Re Sony KV32s20

C

Charlie East

Guest
Tried this thing one more time! Afret replacing the two transistors and
R607, also replaced the two .47 caps on the base of each thansistor. Could
not find any shorts on the P/s board, Replaced the H-out, Could not find any
shorts in the H section, Drive trans and transformer resoldered ok.Ckt check
good back to the Large IC.
Brought Voltage up slow, At 60 VAC B+ was 134VDC.
The Degause relay was cycling, Why? I havent hit pwr switch yet>At this
point Everything was running cool.All the other p/s volts were low, I
figured because I Was at 60VAC. Then I got brave and started cranking the
Volts up.The degause relay stopped cycling, and the B+ dropped to 85 volts,
then it all blew again., What is going first, the H-out or the p/s? Does the
hroz come up before the power switch is turned on? why? I thought I could
have B+ To the h-out and nothing would happen until the power switch was
turned on.
Boy , have I been going to school on this bugger, and its eating my lunch
and dinner
Charlie
ceast@bellsouth.net
 
Tv tv failed in the on position, in which case as soon as the cpu sees
standby power it will try and turn on the tv set.

Whenever checking these the first time after an smps repair the HOT should
always be out of circuit and the b+ line to the flyback taken to ground
through a 60w light bulb.

The SMPS will regulate in standby mode with as low as 40vac.

I am pretty certain that if there is not a h-drive issue, the failure is
either the flyback or the crt. Both are very high failure items on that
specific model.

David

Charlie East <ceast@bellsouth.net> wrote in message
news:fwRAb.3615$IF.249@bignews4.bellsouth.net...
Tried this thing one more time! Afret replacing the two transistors and
R607, also replaced the two .47 caps on the base of each thansistor. Could
not find any shorts on the P/s board, Replaced the H-out, Could not find
any
shorts in the H section, Drive trans and transformer resoldered ok.Ckt
check
good back to the Large IC.
Brought Voltage up slow, At 60 VAC B+ was 134VDC.
The Degause relay was cycling, Why? I havent hit pwr switch yet>At this
point Everything was running cool.All the other p/s volts were low, I
figured because I Was at 60VAC. Then I got brave and started cranking the
Volts up.The degause relay stopped cycling, and the B+ dropped to 85
volts,
then it all blew again., What is going first, the H-out or the p/s? Does
the
hroz come up before the power switch is turned on? why? I thought I could
have B+ To the h-out and nothing would happen until the power switch was
turned on.
Boy , have I been going to school on this bugger, and its eating my lunch
and dinner
Charlie
ceast@bellsouth.net
Click to expand...
 
A few ideas...

You can put a 60 W lamp in series with the power supply as a ballast. This
should prevent over-current.

Change all the blown parts. Do not solder back the new horiz output
transistor yet. Put the scope on the base connection of the horiz output,
and turn on the set without the horiz output transistor soldered in yet.
You should see the start-up pulses for about 100 ms.

If you have the start-up pulses, change the flyback transformer, and put
back the transistor. With the 60 Watt lamp in series with the supply, you
can start the set. If there are continuous pulses on the base of the horiz
output transistor, you can then bypass the lamp. You should see a continuous
train of drive pulses on the base of the horiz output transistor, and also
be able to measure the secondary output voltages on the flyback. The may be
a bit low, because of the current limiting of the series lamp.

I have had many instances of the flyback being defective, causing the horiz
outputs to blow, and also had shorted CRT's cause this as well.


--

Greetings,

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


"Charlie East" <ceast@bellsouth.net> wrote in message
news:fwRAb.3615$IF.249@bignews4.bellsouth.net...
Tried this thing one more time! Afret replacing the two transistors and
R607, also replaced the two .47 caps on the base of each thansistor. Could
not find any shorts on the P/s board, Replaced the H-out, Could not find any
shorts in the H section, Drive trans and transformer resoldered ok.Ckt check
good back to the Large IC.
Brought Voltage up slow, At 60 VAC B+ was 134VDC.
The Degause relay was cycling, Why? I havent hit pwr switch yet>At this
point Everything was running cool.All the other p/s volts were low, I
figured because I Was at 60VAC. Then I got brave and started cranking the
Volts up.The degause relay stopped cycling, and the B+ dropped to 85 volts,
then it all blew again., What is going first, the H-out or the p/s? Does the
hroz come up before the power switch is turned on? why? I thought I could
have B+ To the h-out and nothing would happen until the power switch was
turned on.
Boy , have I been going to school on this bugger, and its eating my lunch
and dinner
Charlie
ceast@bellsouth.net
 
Usually Sony,s after the famous blow up,s
are in the ON mode so the set when plugged
in will start to come on.Look for open resistors
off the Black VDR I think 68ohm may be 6.8ohm.
Also resolder Hor Drive Transistor and all in that area.

kip

--
"Watch the return E-Mail addy its false"
"Charlie East" <ceast@bellsouth.net> wrote in message
news:fwRAb.3615$IF.249@bignews4.bellsouth.net...
Tried this thing one more time! Afret replacing the two transistors and
R607, also replaced the two .47 caps on the base of each thansistor. Could
not find any shorts on the P/s board, Replaced the H-out, Could not find
any
shorts in the H section, Drive trans and transformer resoldered ok.Ckt
check
good back to the Large IC.
Brought Voltage up slow, At 60 VAC B+ was 134VDC.
The Degause relay was cycling, Why? I havent hit pwr switch yet>At this
point Everything was running cool.All the other p/s volts were low, I
figured because I Was at 60VAC. Then I got brave and started cranking the
Volts up.The degause relay stopped cycling, and the B+ dropped to 85
volts,
then it all blew again., What is going first, the H-out or the p/s? Does
the
hroz come up before the power switch is turned on? why? I thought I could
have B+ To the h-out and nothing would happen until the power switch was
turned on.
Boy , have I been going to school on this bugger, and its eating my lunch
and dinner
Charlie
ceast@bellsouth.net
Click to expand...
 
Also be very careful not to insert those reg,s backwards.
Very easy to do if you are not paying attention.
Just a thought.

kip



--
"Watch the return E-Mail addy its false"
"Charlie East" <ceast@bellsouth.net> wrote in message
news:fwRAb.3615$IF.249@bignews4.bellsouth.net...
Tried this thing one more time! Afret replacing the two transistors and
R607, also replaced the two .47 caps on the base of each thansistor. Could
not find any shorts on the P/s board, Replaced the H-out, Could not find
any
shorts in the H section, Drive trans and transformer resoldered ok.Ckt
check
good back to the Large IC.
Brought Voltage up slow, At 60 VAC B+ was 134VDC.
The Degause relay was cycling, Why? I havent hit pwr switch yet>At this
point Everything was running cool.All the other p/s volts were low, I
figured because I Was at 60VAC. Then I got brave and started cranking the
Volts up.The degause relay stopped cycling, and the B+ dropped to 85
volts,
then it all blew again., What is going first, the H-out or the p/s? Does
the
hroz come up before the power switch is turned on? why? I thought I could
have B+ To the h-out and nothing would happen until the power switch was
turned on.
Boy , have I been going to school on this bugger, and its eating my lunch
and dinner
Charlie
ceast@bellsouth.net
Click to expand...
 
Ok, This is what I done to it today. Put a 40W light blub in place of
R607.Started bringing it up slow, The Degause relay statred cycling, Came on
up with it and the relay stopped cycling.At full voltage the B+ in 134.8,
33V is 30.7, 22.8V is 21.6, 10.3 is 8.9,9V is 8.4, 5v is 4.9..
Scope the base of H- out(transistor still out of the circuit)Hit pwr sw and
got pulses on the base. However they stay there until I hit pwr sw again.
They are real ugly compared to the sams. but then I guess they were taken
with a fully operating set... I guess the next step is to replace the
Flyback. But what about the pulses, should they only be there momentarily,
or stay there until the power is turned off? Also I guess I should move the
light bulb to the 134V line to check after replacing the flyback?

Thanks
Charlie
ceast@bellsouth.net

"David" <dkuhajda@locl.net.spam> wrote in message
news:3fd414c0@news.greennet.net...
Tv tv failed in the on position, in which case as soon as the cpu sees
standby power it will try and turn on the tv set.

Whenever checking these the first time after an smps repair the HOT should
always be out of circuit and the b+ line to the flyback taken to ground
through a 60w light bulb.

The SMPS will regulate in standby mode with as low as 40vac.

I am pretty certain that if there is not a h-drive issue, the failure is
either the flyback or the crt. Both are very high failure items on that
specific model.

David

Charlie East <ceast@bellsouth.net> wrote in message
news:fwRAb.3615$IF.249@bignews4.bellsouth.net...
Tried this thing one more time! Afret replacing the two transistors and
R607, also replaced the two .47 caps on the base of each thansistor.
Could
not find any shorts on the P/s board, Replaced the H-out, Could not find
any
shorts in the H section, Drive trans and transformer resoldered ok.Ckt
check
good back to the Large IC.
Brought Voltage up slow, At 60 VAC B+ was 134VDC.
The Degause relay was cycling, Why? I havent hit pwr switch yet>At this
point Everything was running cool.All the other p/s volts were low, I
figured because I Was at 60VAC. Then I got brave and started cranking
the
Volts up.The degause relay stopped cycling, and the B+ dropped to 85
volts,
then it all blew again., What is going first, the H-out or the p/s? Does
the
hroz come up before the power switch is turned on? why? I thought I
could
have B+ To the h-out and nothing would happen until the power switch was
turned on.
Boy , have I been going to school on this bugger, and its eating my
lunch
and dinner
Charlie
ceast@bellsouth.net
Click to expand...
 
Anyone familiar with ACME sales? They list this Flyback for $8.95

charlie

"Charlie East" <ceast@bellsouth.net> wrote in message
news:xmbBb.2599$4t2.102@bignews4.bellsouth.net...
Ok, This is what I done to it today. Put a 40W light blub in place of
R607.Started bringing it up slow, The Degause relay statred cycling, Came
on
up with it and the relay stopped cycling.At full voltage the B+ in 134.8,
33V is 30.7, 22.8V is 21.6, 10.3 is 8.9,9V is 8.4, 5v is 4.9..
Scope the base of H- out(transistor still out of the circuit)Hit pwr sw
and
got pulses on the base. However they stay there until I hit pwr sw again.
They are real ugly compared to the sams. but then I guess they were taken
with a fully operating set... I guess the next step is to replace the
Flyback. But what about the pulses, should they only be there momentarily,
or stay there until the power is turned off? Also I guess I should move
the
light bulb to the 134V line to check after replacing the flyback?

Thanks
Charlie
ceast@bellsouth.net

"David" <dkuhajda@locl.net.spam> wrote in message
news:3fd414c0@news.greennet.net...
Tv tv failed in the on position, in which case as soon as the cpu sees
standby power it will try and turn on the tv set.

Whenever checking these the first time after an smps repair the HOT
should
always be out of circuit and the b+ line to the flyback taken to ground
through a 60w light bulb.

The SMPS will regulate in standby mode with as low as 40vac.

I am pretty certain that if there is not a h-drive issue, the failure is
either the flyback or the crt. Both are very high failure items on that
specific model.

David

Charlie East <ceast@bellsouth.net> wrote in message
news:fwRAb.3615$IF.249@bignews4.bellsouth.net...
Tried this thing one more time! Afret replacing the two transistors
and
R607, also replaced the two .47 caps on the base of each thansistor.
Could
not find any shorts on the P/s board, Replaced the H-out, Could not
find
any
shorts in the H section, Drive trans and transformer resoldered ok.Ckt
check
good back to the Large IC.
Brought Voltage up slow, At 60 VAC B+ was 134VDC.
The Degause relay was cycling, Why? I havent hit pwr switch yet>At
this
point Everything was running cool.All the other p/s volts were low, I
figured because I Was at 60VAC. Then I got brave and started cranking
the
Volts up.The degause relay stopped cycling, and the B+ dropped to 85
volts,
then it all blew again., What is going first, the H-out or the p/s?
Does
the
hroz come up before the power switch is turned on? why? I thought I
could
have B+ To the h-out and nothing would happen until the power switch
was
turned on.
Boy , have I been going to school on this bugger, and its eating my
lunch
and dinner
Charlie
ceast@bellsouth.net
Click to expand...
 
What about the resistors off the VDR,s did you check those.

kip

--
"Watch the return E-Mail addy its false"
"Charlie East" <ceast@bellsouth.net> wrote in message
news:qHbBb.3443$Yt2.2012@bignews3.bellsouth.net...
Anyone familiar with ACME sales? They list this Flyback for $8.95

charlie

"Charlie East" <ceast@bellsouth.net> wrote in message
news:xmbBb.2599$4t2.102@bignews4.bellsouth.net...
Ok, This is what I done to it today. Put a 40W light blub in place of
R607.Started bringing it up slow, The Degause relay statred cycling,
Came
on
up with it and the relay stopped cycling.At full voltage the B+ in
134.8,
33V is 30.7, 22.8V is 21.6, 10.3 is 8.9,9V is 8.4, 5v is 4.9..
Scope the base of H- out(transistor still out of the circuit)Hit pwr sw
and
got pulses on the base. However they stay there until I hit pwr sw
again.
They are real ugly compared to the sams. but then I guess they were
taken
with a fully operating set... I guess the next step is to replace the
Flyback. But what about the pulses, should they only be there
momentarily,
or stay there until the power is turned off? Also I guess I should move
the
light bulb to the 134V line to check after replacing the flyback?

Thanks
Charlie
ceast@bellsouth.net

"David" <dkuhajda@locl.net.spam> wrote in message
news:3fd414c0@news.greennet.net...
Tv tv failed in the on position, in which case as soon as the cpu sees
standby power it will try and turn on the tv set.

Whenever checking these the first time after an smps repair the HOT
should
always be out of circuit and the b+ line to the flyback taken to
ground
through a 60w light bulb.

The SMPS will regulate in standby mode with as low as 40vac.

I am pretty certain that if there is not a h-drive issue, the failure
is
either the flyback or the crt. Both are very high failure items on
that
specific model.

David

Charlie East <ceast@bellsouth.net> wrote in message
news:fwRAb.3615$IF.249@bignews4.bellsouth.net...
Tried this thing one more time! Afret replacing the two transistors
and
R607, also replaced the two .47 caps on the base of each thansistor.
Could
not find any shorts on the P/s board, Replaced the H-out, Could not
find
any
shorts in the H section, Drive trans and transformer resoldered
ok.Ckt
check
good back to the Large IC.
Brought Voltage up slow, At 60 VAC B+ was 134VDC.
The Degause relay was cycling, Why? I havent hit pwr switch yet>At
this
point Everything was running cool.All the other p/s volts were low,
I
figured because I Was at 60VAC. Then I got brave and started
cranking
the
Volts up.The degause relay stopped cycling, and the B+ dropped to 85
volts,
then it all blew again., What is going first, the H-out or the p/s?
Does
the
hroz come up before the power switch is turned on? why? I thought I
could
have B+ To the h-out and nothing would happen until the power switch
was
turned on.
Boy , have I been going to school on this bugger, and its eating my
lunch
and dinner
Charlie
ceast@bellsouth.net
Click to expand...
 
Replacing the Flyback fixed the set
Thanks for the replys
Charlie

"Charlie East" <ceast@bellsouth.net> wrote in message
news:fwRAb.3615$IF.249@bignews4.bellsouth.net...
Tried this thing one more time! Afret replacing the two transistors and
R607, also replaced the two .47 caps on the base of each thansistor. Could
not find any shorts on the P/s board, Replaced the H-out, Could not find
any
shorts in the H section, Drive trans and transformer resoldered ok.Ckt
check
good back to the Large IC.
Brought Voltage up slow, At 60 VAC B+ was 134VDC.
The Degause relay was cycling, Why? I havent hit pwr switch yet>At this
point Everything was running cool.All the other p/s volts were low, I
figured because I Was at 60VAC. Then I got brave and started cranking the
Volts up.The degause relay stopped cycling, and the B+ dropped to 85
volts,
then it all blew again., What is going first, the H-out or the p/s? Does
the
hroz come up before the power switch is turned on? why? I thought I could
have B+ To the h-out and nothing would happen until the power switch was
turned on.
Boy , have I been going to school on this bugger, and its eating my lunch
and dinner
Charlie
ceast@bellsouth.net
Click to expand...
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top