RE: VECTOR: Aseroids tech question

Thanks.  I'll give it a shot.  Assuming I need a new DAC, anybody have one
for sale?  

-----Original Message-----
From: Matt J. McCullar [mailto:[email protected]]
Sent: Monday, November 29, 2004 7:10 PM
To: [email protected]
Subject: Re: VECTOR: Aseroids tech question


Hey all.  My Asteroids has developed a horizontal line across the screen
over which the objects "jump."  This also shows up on the test screen as
"stretching" in the cross-hatch pattern.  I read on an Asteroids
troubleshooting site that this may be related to a D/A converter.  Is this
an easy fix?  Are the parts readily available?  Thanks in advance for any
help.  

It could be a bad DAC, or a bad counter driving it, or a bad op-amp
following the DAC.  The DAC is by far the most expensive chip, and the
hardest to get replacements for.  If you're soldering-savvy, you can isolate
the problem by desoldering both DACs and swap them.  If this "invisible
line" changes axes (from X to Y), then you've nailed it.  Swapping the
op-amp chips works this way, too.