bellsouth.net...
David is completely correct, video amps don't drive yokes. I suppose
they
didn't teach you that in electrical engineering.

Actually, Q751 and Q752 are convergence amplifiers, not video amplifiers,
and are likely not your problem. If one of these failed you would see
convergence problems, the set would shut down, or it would blow fuse(s)
and
shut down. If you are getting a blue screen it is likely that you have
lost
signal and the set is muting the video. Your problem could be anything
from not knowing how to operate the set to a problem anywhere in the
signal
path.

If you are looking for video amplifiers you are looking in the wrong
area.
You might want to check your assumptions and your reading of the
schematic
before losing it on a forum where you are asking for help. Your post
indicated exactly what David noted, that you may be in over your head.

Now, if you want some help, why not tell us what equipment you have, and
what measurements you have taken and the signal conditions under which
they
were taken. A few of us arrogant morons, as you put it, have quite a lot
of
experience that we might be willing to share. Understand, however, that
if
you don't have the right equipment, knowledge, and troubleshooting
skills,
this may not be a realistic repair for you to attempt.

Your attitude and your PhD will not necessarily help in fixing your set.
A
scope, some humility, and some TV service skills would go a lot farther.

Leonard
Pedantic asshole, maybe...arrogant moron, not usually


"bharat" <bhuva@vuse.vanderbilt.edu> wrote in message
news:27bb423c.0405031126.3a9ffb8d@posting.google.com...
Let me make a few things clear to answer your !@#$%^&*() arrogance.

Video amps are video amplifiers located in Q751 and Q752 on the signal
board. They drive yokes directly. In case any of you arrogant morons
had time and knowledge to understand what a schmatic looks like, you
would clearly see where video amplifiers are located. In adition,
amps is shorthand for amplifiers - any person knowledgable in
Electrical Engineering knows that. Next time, try to understand the
posting before replying. Your assumption that if you do not
understand something then it must be wrong is stupid!

Secondly, a while back in this newsgroup, there was a posting where
someone had green screen problem similar to mine. The solution posted
on the net was that the power supply to video amplifiers was suspect.
Hence my intuition regarding video amps (oops, I mean video amplifiers
for you intellectually-challenged guys).

Many of us know and understand the danger in repairing a TV set - not
just you arrogant !@$$%&*.

By the way, I have a PhD in electrical engineering and probably can
run circles around you when it comes to knowledge of electrical
engineering. However, I do not know specifically how to fix a TV and
hence the posting. If I had the time, I can understand the circuit
and then figure out what is wrong. I was hoping that this newsgroup,
with its collective knowledge, will help me fix this. Your arrogant
replies regarding "what is amps" itself shows that you do not have a
clue as to what an "amplifier" is. Take a few educational courses (or
read a book) before you start yelling at people.

Again, this newsgroup is for help. If you can help, please by all
means do so. If you do not understand what an "amps" is, do everyone
a favor and stop wasting bandwidth.

By the way, I am going to check the sync signals (for you stupids, it
is synchronization signals) to see if the problem lies there as
pointed out by more considerate members of this newsgroup. I thank
them.

bharat

 

[David]

You are still totally clueless. Talk about a worthless phd if you really
have one, which I doubt given the new post where you try and prove that you
know what you are talking about.

Not even close again. Q751 and Q752 are not video amps. (at least you
spelled it correctly this time). They are AUDIO amplifier output ic's being
used as convergence output amplifiers. I totally understood the posting and
the fact that you did not understand electronics enough to try and attempt a
repair.

It is even more clear that you have no business whatever your so called
worthless paper degree is in to be inside the tv attempting a repair on it.
Especially since you cannot read or spell, (apms vs amps, not the same thing
dumbass) doubtful you have any college degree. I pity the reputation of any
college that actually gave you a degree. At least you did not try and call
it 'snyc' this time around.



"bharat" <bhuva@vuse.vanderbilt.edu> wrote in message
news:27bb423c.0405031126.3a9ffb8d@posting.google.com...

Let me make a few things clear to answer your !@#$%^&*() arrogance.

Video amps are video amplifiers located in Q751 and Q752 on the signal
board. They drive yokes directly. In case any of you arrogant morons
had time and knowledge to understand what a schmatic looks like, you
would clearly see where video amplifiers are located. In adition,
amps is shorthand for amplifiers - any person knowledgable in
Electrical Engineering knows that. Next time, try to understand the
posting before replying. Your assumption that if you do not
understand something then it must be wrong is stupid!

Secondly, a while back in this newsgroup, there was a posting where
someone had green screen problem similar to mine. The solution posted
on the net was that the power supply to video amplifiers was suspect.
Hence my intuition regarding video amps (oops, I mean video amplifiers
for you intellectually-challenged guys).

Many of us know and understand the danger in repairing a TV set - not
just you arrogant !@$$%&*.

By the way, I have a PhD in electrical engineering and probably can
run circles around you when it comes to knowledge of electrical
engineering. However, I do not know specifically how to fix a TV and
hence the posting. If I had the time, I can understand the circuit
and then figure out what is wrong. I was hoping that this newsgroup,
with its collective knowledge, will help me fix this. Your arrogant
replies regarding "what is amps" itself shows that you do not have a
clue as to what an "amplifier" is. Take a few educational courses (or
read a book) before you start yelling at people.

Again, this newsgroup is for help. If you can help, please by all
means do so. If you do not understand what an "amps" is, do everyone
a favor and stop wasting bandwidth.

By the way, I am going to check the sync signals (for you stupids, it
is synchronization signals) to see if the problem lies there as
pointed out by more considerate members of this newsgroup. I thank
them.

bharat

 

[David]

If you only knew how sub-standard some college education really is these
days, you would laugh.

Some words of wisdom from my Father who hired engineers:

Those that can do, those that can't teach.
Never ever hire an engineer that was not a technician first, they cannot
troubleshoot thier way out of a paperbag.

"Art" <stubby@comcast.net> wrote in message
news:NYednaDlcu1lWgvd4p2dnA@comcast.com...

By The Way, the typos are intentional!! Maybe he just understands
Phonics??
"Art" <stubby@comcast.net> wrote in message
news:7v2dnQ7PbpkaWwvdRVn-vA@comcast.com...
Absolute WASTE OF MY TIME!!! This flippin bloke is helpless, ignorant,
stupid and don't even realize it. Blantely obvious he does not want
assistance since he bloody knows everything about this device. Cheere,
Mate, have a good live as and Electrical Engineer. I hope I never
encounter any device you had any interest in designing or implimenting.
"Leonard G. Caillouet" <lcaillo_ns_@devoynet.com> wrote in message
news:Xnylc.64982$oN1.49963@bignews5.bellsouth.net...
David is completely correct, video amps don't drive yokes. I suppose
they
didn't teach you that in electrical engineering.

Actually, Q751 and Q752 are convergence amplifiers, not video
amplifiers,
and are likely not your problem. If one of these failed you would see
convergence problems, the set would shut down, or it would blow fuse(s)
and
shut down. If you are getting a blue screen it is likely that you have
lost
signal and the set is muting the video. Your problem could be
anything
from not knowing how to operate the set to a problem anywhere in the
signal
path.

If you are looking for video amplifiers you are looking in the wrong
area.
You might want to check your assumptions and your reading of the
schematic
before losing it on a forum where you are asking for help. Your post
indicated exactly what David noted, that you may be in over your head.

Now, if you want some help, why not tell us what equipment you have,
and
what measurements you have taken and the signal conditions under which
they
were taken. A few of us arrogant morons, as you put it, have quite a
lot
of
experience that we might be willing to share. Understand, however,
that
if
you don't have the right equipment, knowledge, and troubleshooting
skills,
this may not be a realistic repair for you to attempt.

Your attitude and your PhD will not necessarily help in fixing your
set.
A
scope, some humility, and some TV service skills would go a lot
farther.

Leonard
Pedantic asshole, maybe...arrogant moron, not usually


"bharat" <bhuva@vuse.vanderbilt.edu> wrote in message
news:27bb423c.0405031126.3a9ffb8d@posting.google.com...
Let me make a few things clear to answer your !@#$%^&*() arrogance.

Video amps are video amplifiers located in Q751 and Q752 on the signal
board. They drive yokes directly. In case any of you arrogant morons
had time and knowledge to understand what a schmatic looks like, you
would clearly see where video amplifiers are located. In adition,
amps is shorthand for amplifiers - any person knowledgable in
Electrical Engineering knows that. Next time, try to understand the
posting before replying. Your assumption that if you do not
understand something then it must be wrong is stupid!

Secondly, a while back in this newsgroup, there was a posting where
someone had green screen problem similar to mine. The solution posted
on the net was that the power supply to video amplifiers was suspect.
Hence my intuition regarding video amps (oops, I mean video amplifiers
for you intellectually-challenged guys).

Many of us know and understand the danger in repairing a TV set - not
just you arrogant !@$$%&*.

By the way, I have a PhD in electrical engineering and probably can
run circles around you when it comes to knowledge of electrical
engineering. However, I do not know specifically how to fix a TV and
hence the posting. If I had the time, I can understand the circuit
and then figure out what is wrong. I was hoping that this newsgroup,
with its collective knowledge, will help me fix this. Your arrogant
replies regarding "what is amps" itself shows that you do not have a
clue as to what an "amplifier" is. Take a few educational courses (or
read a book) before you start yelling at people.

Again, this newsgroup is for help. If you can help, please by all
means do so. If you do not understand what an "amps" is, do everyone
a favor and stop wasting bandwidth.

By the way, I am going to check the sync signals (for you stupids, it
is synchronization signals) to see if the problem lies there as
pointed out by more considerate members of this newsgroup. I thank
them.

bharat

 

[bharat]

I haven't had this many arguments over a posting for a long time!!

I own another 52H72 and have troubleshot the power board without any
problem (it did take me a whole weekend to do it). That set kept
turning on and off. I was hoping to avoid a repeat of my "lost"
weekend. I wanted someone to point out the area I should be checking.
I am not that familiar with the signal board and I believe people on
the net have more experience than I will ever have repairing a TV.
Hence the post. I did not want to post a lengthy note on what tests I
did (I checked all power supply lines, H-sync, and yoke drivers. I
have multimeters and a simple oscilloscope). I went through the
schematic. Went through this newsgroup. A previous post mentioned
video amps. There were amplifiers driving the yokes. I assumed that
is what the previous message was talking about when it said video
amps.

If I was wrong, please point it out and point me in the correct
direction. Pointing out my inexperience in repairing a TV is
acceptable, but not providing help and flaming me is not OK. There
are hundreds of postings each day here. If you can't provide help,
don't say anything. Everyone who reads this newsgroup knows (a) a lot
of novices are attempting TV repair who should not, (b) TV repair is
dangerous business, (c) most of these novices will harm themselves
(darwinian principle at work) and learn along the way not to do it
again (as David's post pointed out about the guy who burned his house
down).

Please do not assume that someone is not capable of understanding
things regarding TV and repairing it. With a little help and some
precautions (and common sense about electrical engineering), competent
people can repair TVs. Newsgroups like this one certainly helps.

I did not mean to offend collectively everyone (I was thinking no one
will read this posting because it was old. And only David and I will
scream at each other for a day and then forget about it). Obviously
that is not the case.

I am going to check yokes and sync signals. Hopefully, that will tell
me more about where to go. Thanks for all the help.

bharat

 

[Ken Weitzel]

bharat wrote:

I haven't had this many arguments over a posting for a long time!!

I own another 52H72 and have troubleshot the power board without any
problem (it did take me a whole weekend to do it). That set kept
turning on and off. I was hoping to avoid a repeat of my "lost"
weekend. I wanted someone to point out the area I should be checking.
I am not that familiar with the signal board and I believe people on
the net have more experience than I will ever have repairing a TV.
Hence the post. I did not want to post a lengthy note on what tests I
did (I checked all power supply lines, H-sync, and yoke drivers. I
have multimeters and a simple oscilloscope). I went through the
schematic. Went through this newsgroup. A previous post mentioned
video amps. There were amplifiers driving the yokes. I assumed that
is what the previous message was talking about when it said video
amps.

If I was wrong, please point it out and point me in the correct
direction. Pointing out my inexperience in repairing a TV is
acceptable, but not providing help and flaming me is not OK. There
are hundreds of postings each day here. If you can't provide help,
don't say anything. Everyone who reads this newsgroup knows (a) a lot
of novices are attempting TV repair who should not, (b) TV repair is
dangerous business, (c) most of these novices will harm themselves
(darwinian principle at work) and learn along the way not to do it
again (as David's post pointed out about the guy who burned his house
down).

Please do not assume that someone is not capable of understanding
things regarding TV and repairing it. With a little help and some
precautions (and common sense about electrical engineering), competent
people can repair TVs. Newsgroups like this one certainly helps.

I did not mean to offend collectively everyone (I was thinking no one
will read this posting because it was old. And only David and I will
scream at each other for a day and then forget about it). Obviously
that is not the case.

I am going to check yokes and sync signals. Hopefully, that will tell
me more about where to go. Thanks for all the help.

bharat

Hi...

Seeing as this message is a tiny bit apologetic, and a
lot less arrogant, I'll take a chance and try again...
hopefully a little has been learned (on both sides) and
a fresh start is possible.

I'll apologize for my message agreeing (sarcastically)
with you, and hope we can do better.

So, having said that, I'm an old stroke damaged
retired guy who hasn't been in the picture for
several years... just keeping in touch, so don't
take my word either as gospel, or current

What got everyone's dander up started with the yoke.
The yoke has absolutely nothing, repeat nothing to
do with your current problem. The yoke is that
round coils of wire on the neck of the picture tube,
pushed snugly up against the "flare" of the tube.
It's sole purpose in life is deflection. It's
driven by the horizontal and vertical ouputs.
If the horizontal portion fails, you'll be left
with (theoretically only) a bright white vertical
line. If the vertical fails, you'll be left with
(in reality) a straight white horizontal line across
the center of the crt.

So, let's leave the yoke out of it.

Sync is responsible for synchronizing that
vertical and horizontal deflection... failure
will give you a "rolling" picture (vertical fail)
or one that won't "stand straight up.

So let's leave sync out of it.

What have we left that IS perhaps responsible?

Well, there is a possibility that the blue grid
in the crt is shorted. This almost certainly makes
the set not worth repair.

There are drivers (transistors), one for each colour.
These are most likely located on the pcb which is
plugged onto the picture tube socket. The possiblity
is that one is shorted. Check them easily enough
by simply comparing them one against another with
the other "set"

Further than that I cannot go, not knowing your
set or even much of the state of the art.

But it's a start in the right direction, and perhaps
can lead to more.

I'll take a chance and give you one tiny little
lecture and life lesson. I raised many kids,
(all girls) and now am an old man all alone raising
(trying) a just turned teenage grand daughter.
I told each of them, and now I tell you, that how
you treat other people is going to make a bigger
difference in you life than any other thing you
can do. More important than education, than skills,
than wealth, than appearance, anything.

Let's see where we go from here.

Good luck, and take care.

Ken

 

[David]

Answer these questions and you might be able to narrow it down.
Do you have a schematic?
When the picture appears, does the color look good for the second? If so
the tv is probably going into blue screen mute.
Look to the system control (aka microcontroller/ micro) ic that basically
runs everything first.
You will may find OSD outputs RGB going to the jungle ic (term for the big
signal process ic that does most everything). Look at the RBG outputs to
see if the blue is on (more or less) all the time. If it is the micro is
definitely putting the tv into blue screen mute. Then look for the signal
sync going into the micro to see if it is present.

The micro has several must signals in order to display a picture. H-sync
(horizontal feedback sync from deflection) set will usually turn off if
missing right away, V-Sync (vertical feedback sync from deflection) tv will
typically shut down after 2 to 3 seconds, 60Hz clock signal from the ac
power line (different sets behave strangely, could cause blue screen mute),
a serial clock and data handshake from several other ics on the databus
(since manufactures do not provide enough information to actually
troubleshoot this, swap a part until it works, some tv sets have a computer
interface and error code service mode to help), of course the micro needs
the signal sync in order to know there is an image to display, we cannot
forget about the AKB (auto-kine-bias) circuits on the picture tubes which
can blank the video completely.

Simple troubleshooting:
1. Since the menu works, and if the audio goes up and down, or different
video inputs can be selected via the remote control. This indicates that at
least the data buss is functional and the ics are communications. It does
not mean there not an ic that is not sending the all ok signal to the micro
however.
2. Since the video comes on for a second when immediately switching inputs,
the set is most likely in blue screen mute.
3. If the blue screen does not have the 10-12 visible diagonal retrace
lines, this pretty much rules out the video output stages.
4. Try the s-video or component inputs to see if they work as well. If the
s-video works, it means there is a problem before or including the comb
filter. If only the component video works even more of the signal circuit
has been eliminated.
5. Do not forget that this device has virtually all of its functional
parameters (adjustments) set by an eeprom and service menu. Corrupted data
in the wrong location can cause the same symptoms as actual parts failures.

As an added note, I strongly recommend you use an isolation transformer for
the tv set whenever working on it with the back removed. It will provide a
level of safety to yourself and your test equipment that no measure of being
careful can achieve. Even though that set uses a SMPS to provide isolation,
there are still exposed components and traces tied directly to the AC power
line source.

After doing some research, I found out you really are at least a Professor
at a college or university so you might have a PhD afterall, sorry for
doubting your word. Don't take anything personal as it is hard to judge the
character of someone from inaccurate information posted on the web. I have
to go by experience and it has not been a good one with some people, as
indicated with the fire and lawsuit.

I have taught unemployed engineers in a course where they were retraining to
become technicians. They were by far the worst students at "getting it"
when it came to real world troubleshooting and circuit behavior.

It should take about 15 minutes maximum to narrow down a close location of
the problem.
I always check the required stuff before going in very deep. Proper and
clean Vcc and Vdd votlages. All the correct signals to the system control,
60Hz ac pulse, H-sync, V-sync, Signal sync, clean Vcc, etc. Then move to
the jungle ic. If the Signal sync is found missing or small, simply start
tracing it back to its source (near the jungle ic I am sure).
"bharat" <bhuva@vuse.vanderbilt.edu> wrote in message
news:27bb423c.0405041714.3997d4fb@posting.google.com...

I haven't had this many arguments over a posting for a long time!!

I own another 52H72 and have troubleshot the power board without any
problem (it did take me a whole weekend to do it). That set kept
turning on and off. I was hoping to avoid a repeat of my "lost"
weekend. I wanted someone to point out the area I should be checking.
I am not that familiar with the signal board and I believe people on
the net have more experience than I will ever have repairing a TV.
Hence the post. I did not want to post a lengthy note on what tests I
did (I checked all power supply lines, H-sync, and yoke drivers. I
have multimeters and a simple oscilloscope). I went through the
schematic. Went through this newsgroup. A previous post mentioned
video amps. There were amplifiers driving the yokes. I assumed that
is what the previous message was talking about when it said video
amps.

If I was wrong, please point it out and point me in the correct
direction. Pointing out my inexperience in repairing a TV is
acceptable, but not providing help and flaming me is not OK. There
are hundreds of postings each day here. If you can't provide help,
don't say anything. Everyone who reads this newsgroup knows (a) a lot
of novices are attempting TV repair who should not, (b) TV repair is
dangerous business, (c) most of these novices will harm themselves
(darwinian principle at work) and learn along the way not to do it
again (as David's post pointed out about the guy who burned his house
down).

Please do not assume that someone is not capable of understanding
things regarding TV and repairing it. With a little help and some
precautions (and common sense about electrical engineering), competent
people can repair TVs. Newsgroups like this one certainly helps.

I did not mean to offend collectively everyone (I was thinking no one
will read this posting because it was old. And only David and I will
scream at each other for a day and then forget about it). Obviously
that is not the case.

I am going to check yokes and sync signals. Hopefully, that will tell
me more about where to go. Thanks for all the help.

bharat