[TechAssist] Re: Sony KV32XBR96S (repeated audio amp IC failure)
- From: "Damon" <damon101@xxxxxxxxxxxxxx>
- To: <techassist@xxxxxxxxxxxxx>
- Date: Fri, 23 Jul 2004 07:28:27 -0500
That's the G board mounted vertically on the left side of the TV correct??
I hope you have schematics, because if this info is correct, Sony built the
primary SMPS with 2 sets of 'matched pair' outputs that operated in parallel
with each other.....I had one that kept blowing the pairs one at a time
until all were replaced at the same time......>>>and there was a tiny VDR
located near the drive transformer that was killing them.<<< I've only seen
that design once, in their very first TVs that used q602/q603.
The relay powering up the SMPS....chattering is most likely due to dried out
cap or high resistance in the supply for that relay.......if its not related
to OCP shutdown that is....The unloaded SMPS/Variac test you posted is the
Sony defacto test used by them.....good place to start.
Damon Brunger
----- Original Message -----
From: "Gemini Computer & TV" <geminitv@xxxxxxxxxxx>
To: <techassist@xxxxxxxxxxxxx>
Sent: Thursday, July 22, 2004 10:56 AM
Subject: [TechAssist] Re: Sony KV32XBR96S (repeated audio amp IC failure)
| Thanks. I wouldn't wish this one on any of you. You are all aware that I
am
| at least vaguely familiar with Sony power supplies. See this response from
| another forum but I don't think he is talking about the same power supply
as
| there are no mylar caps or fuse resistor in this one:
|
| Always replace Q601,602, both VDRs, all the diodes 4 in some, 8 in others,
| and the two mylar caps in series with the transformer primary, and the
fuse
| resistor. Disconnect the HOT , and plug the set into a variac set to 30 v
| AC. With a scope, verify a 50 khz sine wave at the transformer primary.
With
| a DC meter, measure the B+ at the fuse resistor. DC at Q602 (E or C memory
| fails) should be EXACTLY 1/2 the B+ Dc voltage. If it is not, other parts
in
| the Q601,602 circuit, especially the transformer are bad. If it is exact,
| reconnect the HOT and try the set with series lamp. No shortcuts!
|
| Bob Waterman, CET® #RI-28
| Master Technician License #9109
| Service Manager / Parts Manager
| Gemini Computer, TV, & Security Alarms
| (508)695-7302
| (508)695-7769 FAX
| geminitv@xxxxxxxxxxx
| geminitv@xxxxxxx
| www.geminicomputertvsecurityalarms.com
|
|
| ----- Original Message -----
| From: "Jim Myers" <jr.myers@xxxxxxxxxxx>
| To: <techassist@xxxxxxxxxxxxx>
| Sent: Thursday, July 22, 2004 11:38 AM
| Subject: [TechAssist] Re: Sony KV32XBR96S (repeated audio amp IC failure)
|
|
| > A couple of tips mention Q605 on the G board, you probably should look
| > at that if you haven't already. Good luck on this one, sounds like a job
| > none of us would want to be stuck with.
| >
|
****************************************************************************
| ***************************************
| > Since 1972
| > Jim Myers
| > Telrad Electronics
| > Fort Wayne, Indiana
| >
| >
| > Gemini Computer & TV wrote:
| > > Update! Besides the audio amp IC (IC1401) being blown again and
| replacing it
| > > along with D1409, D1410, D1411, and C1407, I have found the following
| > > defective components in the power supply and replaced them:
| > >
| > > Q603
| > > Q604
| > > VDR602
| > > R623
| > >
| > > After replacing these and every electrolytic on the "G" (power supply)
| > > board, when plugging in the set the relay starts to chatter repeatedly
| and
| > > Q603 and Q604 get very hot immediately and shortly thereafter short
| again
| > > (even with connector G5 disconneted for audio amp B+). this time
| however,
| > > R623 remains normal. I can't seem to locate why and I am spending far
| too
| > > much time on this set and the customer is very anxious to get it back.
I
| had
| > > previously replaced C662 and C668 but as I indicated, all
electrolytics
| have
| > > been replaced (again for some of them). Anyone have some sugestions?
| > >
| > > Bob Waterman, CET® #RI-28
| > > Master Technician License #9109
| > > Service Manager / Parts Manager
| > > Gemini Computer, TV, & Security Alarms
| > > (508)695-7302
| > > (508)695-7769 FAX
| > > geminitv@xxxxxxxxxxx
| > > geminitv@xxxxxxx
| > > www.geminicomputertvsecurityalarms.com
| > >
| > >
| > > ----- Original Message -----
| > > From: "Gemini Computer & TV" <geminitv@xxxxxxxxxxx>
| > > To: "Techassist" <techassist@xxxxxxxxxxxxx>
| > > Sent: Monday, June 28, 2004 8:24 AM
| > > Subject: [TechAssist] Sony KV32XBR96S (repeated audio amp IC failure)
| > >
| > >
| > >
| > >>I have a customer (who is an electronics engineer) with a Sony
| KV32XBR96S
| > >>who brought in his set (as he lives outside my in-home service area)
| back
| > >
| > > in
| > >
| > >>January for a dead set condition. I had found the front audio amp IC
| > >>(IC1401) blown with a hole in it. There were also other damaged
| components
| > >>as well that were replaced with Sony originals. Here is a list of
those
| > >>parts:
| > >>IC1401
| > >>IC1501
| > >>D1409
| > >>D1410
| > >>D1411
| > >>C661
| > >>C662
| > >>C668
| > >>VDR602
| > >>R623
| > >>
| > >>Everything was fine until the beginning of June when the customer once
| > >
| > > again
| > >
| > >>brought it in for a dead set condition again. This time I found and
| > >
| > > replaced
| > >
| > >>the following components with Sony originals:
| > >>IC1401
| > >>D1409
| > >>D1410
| > >>D1411
| > >>
| > >>I completed the repair on Friday, 06/18/2004 and let the set run
| > >
| > > continously
| > >
| > >>around the clock until he picked it up on Thursday, 06/24/2004. I had
| > >>informed the customer that IC1401 once again had a hole blown in it
and
| > >
| > > had
| > >
| > >>him check the external speaker wire connections to make sure that none
| had
| > >>excessive length of exposed bare copper at either end when he returned
| > >
| > > home.
| > >
| > >>The set ran great Thursday, Friday, and part of Saturday but then the
| > >>customer states he lost audio for about 15 minutes, then lost the
| picture,
| > >>smelled burning, and the set returned to it's same old dead set
| condition.
| > >
| > > I
| > >
| > >>just got off the phone with him and explained that it sounds like that
| > >>IC1401 may have blown again but I am at a loss to explain the reason
for
| a
| > >>repeated failure and that I would pose this question to my fellow
| > >>technicians on the various email forums to which I am a member. So now
| let
| > >>me request your collective ideas!
| > >>
| > >>Bob Waterman, CET® #RI-28
| > >>Master Technician License #9109
| > >>Service Manager / Parts Manager
| > >>Gemini Computer, TV, & Security Alarms
| > >>(508)695-7302
| > >>(508)695-7769 FAX
| > >>geminitv@xxxxxxxxxxx
| > >>geminitv@xxxxxxx
| > >>www.geminicomputertvsecurityalarms.com
| > >>
| > >>
| > >>
| >
|
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| > >
| > >
| > >
| > >
| >
|
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