My Amplifone monitor - last update

Last night I got my Amplifone monitor working. The boards had
lots of problems but with the help of people on this list I
managed to get them fixed.

Anyway, here's a summary of the problems:

Two HV boards: one looked good and I put a cap kit into it but
it was dead (very noisy, no action in the tube). The second one
had a jumper wire across the -24V regulator, I replace the regulator
and put a 50 ohm resistor where the jumper wire was. I also replaced
most of the electrolytic caps on the board. This board turned out
to be good as the trader told me.

Deflection board: Many fried resistors (R31, R30, R28, R35, R36). I
replaced all these resistors and put a Zannen kit into it (I also
replaced C13 which was burnt by R30). Fired it up and refired most
of the same resistors again. Further investigation showed that that
Q15 had shorted to the heat sink due to a problem with the insulator.
I then replaced all of Q4, Q5, Q14, and Q15. Fired it up again and
was getting spot killer. I turned up the brightness and was getting
Y deflection. Pulled the board again and found that F2 had blown. I
checked all the transistors on the X side (in-circuit) and found that
Q11 and Q12 were short across the emitter and collector in both
directions. I replaced them (after verifying they had problems after
removal). Replaced the fuse and all was well.

Getting this monitor working was a good feeling as this is my first
vector game. I used to play Star Wars at the U-Mass, Amherst, campus
center and dining commons in 84. Its great to now own a working game.

Now I need a tempest. If anyone has a fixer-uper for sale (I don't
need the boards), just a cab w/o boards and a dead monitor would be a
good start for me. I'm hoping to find something with good side art that
I could get delivered via forward air for around $200 (wishful thinking?).

Thanks again for all the help.

Dan R.
dras@sw.stratus.com
Received on Fri Nov 28 07:09:28 1997