[andreas_g4]

I have 3 GB memory in my aluminum iMac. One GB is the Apple Hynix module, and I got the additional 2 GB Kingston from a local dealer.

Just the other day, I powered on the machine, and it produced the faulty memory beeps. So I uninstalled the 2 GB, and it run. The day after, since it just stopped working all of a sudden, I reinstalled the module, and it worked again. A day later it won't, now it does again. It's not the memory bank.

I just have to exchange the faulty module under warranty, so it's not really a big deal. I am just wondering how this is possible? I mean, a memory module is pretty static (read: no moving, mechanical parts), and shouldn't it work or not work? If it's not in use, it's in an anti static box.

Wondering.

[ghporter]

As it warms up, any electronic circuit board can flex, and that can cause problems with not-perfect solder joints. This is not common but not atypical of all sorts of products. It's the most common "intermittent" device problem in the book-and the most difficult to prove. Fortunately, we're talking about a part that is almost trivial in cost, so a warranty swap out won't be a problem.

[andreas_g4]

I was ruling that out since it doesn't bother the system at all being in sleep mode all night long. Granted, there's some current in the modules, I would just think that sleep mode cooles off everything. And there are no issues whatsoever when the machine is running.

Heat sure is the most plausible explanation, but still.

[ghporter]

It doesn't have to be warm to cause distortion. It could be that being relatively warm made the board or component line up properly and being too cool caused the connection to be broken...