2 Replies Latest reply: Jun 28, 2010 8:21 PM by rjcchan
rjcchan Level 1 (25 points)
My iMac has been having frequent freeze-ups - i get the little black box that says i have to restart the computer.Tends to be memory intensive tasks - for example i can copy from one disk to another but can't clone.

I have been trying to use the hardware test from my original install disks. The only thing connected is the apple keyboard and apple mouse. Ram sticks are from crucial and i have had them in there since i bought the computer ( bought it when they discontinued the 17" model). Hardware test freezes:

1.first time while trying to do its initial probe
2. second time at the language selection window
3. third time 1min 30sec into the extended check
4 fourth time at 22sec into the regular check.

if i shutdown with power button, unplug and wait maybe 15 minutes, the computer will boot into the usual desktop but sooner or later i get another freezeup. I am concerned that the operating system will get borked from the frequent powering off with the power button.

do these symptoms suggest any particular problem? could a failing battery cause this?

17" iMac intel, Mac OS X (10.6.3)
  • Scott Billings Level 4 (1,655 points)
    Simple way to test whether or not this is a memory issue is to remove one stick of RAM and run AHT again. Does it lock up? If yes, swap the sticks of RAM. If it still locks up, your RAM is likely fine.

    You can also inspect the RAM sticks for any signs of physical damage. It's rare, but it does happen, that you'll see some kind of residue that looks like it came out of one of the chips. It's usually white in color, but it doesn't have to be. Electricians and what not tend to call that "letting the smoke out" of a chip. If you see anything like that, you know that bit of RAM is dead.

    Kernel panics can happen from bad RAM, but more often it's the result of something even worse. So, hope that all it is is some bad RAM. If you're a religious person, praying might be a good idea. The other alternative is the logic board is going bad, and if that's the case, you'll just want to buy a new computer.
  • rjcchan Level 1 (25 points)
    turns out it was one of the ram modules. i also downloaded Rember and tested one at a time just to confirm it.