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Adam Preble
 
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Default Magnavox FP5230 repair

Bill, I think you're my new messiah:

Bill S. wrote:
I wouldn't recommend trying to measure the current. You may damage
your meter or other parts of the board, or more likely the power
supply will current-limit and you won't get useful data anyway.
Instead measure collector to emitter resistance of Q906 (use low
Ohms range). I bet it's shorted, and if so it's almost always
caused by T900 being bad.


It's nice of them to label that one on the board. I measured a low
resistance between the collector and the emitter, and my multimeter
actually chirped when I tested for a short. It is hard to get the
probes in that space, since a capacitor is in the way, but I tried it
twice and got a short each time.

I was told flyback transformers are the common thing to go on
televisions in general. Are you saying this transistor, that fuse
resistor, and the transformer are likely the things to change?

Not the best tool for the job, but can be used in a pinch. If you
are not practiced in the art of desoldering, you might want to
experiment with some unimportant throwaway pc board until you can
remove large parts without peeling off traces. The flyback can
be especially frustrating, as it has a lot of large pins. You'll
need some solderwick or one of those solder-pullit things.


I know it goes OT, but what kind of iron do you recommend then? I've
done some desoldering, but my worst experience with it was desoldering
on perfboard, but I'd take out the rings sometimes. You'd bet I'd
practice before trying to pull off a big blob. That and the flyback
would kill me in the process of playing with it.

And let us know when you get to removing the HV wire from the old
flyback, it's a bit tricky too.


I see some stuff in the FAQ about it. I have to get myself a few high
watt, mega ohm resistors. I'm hoping if I leave it unplugged a few
days, it will only mildly kill me as oppose to completely free me. wink