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View Full Version : How much RAM could possibly be bad in an old AST Six Pack Plus?



rittwage
July 13th, 2014, 12:20 PM
So how many 4264's could be bad on an old AST Six Pack Plus that won't
POST? I mean, once in a while a chip or two might fail, right?

See photo.

Bad power supply? Lightning strike from 1985? :)

-Pete

SpidersWeb
July 13th, 2014, 12:24 PM
What machine were you testing in?
Asking because 200ns might not be quick enough for a turbo XT or 286 etc

Stone
July 13th, 2014, 01:13 PM
They could all be bad

The board could be bad

If there are bad chips in bank 0 it might prevent the board from being recognized.

Are the switches correctly configured?

What Spider said.

rittwage
July 13th, 2014, 02:57 PM
It's a stock 5150.

After the first few came up bad, I got tired of waiting for the PC to finish post and give the error code, so I just took every chip off and tested them one by one in my C64. After replacing the ones that failed (2 tests to be sure) the board comes up fine, all 640k, and passes the diagnostics.

No telling how long the board sat in someone's garage. The RAM seemed to fail open since none of them got warm... Often when I see this RAM go bad in the past, they get hot (failed short). I remember being able to look at a board of chips on the Amiga and see the bad ones, because they would be discolored from the heat.

bobba84
July 13th, 2014, 04:51 PM
I had the same problem on my 5160 last week after 7 years in storage. 11 bad chips. I guess they're getting old.