Stargate RAM Errors - Is RAM IC temp any indicator?

Done with the APAR kits and all voltages good, switcher in the trash. Now to put some molex connectors back on the power feeds to all the boards. Probably start replacing some other IDC connectors with crimps while I'm at it.
 
Contrary to what some people say, not all IDC's are bad. (I can't speak for all games, but the ones on Atari games tend to rarely give issues.)

However the point is, connectors aren't magic. If a connector is bad, you should be able to MEASURE it, to show that it is. (Measure, Find, Replace.)

Shotgunning connectors isn't an 'upgrade', and may actually cause MORE issues, if they aren't a problem to begin with.

Keep things original unless you can MEASURE that they're a problem.
 
Does the RAM test just go sequentially from 11 to 38? I know 113 doesn't necessarily mean RAM 13 is bad but I moved it to 23 and the error moved to 23. Moved it to 38 and the error is at 38. Any other thoughts before I order some RAM? Anything else I should rule out first?
 
Just for kicks i did scrub it with a fiberglass pencil and hit it with deoxit, but no change.
 
Contrary to what some people say, not all IDC's are bad. (I can't speak for all games, but the ones on Atari games tend to rarely give issues.)

However the point is, connectors aren't magic. If a connector is bad, you should be able to MEASURE it, to show that it is. (Measure, Find, Replace.)

Shotgunning connectors isn't an 'upgrade', and may actually cause MORE issues, if they aren't a problem to begin with.

Keep things original unless you can MEASURE that they're a problem.
the Williams ones form that green goo in them. I've encountered a number of games running 3.7V to the chips courtesy of this "different metals" phenomenon. I would encourage replacing the high current power plugs for sure.

Does the RAM test just go sequentially from 11 to 38? I know 113 doesn't necessarily mean RAM 13 is bad but I moved it to 23 and the error moved to 23. Moved it to 38 and the error is at 38. Any other thoughts before I order some RAM? Anything else I should rule out first?
the order is bank 3, rams 31-38, then bank 1, rams 11-18, then bank 2, rams 21 to 28. it doesn't make sense, sure, but that's how it works. 31 is the first ram tested, that's why the catastrophic ram failures always come out 1-3-1. the self test stops on the first failure, so clearing that may result in additional errors detected after.

the write enables (4L/4M 7410s) and Special Chips have a breakdown of rams 1-4 and 5-8 (defined as lower and upper) in each bank, to further complicate things. lol
 
the Williams ones form that green goo in them. I've encountered a number of games running 3.7V to the chips courtesy of this "different metals" phenomenon. I would encourage replacing the high current power plugs for sure.


the order is bank 3, rams 31-38, then bank 1, rams 11-18, then bank 2, rams 21 to 28. it doesn't make sense, sure, but that's how it works. 31 is the first ram tested, that's why the catastrophic ram failures always come out 1-3-1. the self test stops on the first failure, so clearing that may result in additional errors detected after.

the write enables (4L/4M 7410s) and Special Chips have a breakdown of rams 1-4 and 5-8 (defined as lower and upper) in each bank, to further complicate things. lol
So if i move the suspect RAM to 28 and get an error of 128, there is likely only one bad RAM?
 
move it to ram 27. if the error changes to 1-2-7 then it's a bad ram. if it stays at 1-2-8 then that's different and can be figured out later.

you could have some other damaged parts.
127
 
Got the RAM today. Bought 2 of these on eBay.

1000045502.jpg

The first one booted without errors but failed the Auto Cycle a few times. The second one is passing so far. How long would you run it before being confident enought to button things back up?

Any other recommended preventative maintenance? The power board is pretty much new, cleaned all the RAM pins during debug, crimped terminals on all the power connectors, but left all the signal connectors alone.
 
I've purchsed quite a bit from APAR and Arcadeshop since I started and will continue to do so. In this case, I was searching around and found a guy on eBay from a town not too far where I grew up so I thought I'd give it a shot. (Unicorn Electronics, Aliquippa PA) Maybe I got burned, maybe not. I contacted him about a refund and will see where it goes from there. Im curious to hear where he picked up the parts from.

Second RAM still passing burn-in for several hours. So far so good...
 
I've purchsed quite a bit from APAR and Arcadeshop since I started and will continue to do so. In this case, I was searching around and found a guy on eBay from a town not too far where I grew up so I thought I'd give it a shot. (Unicorn Electronics, Aliquippa PA) Maybe I got burned, maybe not. I contacted him about a refund and will see where it goes from there. Im curious to hear where he picked up the parts from.

Second RAM still passing burn-in for several hours. So far so good...
what ram is showing bad? or is it random? I can't suggest what to do next unless I have numbers.
 
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