I have seen this happen this happen to several machines lately. Look for these sympthoms as they are an indication of a failing RAM chip, or a bad DIMM socket on the mobo.
- The system freezes up at random times during bootup:
- during POST
- at the Windows logo
- just before login screen
- right after login
- System turns on, and stays on but never even reaches post
Note that read/write memory errors are not on the list here. Those are dead giveaways, and curiously they were not occurring in most of the cases I worked with. If you experience intermittent, but consistent sympthoms like the ones listed above, start pulling out DIMM’s out of your system. Chances are that one of them might be going bad, or that the DIMM socket itself is on the fry.
Once you identify the “bad” DIMM, take all the memory of the system and put a chip that you know to be good into the slot where the bad one was before, set the strictest POST in your BIOS and try to boot it few times. You don’t have to go all the way into windows. You just want to see if it passes through the memory test at the POST. If the sympthoms go away, you are in the clear – it was just a bad DIMM. Get a new one and go on with your life. If they continue, or if you can’t even boot, then you may need to get a new mobo.
[tags]dimm, ram, memory, bad memory, bad dimm, dimm socket, freezing at post, freezing at windows logo, freezing at login, blank screen on boot up[/tags]
Don’t forget to destroy the bad memory after you confirm it’s death. Too many people will see it in the trash and take it back out, especially fellow admins. I can’t tell you the number of times I have had to troubleshoot the same issue only because some admin tried to help save money by picking through the trash. Same goes with bad network patch cables . . . cut the ends off for added insurance that it will never reappear in your stockpile.
Oddly enough I’ve never had memory go out on any of my machines (crossing fingers now haha). hard drives yes memory no. But i would have expected memory read write errors so thanks for the info gives me a clue to know what to look out for.
Criag – actually, I almost never throw out bad RAM. I put it in a box labeled BAD RAM. I always figure I will use it for something cool. Haven’t figured what I’d do with them.
I also have around 20 bad laptop hard drives stacked up on the shelf behind me. Partly because I don’t feel like figuring out the proper way of disposing them with regards to confidentiality policies and etc. Every once in a while I take one of them apart to get the cool magnets and the shiny platter out of it. I have several of them hinging off my lamp at work. :)
Starhawk – You may or may not get memory read errorsIf the DIMM socket on the motherboard is going bad, you will likely see behavior like the above.
Another time to suspect bad memory is when the computer is suffering random syptoms with no rhyme or reason. I’ve had computers that didn’t have a pattern to their failure – might not make it past POST one time, the next it might work fine, the next Windows might freeze, the next one application exits with an unusual error, etc – which came good by replacing the RAM.
Also try a memory tester – since I found out about memory test bootable CDs, I haven’t had a stick of bad memory that wasn’t detected by the CD. Saves having to pull a ‘puter out of it’s nest of cables and whatnot.
So, can you recommend any good memory testing tools? I think I have one or two in my toolbox, but I’d love to hear what you use.
I have one on a bootcd somewhere that a sysadmin mate made, it’s a linux memtest and does a decent job. Couldn’t find that disk here at work, so I downloaded the Microsoft Online Crash Analysis memtest tool which seems to do the trick… and I just never bothered finding the other disk :)
I don’t know whether the MS one is an excellent tool or just an average one, but it seems to have worked fine for me so far.