TECH: Asteroids XY monitor fault

[retroshaun]

[ukvac] TECH: Asteroids XY monitor fault
Hi..
Ongoing problem with my Asteroids (over a year now and counting... only
getting some "progress" this holiday season!)...
Finally got a board which is "working" (I am told it works fine after a
fellow list-member kindly repaired it for me), and now I am back to my
old problem...

The monitor is only displaying one "pixel" (if you will!) of image in
the Y axis, the X axis is being drawn as normal. So basically you can
see all the attract mode flying around, but squished down to one screen
line high (drawn straight across the dead centre of the screen).

Can anyone help me? Its starting to get really frustrating, and I dont
really know what I'm doing! I have replaced the monoitor board (with one
which appeared to be dead altogether)... is it likely to be the monoitor
board at fault, the monitor, or something else?

Thanks guys!
Shaun

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[P-Man]

Re: [ukvac] TECH: Asteroids XY monitor fault
either you are missing one of the XY signals (either X or Y, i can't
remember which) going from the board to the monitor, so it could be a wiring
problem..

or it could be the chassis deflection transistors, or another part of the x
or y sections of your monitor.

first step, measure the continuity between the board and the monitor
(measure ON the monitor chassis) this will ensure you're getting the XY
signals right thru all the wiring/connectors

Andy