computer question - ram fried

[gigpiglet]

one for the computer guys..

any reason you can think of that would fry ALL EIGHT ram DIMMS in a mac pro?
machine is in a rack, has been there for some months.
nothing changed.
computer worked one day.
failed POST the next day.
no lightning strikes etc..

some trial and error deduced that every ram module was dead.

machine back up and running now (with some spare ram i had)
but obviously not wanting to repeat the issue...

any reason you can think of?

[Drumstruck]

Most h/w faults occur during power up or power down - RAM is a sensitive little soul and most RAM banks are in pairs - only one faulty DIMM per pair could cause the pair to fail.... guessing some microspike may have occurred during power down....

[mike]

Here's my 2 cents because you asked, it might only be worth that The power supply unit can often be the culprit. You might want to have it checked out and tested before connecting it up again. I had a PSU take out a few hard drives over a period of a month before I pinned down what the problem was. Also, how clean is the power going in to your rack? Do you use a power conditioner?

Also, how did you determine each RAM module was dead? Do you have a 2nd working machine to test them in? You may have some dead ports on the motherboard as well.

[gigpiglet]

hi mike.
power is pretty clean... totally separate circuit for the studio (all the "building" stuff is on a different DB/ RCD/ etc)
and the computer rack is on its own power conditioner in that rack
this set up has been operational for some time

tested the fact that all 8 DIMMS are fried in known good machines (i have 5 mac pro towers here)
and also that known good RAM, works in all 8 slots in the machine (i.e., its not the slots dead, it was the ram in them)

i agree (and with some googling) feel that it could be PSU issue... im running the machine with bare minimum ram for now, to see if i have the issue again (no point frying 24GB of ram to find out its a PSU - losing another 8 will be enough)

[jay_f]

Sorry to hear Gareth,

You could always give Apple Hardware test a go to try and work out if the dead ram was the disease itself or just a symptom of some other issue. It's either on a disk that came with your mac, on the recovery partition, or available online depending on which model mac pro. The machine "Should" fail if something is still not OK.

All the best

James