Zenith SR3587DT Sound OK, No Picture????

Q

Q.E.D.

Guest
Looking for input into whether this June 1996 build TV is worth having
repaired.

TV has worked great since purchase in 1996. Never got a great deal of
use...maybe 10 hours a week on weekends to watch mainly movies on DVD
or HBO. I figure less than 4000 hours total use. Set had been on for
about 4 hours one day and the picture just went blank...like someone
turned it off. No warning of trouble before that...no picture fade or
blooming, it just went dark. Sound still works OK.

The TV is long out of warranty but due to it's light use I was
thinking it might be worth repairing. Can anyone give me an idea how
much would be a fair rate for a repairman to come out and diagnose (I
live in Philadelphia, PA)? What's an average repair cost on a 35"
set? I realize the repair costs would be on top of the initial
estimate depending on what is wrong. On that note, are my TV's
symptoms indicative of a common problem? Based on my novice research
I think it could be a high voltage problem.

The neighborhood repair guy went out of business about three years
ago. Choosing a repair service, I'm finding, is almost impossible to
decide on blindly.

Any advice would be appreciated.

Thanks
 
Could be as simple as the 110k ohm resistor that connects to the H.O.T. or a
bad flyback.
You really should contact Zenith and ask for a local authorized servicer.
Try www.zenith.com

Good Luck,
Bill Jr


"Q.E.D." <qed@verizon.net> wrote in message
news:f7tlivg8e0atun19067h7feu8qt0d94drm@4ax.com...
Looking for input into whether this June 1996 build TV is worth having
repaired.

TV has worked great since purchase in 1996. Never got a great deal of
use...maybe 10 hours a week on weekends to watch mainly movies on DVD
or HBO. I figure less than 4000 hours total use. Set had been on for
about 4 hours one day and the picture just went blank...like someone
turned it off. No warning of trouble before that...no picture fade or
blooming, it just went dark. Sound still works OK.

The TV is long out of warranty but due to it's light use I was
thinking it might be worth repairing. Can anyone give me an idea how
much would be a fair rate for a repairman to come out and diagnose (I
live in Philadelphia, PA)? What's an average repair cost on a 35"
set? I realize the repair costs would be on top of the initial
estimate depending on what is wrong. On that note, are my TV's
symptoms indicative of a common problem? Based on my novice research
I think it could be a high voltage problem.

The neighborhood repair guy went out of business about three years
ago. Choosing a repair service, I'm finding, is almost impossible to
decide on blindly.

Any advice would be appreciated.

Thanks
Click to expand...
 
im sure you all know me by now,

but I had the same problem with mine, NO HV, and i have narrowed it down to
the scan gen circuits, it wasnt spitting out a waveform, not even a startup
pulse.

I found a scope mod that can ring check the flyback, and it checks good, so
only thing left: Scan Gen IC. which the shutdown sequence is computer
controlled.

I NEED TO DISABLE THE SHUTDOWN TO TEST FURTHER. anyone got any insight on
this?




"Bill Jr" <bill@nospam.usa2net.net> wrote in message
news:kPDWa.6004$On2.407147@twister.tampabay.rr.com...
Could be as simple as the 110k ohm resistor that connects to the H.O.T. or
a
bad flyback.
You really should contact Zenith and ask for a local authorized servicer.
Try www.zenith.com

Good Luck,
Bill Jr


"Q.E.D." <qed@verizon.net> wrote in message
news:f7tlivg8e0atun19067h7feu8qt0d94drm@4ax.com...
Looking for input into whether this June 1996 build TV is worth having
repaired.

TV has worked great since purchase in 1996. Never got a great deal of
use...maybe 10 hours a week on weekends to watch mainly movies on DVD
or HBO. I figure less than 4000 hours total use. Set had been on for
about 4 hours one day and the picture just went blank...like someone
turned it off. No warning of trouble before that...no picture fade or
blooming, it just went dark. Sound still works OK.

The TV is long out of warranty but due to it's light use I was
thinking it might be worth repairing. Can anyone give me an idea how
much would be a fair rate for a repairman to come out and diagnose (I
live in Philadelphia, PA)? What's an average repair cost on a 35"
set? I realize the repair costs would be on top of the initial
estimate depending on what is wrong. On that note, are my TV's
symptoms indicative of a common problem? Based on my novice research
I think it could be a high voltage problem.

The neighborhood repair guy went out of business about three years
ago. Choosing a repair service, I'm finding, is almost impossible to
decide on blindly.

Any advice would be appreciated.

Thanks
Click to expand...
 
Module exchange will rebuilt the main board for around 100.00 call them

http://www.tvparts.com/


"Q.E.D." <qed@verizon.net> wrote in message
news:f7tlivg8e0atun19067h7feu8qt0d94drm@4ax.com...
Looking for input into whether this June 1996 build TV is worth having
repaired.

TV has worked great since purchase in 1996. Never got a great deal of
use...maybe 10 hours a week on weekends to watch mainly movies on DVD
or HBO. I figure less than 4000 hours total use. Set had been on for
about 4 hours one day and the picture just went blank...like someone
turned it off. No warning of trouble before that...no picture fade or
blooming, it just went dark. Sound still works OK.

The TV is long out of warranty but due to it's light use I was
thinking it might be worth repairing. Can anyone give me an idea how
much would be a fair rate for a repairman to come out and diagnose (I
live in Philadelphia, PA)? What's an average repair cost on a 35"
set? I realize the repair costs would be on top of the initial
estimate depending on what is wrong. On that note, are my TV's
symptoms indicative of a common problem? Based on my novice research
I think it could be a high voltage problem.

The neighborhood repair guy went out of business about three years
ago. Choosing a repair service, I'm finding, is almost impossible to
decide on blindly.

Any advice would be appreciated.

Thanks
Click to expand...
 
see, thats the problem. I live off of social security, and I dont have 100
dollars to put in a board.

I understand the flyback is 60, but its not bad. I ring tested it.

I need to disable shutdown of the scan circuity, and someone here with a
schematic can tell me.







"Mr. Lee" <bubba@biff.com> wrote in message
news:itOWa.211635$o86.31719@news1.central.cox.net...
Module exchange will rebuilt the main board for around 100.00 call them

http://www.tvparts.com/


"Q.E.D." <qed@verizon.net> wrote in message
news:f7tlivg8e0atun19067h7feu8qt0d94drm@4ax.com...
Looking for input into whether this June 1996 build TV is worth having
repaired.

TV has worked great since purchase in 1996. Never got a great deal of
use...maybe 10 hours a week on weekends to watch mainly movies on DVD
or HBO. I figure less than 4000 hours total use. Set had been on for
about 4 hours one day and the picture just went blank...like someone
turned it off. No warning of trouble before that...no picture fade or
blooming, it just went dark. Sound still works OK.

The TV is long out of warranty but due to it's light use I was
thinking it might be worth repairing. Can anyone give me an idea how
much would be a fair rate for a repairman to come out and diagnose (I
live in Philadelphia, PA)? What's an average repair cost on a 35"
set? I realize the repair costs would be on top of the initial
estimate depending on what is wrong. On that note, are my TV's
symptoms indicative of a common problem? Based on my novice research
I think it could be a high voltage problem.

The neighborhood repair guy went out of business about three years
ago. Choosing a repair service, I'm finding, is almost impossible to
decide on blindly.

Any advice would be appreciated.

Thanks
Click to expand...
 
BTW, i dont have a remote for it, to get into service menu, but of course it
doesnt matter, because there is no HV, raster, or filiment. Just sound.




"Mike" <mbates14@fuse.net> wrote in message
news:a9QWa.33153$hc.33031@fe3.columbus.rr.com...
see, thats the problem. I live off of social security, and I dont have 100
dollars to put in a board.

I understand the flyback is 60, but its not bad. I ring tested it.

I need to disable shutdown of the scan circuity, and someone here with a
schematic can tell me.







"Mr. Lee" <bubba@biff.com> wrote in message
news:itOWa.211635$o86.31719@news1.central.cox.net...
Module exchange will rebuilt the main board for around 100.00 call them

http://www.tvparts.com/


"Q.E.D." <qed@verizon.net> wrote in message
news:f7tlivg8e0atun19067h7feu8qt0d94drm@4ax.com...
Looking for input into whether this June 1996 build TV is worth having
repaired.

TV has worked great since purchase in 1996. Never got a great deal of
use...maybe 10 hours a week on weekends to watch mainly movies on DVD
or HBO. I figure less than 4000 hours total use. Set had been on for
about 4 hours one day and the picture just went blank...like someone
turned it off. No warning of trouble before that...no picture fade or
blooming, it just went dark. Sound still works OK.

The TV is long out of warranty but due to it's light use I was
thinking it might be worth repairing. Can anyone give me an idea how
much would be a fair rate for a repairman to come out and diagnose (I
live in Philadelphia, PA)? What's an average repair cost on a 35"
set? I realize the repair costs would be on top of the initial
estimate depending on what is wrong. On that note, are my TV's
symptoms indicative of a common problem? Based on my novice research
I think it could be a high voltage problem.

The neighborhood repair guy went out of business about three years
ago. Choosing a repair service, I'm finding, is almost impossible to
decide on blindly.

Any advice would be appreciated.

Thanks
Click to expand...
 
DO NOT disable the shutdown ,are you stupid ?
Its there for the TV,s and your protection .
kip

I need to disable shutdown of the scan circuity, and someone here with a
schematic can tell me.
Click to expand...
 
yea im stupid, if thats the only way to find out whats wrong, because other
approatches just arnt working.

like, The HOT has B+, flyback rings good, but

there is NO drive signal from the scan IC for the horiz or vert. so im
suspecting that the IC is either in shutdown, or is bad.

there isnt even a startup pulse, and I thought that the startup pulse has to
be there in order to get feedback from the flyback to shut it down. Is this
true?

if so, there isnt any.




"john" <va3mm@niagara.com> wrote in message
news:newscache$plzzih$pg4$1@newsfeed.niagara.com...
DO NOT disable the shutdown ,are you stupid ?
Its there for the TV,s and your protection .
kip


I need to disable shutdown of the scan circuity, and someone here with a
schematic can tell me.
Click to expand...
 
You cannot do it. Disable the xray protect in that set.

Just because the flyback ring tests ok does not mean it is good, means it
does not have excessive shorted windings. Zenith flybacks are well known
for having the triplers go bad, you will be able to read some resistance
between the hv anode and the ground of the flyback, usually around 400K when
they are bad.

The 35" in that era is also well known for the shaping coil and pin cushion
coils shorting out internally. There is a fuse in series with the voltage
to the flyback for the main b+, without it present you also will not get any
drive pulses.


Mike <mbates14@fuse.net> wrote in message
news:IsQWa.33200$hc.5762@fe3.columbus.rr.com...
BTW, i dont have a remote for it, to get into service menu, but of course
it
doesnt matter, because there is no HV, raster, or filiment. Just sound.




"Mike" <mbates14@fuse.net> wrote in message
news:a9QWa.33153$hc.33031@fe3.columbus.rr.com...
see, thats the problem. I live off of social security, and I dont have
100
dollars to put in a board.

I understand the flyback is 60, but its not bad. I ring tested it.

I need to disable shutdown of the scan circuity, and someone here with a
schematic can tell me.







"Mr. Lee" <bubba@biff.com> wrote in message
news:itOWa.211635$o86.31719@news1.central.cox.net...
Module exchange will rebuilt the main board for around 100.00 call
them

http://www.tvparts.com/


"Q.E.D." <qed@verizon.net> wrote in message
news:f7tlivg8e0atun19067h7feu8qt0d94drm@4ax.com...
Looking for input into whether this June 1996 build TV is worth
having
repaired.

TV has worked great since purchase in 1996. Never got a great deal
of
use...maybe 10 hours a week on weekends to watch mainly movies on
DVD
or HBO. I figure less than 4000 hours total use. Set had been on
for
about 4 hours one day and the picture just went blank...like someone
turned it off. No warning of trouble before that...no picture fade
or
blooming, it just went dark. Sound still works OK.

The TV is long out of warranty but due to it's light use I was
thinking it might be worth repairing. Can anyone give me an idea
how
much would be a fair rate for a repairman to come out and diagnose
(I
live in Philadelphia, PA)? What's an average repair cost on a 35"
set? I realize the repair costs would be on top of the initial
estimate depending on what is wrong. On that note, are my TV's
symptoms indicative of a common problem? Based on my novice
research
I think it could be a high voltage problem.

The neighborhood repair guy went out of business about three years
ago. Choosing a repair service, I'm finding, is almost impossible
to
decide on blindly.

Any advice would be appreciated.

Thanks
Click to expand...
 
ok, I finally got to it.


All volteges are presant and none of the fuses are blown.

now, there was a pin problem.

Now, I set my scope up, and did some more testing on the tv,

the scan gen IS working. there is a square wave pulse on the pin 8. there is
a square wave pulse on the base of the horizontal driver transistor. BUT,
there is NO DRIVE PULSE on the collector of the driver transistor. so, i
guess its a bad transistor. I did some voltege measurements, and there is
about 41VDC on the collector.

There is 158VDC B+ on the HOT.

I did a BtoC, and BtoE check in circuit on the transistor, and it checks OK,
but i never pulled it out of circuit.

Any Ideas?








"Q.E.D." <qed@verizon.net> wrote in message
news:f7tlivg8e0atun19067h7feu8qt0d94drm@4ax.com...
Looking for input into whether this June 1996 build TV is worth having
repaired.

TV has worked great since purchase in 1996. Never got a great deal of
use...maybe 10 hours a week on weekends to watch mainly movies on DVD
or HBO. I figure less than 4000 hours total use. Set had been on for
about 4 hours one day and the picture just went blank...like someone
turned it off. No warning of trouble before that...no picture fade or
blooming, it just went dark. Sound still works OK.

The TV is long out of warranty but due to it's light use I was
thinking it might be worth repairing. Can anyone give me an idea how
much would be a fair rate for a repairman to come out and diagnose (I
live in Philadelphia, PA)? What's an average repair cost on a 35"
set? I realize the repair costs would be on top of the initial
estimate depending on what is wrong. On that note, are my TV's
symptoms indicative of a common problem? Based on my novice research
I think it could be a high voltage problem.

The neighborhood repair guy went out of business about three years
ago. Choosing a repair service, I'm finding, is almost impossible to
decide on blindly.

Any advice would be appreciated.

Thanks
Click to expand...
 
P.S., the heatsink on the QX3201 stays cool.

the other 3 in the chopper circuit get regularly warm, thats the only one
that stays cold.

could that be something? it junction tests good.




"Mike" <mbates14@fuse.net> wrote in message
news:LsUWa.34403$hc.14392@fe3.columbus.rr.com...
ok, I finally got to it.


All volteges are presant and none of the fuses are blown.

now, there was a pin problem.

Now, I set my scope up, and did some more testing on the tv,

the scan gen IS working. there is a square wave pulse on the pin 8. there
is
a square wave pulse on the base of the horizontal driver transistor. BUT,
there is NO DRIVE PULSE on the collector of the driver transistor. so, i
guess its a bad transistor. I did some voltege measurements, and there is
about 41VDC on the collector.

There is 158VDC B+ on the HOT.

I did a BtoC, and BtoE check in circuit on the transistor, and it checks
OK,
but i never pulled it out of circuit.

Any Ideas?








"Q.E.D." <qed@verizon.net> wrote in message
news:f7tlivg8e0atun19067h7feu8qt0d94drm@4ax.com...
Looking for input into whether this June 1996 build TV is worth having
repaired.

TV has worked great since purchase in 1996. Never got a great deal of
use...maybe 10 hours a week on weekends to watch mainly movies on DVD
or HBO. I figure less than 4000 hours total use. Set had been on for
about 4 hours one day and the picture just went blank...like someone
turned it off. No warning of trouble before that...no picture fade or
blooming, it just went dark. Sound still works OK.

The TV is long out of warranty but due to it's light use I was
thinking it might be worth repairing. Can anyone give me an idea how
much would be a fair rate for a repairman to come out and diagnose (I
live in Philadelphia, PA)? What's an average repair cost on a 35"
set? I realize the repair costs would be on top of the initial
estimate depending on what is wrong. On that note, are my TV's
symptoms indicative of a common problem? Based on my novice research
I think it could be a high voltage problem.

The neighborhood repair guy went out of business about three years
ago. Choosing a repair service, I'm finding, is almost impossible to
decide on blindly.

Any advice would be appreciated.

Thanks
Click to expand...
 
oh yea, one more thing, the square wave pulse is continuos, its not shutting
down, probably because its not getting to the flyback, or the base of the
HOT, it dies off at the driver xistor. its there on the base, gone on the
collector






"Mike" <mbates14@fuse.net> wrote in message
news:syUWa.34437$hc.14352@fe3.columbus.rr.com...
P.S., the heatsink on the QX3201 stays cool.

the other 3 in the chopper circuit get regularly warm, thats the only one
that stays cold.

could that be something? it junction tests good.




"Mike" <mbates14@fuse.net> wrote in message
news:LsUWa.34403$hc.14392@fe3.columbus.rr.com...
ok, I finally got to it.


All volteges are presant and none of the fuses are blown.

now, there was a pin problem.

Now, I set my scope up, and did some more testing on the tv,

the scan gen IS working. there is a square wave pulse on the pin 8.
there
is
a square wave pulse on the base of the horizontal driver transistor.
BUT,
there is NO DRIVE PULSE on the collector of the driver transistor. so, i
guess its a bad transistor. I did some voltege measurements, and there
is
about 41VDC on the collector.

There is 158VDC B+ on the HOT.

I did a BtoC, and BtoE check in circuit on the transistor, and it checks
OK,
but i never pulled it out of circuit.

Any Ideas?








"Q.E.D." <qed@verizon.net> wrote in message
news:f7tlivg8e0atun19067h7feu8qt0d94drm@4ax.com...
Looking for input into whether this June 1996 build TV is worth having
repaired.

TV has worked great since purchase in 1996. Never got a great deal of
use...maybe 10 hours a week on weekends to watch mainly movies on DVD
or HBO. I figure less than 4000 hours total use. Set had been on for
about 4 hours one day and the picture just went blank...like someone
turned it off. No warning of trouble before that...no picture fade or
blooming, it just went dark. Sound still works OK.

The TV is long out of warranty but due to it's light use I was
thinking it might be worth repairing. Can anyone give me an idea how
much would be a fair rate for a repairman to come out and diagnose (I
live in Philadelphia, PA)? What's an average repair cost on a 35"
set? I realize the repair costs would be on top of the initial
estimate depending on what is wrong. On that note, are my TV's
symptoms indicative of a common problem? Based on my novice research
I think it could be a high voltage problem.

The neighborhood repair guy went out of business about three years
ago. Choosing a repair service, I'm finding, is almost impossible to
decide on blindly.

Any advice would be appreciated.

Thanks
Click to expand...
 
one more thing, the square wave pulse is continous, its not shutting
down, probably because its not getting to the flyback, or the base of the
HOT, it dies off at the driver xistor. its there on the base, gone on the
collector









"Q.E.D." <qed@verizon.net> wrote in message
news:f7tlivg8e0atun19067h7feu8qt0d94drm@4ax.com...
Looking for input into whether this June 1996 build TV is worth having
repaired.

TV has worked great since purchase in 1996. Never got a great deal of
use...maybe 10 hours a week on weekends to watch mainly movies on DVD
or HBO. I figure less than 4000 hours total use. Set had been on for
about 4 hours one day and the picture just went blank...like someone
turned it off. No warning of trouble before that...no picture fade or
blooming, it just went dark. Sound still works OK.

The TV is long out of warranty but due to it's light use I was
thinking it might be worth repairing. Can anyone give me an idea how
much would be a fair rate for a repairman to come out and diagnose (I
live in Philadelphia, PA)? What's an average repair cost on a 35"
set? I realize the repair costs would be on top of the initial
estimate depending on what is wrong. On that note, are my TV's
symptoms indicative of a common problem? Based on my novice research
I think it could be a high voltage problem.

The neighborhood repair guy went out of business about three years
ago. Choosing a repair service, I'm finding, is almost impossible to
decide on blindly.

Any advice would be appreciated.

Thanks
Click to expand...
 
IS the frequency of that square wave accurate?
IS the amplitude sufficient to turn on the horiz driver transistor?

Bill Jr


"Mike" <mbates14@fuse.net> wrote in message
news:syUWa.34437$hc.14352@fe3.columbus.rr.com...
P.S., the heatsink on the QX3201 stays cool.

the other 3 in the chopper circuit get regularly warm, thats the only one
that stays cold.

could that be something? it junction tests good.




"Mike" <mbates14@fuse.net> wrote in message
news:LsUWa.34403$hc.14392@fe3.columbus.rr.com...
ok, I finally got to it.


All volteges are presant and none of the fuses are blown.

now, there was a pin problem.

Now, I set my scope up, and did some more testing on the tv,

the scan gen IS working. there is a square wave pulse on the pin 8.
there
is
a square wave pulse on the base of the horizontal driver transistor.
BUT,
there is NO DRIVE PULSE on the collector of the driver transistor. so, i
guess its a bad transistor. I did some voltege measurements, and there
is
about 41VDC on the collector.

There is 158VDC B+ on the HOT.

I did a BtoC, and BtoE check in circuit on the transistor, and it checks
OK,
but i never pulled it out of circuit.

Any Ideas?








"Q.E.D." <qed@verizon.net> wrote in message
news:f7tlivg8e0atun19067h7feu8qt0d94drm@4ax.com...
Looking for input into whether this June 1996 build TV is worth having
repaired.

TV has worked great since purchase in 1996. Never got a great deal of
use...maybe 10 hours a week on weekends to watch mainly movies on DVD
or HBO. I figure less than 4000 hours total use. Set had been on for
about 4 hours one day and the picture just went blank...like someone
turned it off. No warning of trouble before that...no picture fade or
blooming, it just went dark. Sound still works OK.

The TV is long out of warranty but due to it's light use I was
thinking it might be worth repairing. Can anyone give me an idea how
much would be a fair rate for a repairman to come out and diagnose (I
live in Philadelphia, PA)? What's an average repair cost on a 35"
set? I realize the repair costs would be on top of the initial
estimate depending on what is wrong. On that note, are my TV's
symptoms indicative of a common problem? Based on my novice research
I think it could be a high voltage problem.

The neighborhood repair guy went out of business about three years
ago. Choosing a repair service, I'm finding, is almost impossible to
decide on blindly.

Any advice would be appreciated.

Thanks
Click to expand...
 
i dunno.

I just have an older scope.

Its a square wave. typical old squarewave.

I seen a picture of the CTC130 square wave in my tv repair handbook, it
peaks out at the top of each wave, well, this one is jsut square wave. I
have to put my sope on 5V to see the drops and rises.





"Bill Jr" <bill@nospam.usa2net.net> wrote in message
news:1IUWa.10985$K4.455734@twister.tampabay.rr.com...
IS the frequency of that square wave accurate?
IS the amplitude sufficient to turn on the horiz driver transistor?

Bill Jr


"Mike" <mbates14@fuse.net> wrote in message
news:syUWa.34437$hc.14352@fe3.columbus.rr.com...
P.S., the heatsink on the QX3201 stays cool.

the other 3 in the chopper circuit get regularly warm, thats the only
one
that stays cold.

could that be something? it junction tests good.




"Mike" <mbates14@fuse.net> wrote in message
news:LsUWa.34403$hc.14392@fe3.columbus.rr.com...
ok, I finally got to it.


All volteges are presant and none of the fuses are blown.

now, there was a pin problem.

Now, I set my scope up, and did some more testing on the tv,

the scan gen IS working. there is a square wave pulse on the pin 8.
there
is
a square wave pulse on the base of the horizontal driver transistor.
BUT,
there is NO DRIVE PULSE on the collector of the driver transistor. so,
i
guess its a bad transistor. I did some voltege measurements, and there
is
about 41VDC on the collector.

There is 158VDC B+ on the HOT.

I did a BtoC, and BtoE check in circuit on the transistor, and it
checks
OK,
but i never pulled it out of circuit.

Any Ideas?








"Q.E.D." <qed@verizon.net> wrote in message
news:f7tlivg8e0atun19067h7feu8qt0d94drm@4ax.com...
Looking for input into whether this June 1996 build TV is worth
having
repaired.

TV has worked great since purchase in 1996. Never got a great deal
of
use...maybe 10 hours a week on weekends to watch mainly movies on
DVD
or HBO. I figure less than 4000 hours total use. Set had been on
for
about 4 hours one day and the picture just went blank...like someone
turned it off. No warning of trouble before that...no picture fade
or
blooming, it just went dark. Sound still works OK.

The TV is long out of warranty but due to it's light use I was
thinking it might be worth repairing. Can anyone give me an idea
how
much would be a fair rate for a repairman to come out and diagnose
(I
live in Philadelphia, PA)? What's an average repair cost on a 35"
set? I realize the repair costs would be on top of the initial
estimate depending on what is wrong. On that note, are my TV's
symptoms indicative of a common problem? Based on my novice
research
I think it could be a high voltage problem.

The neighborhood repair guy went out of business about three years
ago. Choosing a repair service, I'm finding, is almost impossible
to
decide on blindly.

Any advice would be appreciated.

Thanks
Click to expand...
 
and thats about right, the datasheet to the scan IC says 5vp-p





"Bill Jr" <bill@nospam.usa2net.net> wrote in message
news:1IUWa.10985$K4.455734@twister.tampabay.rr.com...
IS the frequency of that square wave accurate?
IS the amplitude sufficient to turn on the horiz driver transistor?

Bill Jr


"Mike" <mbates14@fuse.net> wrote in message
news:syUWa.34437$hc.14352@fe3.columbus.rr.com...
P.S., the heatsink on the QX3201 stays cool.

the other 3 in the chopper circuit get regularly warm, thats the only
one
that stays cold.

could that be something? it junction tests good.




"Mike" <mbates14@fuse.net> wrote in message
news:LsUWa.34403$hc.14392@fe3.columbus.rr.com...
ok, I finally got to it.


All volteges are presant and none of the fuses are blown.

now, there was a pin problem.

Now, I set my scope up, and did some more testing on the tv,

the scan gen IS working. there is a square wave pulse on the pin 8.
there
is
a square wave pulse on the base of the horizontal driver transistor.
BUT,
there is NO DRIVE PULSE on the collector of the driver transistor. so,
i
guess its a bad transistor. I did some voltege measurements, and there
is
about 41VDC on the collector.

There is 158VDC B+ on the HOT.

I did a BtoC, and BtoE check in circuit on the transistor, and it
checks
OK,
but i never pulled it out of circuit.

Any Ideas?








"Q.E.D." <qed@verizon.net> wrote in message
news:f7tlivg8e0atun19067h7feu8qt0d94drm@4ax.com...
Looking for input into whether this June 1996 build TV is worth
having
repaired.

TV has worked great since purchase in 1996. Never got a great deal
of
use...maybe 10 hours a week on weekends to watch mainly movies on
DVD
or HBO. I figure less than 4000 hours total use. Set had been on
for
about 4 hours one day and the picture just went blank...like someone
turned it off. No warning of trouble before that...no picture fade
or
blooming, it just went dark. Sound still works OK.

The TV is long out of warranty but due to it's light use I was
thinking it might be worth repairing. Can anyone give me an idea
how
much would be a fair rate for a repairman to come out and diagnose
(I
live in Philadelphia, PA)? What's an average repair cost on a 35"
set? I realize the repair costs would be on top of the initial
estimate depending on what is wrong. On that note, are my TV's
symptoms indicative of a common problem? Based on my novice
research
I think it could be a high voltage problem.

The neighborhood repair guy went out of business about three years
ago. Choosing a repair service, I'm finding, is almost impossible
to
decide on blindly.

Any advice would be appreciated.

Thanks
Click to expand...
 
the only information i can tell you about the amplitude, is that the
waveform at the base is a little weaker than it is comming out of the IC,






"Bill Jr" <bill@nospam.usa2net.net> wrote in message
news:1IUWa.10985$K4.455734@twister.tampabay.rr.com...
IS the frequency of that square wave accurate?
IS the amplitude sufficient to turn on the horiz driver transistor?

Bill Jr


"Mike" <mbates14@fuse.net> wrote in message
news:syUWa.34437$hc.14352@fe3.columbus.rr.com...
P.S., the heatsink on the QX3201 stays cool.

the other 3 in the chopper circuit get regularly warm, thats the only
one
that stays cold.

could that be something? it junction tests good.




"Mike" <mbates14@fuse.net> wrote in message
news:LsUWa.34403$hc.14392@fe3.columbus.rr.com...
ok, I finally got to it.


All volteges are presant and none of the fuses are blown.

now, there was a pin problem.

Now, I set my scope up, and did some more testing on the tv,

the scan gen IS working. there is a square wave pulse on the pin 8.
there
is
a square wave pulse on the base of the horizontal driver transistor.
BUT,
there is NO DRIVE PULSE on the collector of the driver transistor. so,
i
guess its a bad transistor. I did some voltege measurements, and there
is
about 41VDC on the collector.

There is 158VDC B+ on the HOT.

I did a BtoC, and BtoE check in circuit on the transistor, and it
checks
OK,
but i never pulled it out of circuit.

Any Ideas?








"Q.E.D." <qed@verizon.net> wrote in message
news:f7tlivg8e0atun19067h7feu8qt0d94drm@4ax.com...
Looking for input into whether this June 1996 build TV is worth
having
repaired.

TV has worked great since purchase in 1996. Never got a great deal
of
use...maybe 10 hours a week on weekends to watch mainly movies on
DVD
or HBO. I figure less than 4000 hours total use. Set had been on
for
about 4 hours one day and the picture just went blank...like someone
turned it off. No warning of trouble before that...no picture fade
or
blooming, it just went dark. Sound still works OK.

The TV is long out of warranty but due to it's light use I was
thinking it might be worth repairing. Can anyone give me an idea
how
much would be a fair rate for a repairman to come out and diagnose
(I
live in Philadelphia, PA)? What's an average repair cost on a 35"
set? I realize the repair costs would be on top of the initial
estimate depending on what is wrong. On that note, are my TV's
symptoms indicative of a common problem? Based on my novice
research
I think it could be a high voltage problem.

The neighborhood repair guy went out of business about three years
ago. Choosing a repair service, I'm finding, is almost impossible
to
decide on blindly.

Any advice would be appreciated.

Thanks
Click to expand...
 
Why not just take the set to a TV shop and get a proffessional
to take a look and advise you , its pretty obvious you dont have the skills.

kip


yea im stupid, if thats the only way to find out whats wrong, because
other
approatches just arnt working.
Click to expand...
 
excuse me?
I work at a shop.



"john" <va3mm@niagara.com> wrote in message
news:newscache$mvc0jh$ba6$1@newsfeed.niagara.com...
Why not just take the set to a TV shop and get a proffessional
to take a look and advise you , its pretty obvious you dont have the
skills.

kip


yea im stupid, if thats the only way to find out whats wrong, because
other
approatches just arnt working.
Click to expand...
 
you may be right about not exciting the driver.

Here is what I have come up with.

There is 1.8VDC comming into the board through the cable comming from the
scan gen IC, and there is only .1VDC at the driver. and 41vdc at the
collector.

any ideas?

and there should be 5V p-p comming from the IC, but it might go through
resistors, dropping it down.







"Bill Jr" <bill@nospam.usa2net.net> wrote in message
news:1IUWa.10985$K4.455734@twister.tampabay.rr.com...
IS the frequency of that square wave accurate?
IS the amplitude sufficient to turn on the horiz driver transistor?

Bill Jr


"Mike" <mbates14@fuse.net> wrote in message
news:syUWa.34437$hc.14352@fe3.columbus.rr.com...
P.S., the heatsink on the QX3201 stays cool.

the other 3 in the chopper circuit get regularly warm, thats the only
one
that stays cold.

could that be something? it junction tests good.




"Mike" <mbates14@fuse.net> wrote in message
news:LsUWa.34403$hc.14392@fe3.columbus.rr.com...
ok, I finally got to it.


All volteges are presant and none of the fuses are blown.

now, there was a pin problem.

Now, I set my scope up, and did some more testing on the tv,

the scan gen IS working. there is a square wave pulse on the pin 8.
there
is
a square wave pulse on the base of the horizontal driver transistor.
BUT,
there is NO DRIVE PULSE on the collector of the driver transistor. so,
i
guess its a bad transistor. I did some voltege measurements, and there
is
about 41VDC on the collector.

There is 158VDC B+ on the HOT.

I did a BtoC, and BtoE check in circuit on the transistor, and it
checks
OK,
but i never pulled it out of circuit.

Any Ideas?








"Q.E.D." <qed@verizon.net> wrote in message
news:f7tlivg8e0atun19067h7feu8qt0d94drm@4ax.com...
Looking for input into whether this June 1996 build TV is worth
having
repaired.

TV has worked great since purchase in 1996. Never got a great deal
of
use...maybe 10 hours a week on weekends to watch mainly movies on
DVD
or HBO. I figure less than 4000 hours total use. Set had been on
for
about 4 hours one day and the picture just went blank...like someone
turned it off. No warning of trouble before that...no picture fade
or
blooming, it just went dark. Sound still works OK.

The TV is long out of warranty but due to it's light use I was
thinking it might be worth repairing. Can anyone give me an idea
how
much would be a fair rate for a repairman to come out and diagnose
(I
live in Philadelphia, PA)? What's an average repair cost on a 35"
set? I realize the repair costs would be on top of the initial
estimate depending on what is wrong. On that note, are my TV's
symptoms indicative of a common problem? Based on my novice
research
I think it could be a high voltage problem.

The neighborhood repair guy went out of business about three years
ago. Choosing a repair service, I'm finding, is almost impossible
to
decide on blindly.

Any advice would be appreciated.

Thanks
Click to expand...
 
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