RE: Gauntlet pcb woes

Good suggestions below - this is roughly what I did when fixing my board. I
dimly recall that you can boot the board up in test mode even with a bad
6502, so don't worry too much about the 6502 CPU at first.

Hot RAMs are a bad sign (of course :) - a set of the RAM chips are needed
even just to fire up the board in test mode. When this was happening on my
board, I pulled the hot RAM chips, and swapped the others around until the
board would come up in test. I don't recall seeing anything in the manual to
tell me which RAM and ROM chips are required for test, though.

Another note - when I had bad RAM chips, I was still able to get a video
signal (garbage) that would just reset every few seconds when the watchdog
timer tripped.

-atw

-----Original Message-----
From: owner-rasterlist@vectorlist.org
[mailto:owner-rasterlist@vectorlist.org]On Behalf Of Jess Askey
Sent: Thursday, October 16, 2003 11:14 PM
To: rasterlist@vectorlist.org
Subject: Re: RASTER: Gauntlet pcb woes

this is a good general starting process.

1. Verify DC voltages, the +12/15V controls the reset line usually on
Atari boards
2. Verify no AC ripple on the power supply (usually not an issue with
switching power supplies but sometimes)
3. Check for CPU clock signal (pulsing)
4. Check that Reset pin is high. If low, then check reset logic.
5. Pull all ROMs that are not required for self test to run (generally
noted in manual)
6. Start replacing all socketed chips on at a time
7. Replace all excessively hot IC's
8. Get out the schems!! :-)

Christopher Bedwell wrote:

>I got my hot hands on a gauntlet pcb - its not firing
>up at all, no sound - no picture..
>
>Suggestions for where I should start ?
>
>Some socketed rams ( I assume ) are getting hot, the
>processor is warm.. theres power getting in, the led's
>are firing up..
>
>- Chris.
>
>=====
>
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Received on Sat Oct 18 12:33:34 2003