Identify Bad RAM Chip(s)

[Johnnya101]

Before putting away my IIfx a couple years ago, I remember one day it gave the chimes of death. I eventually ruled it out to be one of the eight ram modules being bad. I am awaiting an SCSI2SD for further testing. Is there any way to test for a bad module outside of the computer? I still don't know which one of the banks of four is bad, because I don't think I can have 7/8 modules installed. How do I know from there what chip is bad? These are 16MB sticks, so pretty pricey and I think worth the effort of saving/repairing.

 

[LaPorta]

For certain you need al of a bank populated to work, so bank A needs to be full and bank B empty unless you get a nee stick.

 

[trag]

For certain you need al of a bank populated to work, so bank A needs to be full and bank B empty unless you get a nee stick.

To expand on what LaPorta wrote, while you can't test with 7 out of 8 SIMMs installed, you can test with 4 SIMMs installed.

So start by removing the RAM in Bank B and test. If it works, then the bad stick is one of the oens you removed. If it fails, then it's one of the sticks still in the machine.

In the first case, now you know that the four sticks in the machine are good. You can test the removed sticks, which have a bad one hiding amongst them, by just substituting them one at a time for one of the good sticks.

In the second case, the four sticks you removed from the machine are probably good, so swap sets of four, make sure that they're good. Then do as in the first case.

The only issue with this methodology is I have on rare occasions seen failures that only became apparent when eight sticks were being used. Probably doesn't apply to your situation though. And you'll know quickly enough.

 

[LaPorta]

Thanks...that garbled nonsense I wrote is what you get when you post on the run!

 

[trag]

Thanks...that garbled nonsense I wrote is what you get when you post on the run!

It was good stuff. I couldn't remember that Bank A needs to be populated.

But we just don't know what level of detail folks asking for help need, so when there's time, I try to provide excessive detail.

 

[Johnnya101]

Thanks for the help. I just got my SCSI2SD here today, so I plan on getting the IIfx running first with another good set, and I will swap modules from there.