"DogP" wrote in message
oups.com...
No rear projection techs out there? I ordered some 2SC5143's and got
them yesterday... I pulled the whole chassis out and noticed that
there's another 2SC5143, and it was blown too! It looks like one goes
to the flyback, one goes to the yokes. So, I pulled both and replaced
just one, hooked it up with a light bulb in series with the main power,
and it still blew :-( . I only bought 4 replacments, thinking I only
needed 1 _.

Any idea what I could check to see what's causing these to blow? I've
checked all of the large transistors and diodes that I could find, and
made sure that none of the large capacitors were shorted. I really
don't know what else I can check, or what the next step in
troubleshooting this is.

Thanks,
Pat


There are lots of us out here. Responses have more to do with whether
someone has much to contribute than whether we are here. You might get more
help if you post the model number in the subject line. Some of us don't
catch every thread from the start and I personally won't go digging up the
previous posts to see if you had the relevant info. Some Mitsubishi sets
have been known to have repeated HOT failures due to a bad coil. Not
knowing what set or chassis you have makes it impossible to search for
specific info.

In general, repeat failures in outputs in RPTV is not different from direct
view sets. Problems in the base circuit such as intermittent drive or
impedance problems or load problems such as a bad flyback or bad cap are
most likely. Typically with Mitsubishis the problems have been drive
related as opposed to load.

Apparently this is a set with separate HV and H outputs. If both are
blowing it seems pretty obvious to be looking to the drive circuits or the
power supply. Since the Mits sets are pretty unlikely to operate with
excessive B+, I'd be leaning to a h-drive problem.

Leonard