Re: Philips GR2.4 TV Chassis

Thank's both for your comments much apreciated, a little bit of
information goes a long way.

Firstly, the fault does not appear to match exactly any of those
commonly found on chassis in databases in the database links posted.

Hower, looking at this circuit again with reference to the cited
comments on pin 9 being low this now becomes quite logical and will
now do some testing based on this. The capacitor faults also cited
will also be investigated but it should be said that some previous
testing with capacitance meter and DVM resister checks have yielded no
out of tolerance electrolytics or o/c ressitors thus far in S.M.P.S..
However, not all electrolytics were thoughly checked so will re-do
more comprehensive tests in the PSU.

Will post up further findings based on pin 9 testing of the TDA8385 IC
for general interest.

Once again, many thanks for helpful comments.

Daz

On Mon, 12 Jun 2006 07:30:20 +1000, Franc Zabkar
<fzabkar@xxxxxxxxxxxxxxxxx> wrote:


I'm not familiar with your chassis, but I once saw a similar problem
in a Sony set. The culprit was a dried out B+ filter capacitor. Other
generic possibilities are the small electros on the primary side, or
open resistors at the feedback input to the SMPS chip. AFAICS, when
the TDA8385 is regulating properly, the voltage on pin 9 should be
equal to its internal reference voltage, namely 2.5V. If the input at
pin 9 is low, then I'd check that the IC's output at pin 2 is low.
This would at least tell you that the IC is trying to do its job.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

.

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