On Mon, 01 Aug 2005 06:59:12 GMT, Alan Stevens
put finger to keyboard and
composed:


I would appriciate any advice I could get on my next step with
troubleshooting a Sansui TVM2500C "Version A" 25-inch television set.

snip

When first powered up,
the screen lights up with normal empty-channel snow even though a
station should be present on that channel, there is no volume, the
channel up/down buttons work properly (the numbers change on the
on-screen display, anyway) but the volume up/down buttons do not - one
volume button causes the channel to change and the other doesn't do
anything.

If the volume control works correctly via the remote, then I would
suspect a problem with the uP's key matrix. I have seen this kind of
behaviour (in other TVs) when water has got into the set. IME it's the
glass IN4148-type signal diodes that are usually affected.


- Franc Zabkar
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