Re: Asteroids Deluxe board broblems.

If you have a scope, check the output of the DACs. Should show NO SIGNAL.
These are CURRENT devices, the first op amp (current to voltage convertor)
after should show the signal on it's output and feedback loop only. If you
see a signal on the DAC replace the OP amp first. Next is the signal (have
the board in SelfTest) more or less balanced across the zero-volt line of
the scope? If so, then go to the output of the last op amp, is it balanced?
If not, check inputs. If balanced replace output op amp. I assume you have
verified the +15/-15/+8/-8 of course...

John :-#)#

At 12:17 PM 6/1/00, James G Watt wrote:
>In article <4.2.2.20000526084959.01a89010@pop.mindspring.com>, Jon
>Raiford <raiford@mindspring.com> writes
> >This sounds all too familiar..
>
>Thanks. Following that I fixed some problems in the vsm and my board now
>runs without tripping the watchdog... but now I'm getting a steady
>6.5volts on the y-out and a steady -13.2volts on the x-out :-/
>
>I'm told "it might be a prob with the position counters and that kinda
>area or the dacs :(". Any more advice?
>--
>James G Watt
>
>http://www.kinetic-arts.demon.co.uk
>Part of the Video Arcade Game Collectors WebRing.
>
>You are in a maze of twisty little passages, all alike.
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Received on Thu Jun 1 17:57:12 2000