Re: SMPS help needed - Philips VCR

Early days yet but it would appear as though both Q003 (infinite
resistance both ways across one junction) and D015 (short circuit) are
both dead. So a good call on both counts.

Unfortunately I can't get a replacement diode or a close transistor
match until tomorrow so it'll be after the weekend before I find out
what else has blown.

Aside from experience, what else led you guys to the above
conclusions? Why do the symptoms point at these components?

Thanks,
Andy

On Aug 7, 1:44 pm, s...@xxxxxxxxxxxxxx (Samuel M. Goldwasser) wrote:
Franc Zabkar <fzab...@xxxxxxxxxxxxxxxxx> writes:
On 06 Aug 2008 19:16:33 -0400, s...@xxxxxxxxxxxxxx (Samuel M.
Goldwasser) put finger to keyboard and composed:

While you're at it, it would be worthwhile to check the electrolytic
caps for ESR and uF. If the zener is shorted, the cause may be bad
caps.

Thanks for the followup.

I just remembered that I've seen faults in Sharp VCRs (Philips VCRs
are often rebadged Sharps) where the zener isn't actually shorted, but
is protecting the outputs from an overvoltage caused by a small
electrolytic cap on the primary side of the supply. In this case I'd
change CO11 just for good measure.

Good idea to change them all if you find one that is marginal or bad!

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