Looking for Zenith SMPS rebuild kit

[Rua Dumas]

Trying to find a rebuild kit for a zenith Z32X31D switching mode power
supply. Any information would be greatly appreciated.

TIA, August

 

[Sofie]

Rua Dumas / August
Most rebuild kits include:

fuse
bridge rectifier
zener diode(s)
power switching transistor
opto-isolator
misc small signal transistors
electrolytic capacitors

As you probably know from reading past postings on this newsgroup, the most
likely failure items in most SMPS circuitry are faulty high ESR electrolytic
capacitors, shorted diodes and shorted power switching transistor.....
obviously the other parts can fail too and should be checked.
Many shop techs don't bother with the time consuming wholesale changeout of
all the parts found in a rebuild kit. They usually conduct component tests
and only replace what is necessary. Because of this, if you have the
necessary repair experience, electronics knowledge and proper test equipment
you may not want to bother with the rebuild kit and just perform component
level troubleshooting.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
--------------------------



"Rua Dumas" <bergfeld-a-l@worldnet.att.net> wrote in message
news:qJJLb.7154$6y6.204037@bgtnsc05-news.ops.worldnet.att.net...

Trying to find a rebuild kit for a zenith Z32X31D switching mode power
supply. Any information would be greatly appreciated.

TIA, August

 

[Jason D.]

On Fri, 9 Jan 2004 19:08:41 -0800, "Sofie" <sofie@olypen.com> wrote:

Rua Dumas / August
Most rebuild kits include:

fuse
bridge rectifier
zener diode(s)
power switching transistor
opto-isolator
misc small signal transistors
electrolytic capacitors


Many shop techs don't bother with the time consuming wholesale changeout of
all the parts found in a rebuild kit. They usually conduct component tests
and only replace what is necessary. Because of this, if you have the
necessary repair experience, electronics knowledge and proper test equipment
you may not want to bother with the rebuild kit and just perform component
level troubleshooting.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
--------------------------

32" is worth getting whole kit changed wholesale. BUT, double check
that CRT is not chassis fryer. This will fry SMPS if the CRT is
leaking too much or G1 short, also bad CRT usually takes out a small
transistor buffer, there's three for red, blue and green that is next
to jungle IC. Sometimes CRT get too much causes CRT driver transistor
to run hot and short out forcing me to repair the repeat unit, put on
heatsink for it. Helped much.

Today I finally came across a 27" zenith with dud vertical IC.
Replaced that vertical IC, found out that set has good CRT and SMPS
was running much cooler. In past with other zenith sets in this 25/27
sizes even 32" had SMPS heatsink running almost at meltdown because of
lousy CRT leaking too much pulling on whole chassis. I did rejuvenate
the zenith CRTs too and still doesn't do the job. Did the SMPS
rebuild & checked caps and replaced key caps that has too much ESR FYI
and they still run red hot.

I had a bunch of that zenith TV sets with blown SMPSes about 1 and
half years ago just on SMPS rebuild since then, finally died down to
quiet.

Cheers,

Wizard