TECH: Amplifone Q's

        It was my first weekend in my new house (that I wasn't
moving stuff in) so I was able to fix/try to fix a few games.

        The good news: My Star Wars now works perfectly (..and
there was much rejoycing...yea, yea)

        The bad news: The Amplifone in my Quantum is really sick.
I replaced the following on the HV board: HV transformer, BU406D,
7824, 7924, electrolytic caps. I still get NO HV whatsoever. The
deflection board seems good (I can hear clatter in the neck, AND the
spot killer seems to be operating normally -- a little pulse when
the game gets turned on, but then it goes off)

        The wierd part of it all is that the tube NEVER sparks,
crackles, etc when I discharge it to disconnect the HV connection.
It never sparks when I discharge it to re-connect the HV connection.
In every monitor I've worked on, I've always been able to get some
kind of spark/snap/whatever when I went to discharge it (even when it
had just been sitting there, with the HV connection disconnected for
a while....There also NO glow from the back of the neck (I even looked for
thse sparks and glow at night.) Does this sound like a bad tube? There
is no high-pitched whine from the HV transformer but there isn't from the
WG HV transformers either, so I don't know if that is normal or not.

        I haven't checked voltages on the HV board yet (Remember, it
was night time, and poking around on a HV board in the dark, while
the monitor is on, is not my idea of a good time!) but will do that
today.

        Any help would be appreciated...Thanks in advance!

Joe

BTW: Has anybody tried using the NTE cross for the SK part that is
listed on Jess's page as a replacement for the HV diode in the GO-5?
I don't think there is a place in town that sells SK parts, and I'd
rather not mail order (I want my diode now, NOW!)

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Joseph J. Welser jwelser@ccwf.cc.utexas.edu
Design Engineer -- Crystal Semiconductor Corporation
Ph.D. Student in E.E. -- University of Texas at Austin
Work: jwelser_at_crystal.cirrus.com http://www.crystal.com
P.O. Box 17847; Austin, TX 78760
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Received on Mon Oct 6 08:23:13 1997