Intel Mini Abruptly Reboots

[After G]

Sorry to resurrect an old thread ...

I know it might be too late for the people on here who have had their problems, but I wanted to tell people about my experience with this problem, as it may save somebody a LOT of headaches in the future.

I had the "abrupt" rebooting problem as well. I thought it was bad memory as well, after reading what people did. I tried doing the "yes > /dev/null" thing, and running memtest. The problem seemed to be replicatable by running memtest, and the computer would randomly reboot.

After reseating cables again and again, resetting the SMC and PRAM, swapping sticks, etc., I happened to notice a picture on a Mac mini take-apart guide. (I was using the guide to help me take apart the Mini. It seems there is a hardware button to "reset PRAM" (according to the site, it resets BIOS). It is circled in violet in the picture. Push this button ONCE, and all your problems should be solved. I know about the keyboard shortcut, and tried it multiple times before opening up the mini (it's a pain to use the putty knife).



If anyone wants to read the guide, it's at http://hdtv.o0o.it/mini/

 

[Makosuke]

I'm re-dredging up a really old thread because after being away for a while I noticed the dredging-up post, and realized I never reported on my final solution.

So, for point of reference if anybody sees something similar:

In my case, the problem was indeed this specific pair of DMS RAM sticks. After seemingly endless iterations of testing, either stick would, WHEN NOT ALONE, eventually cause a spontaneous reboot.

I contacted DMS, they did an advanced replacement with a new pair of sticks, and those worked absolutely flawlessly from the get-go. A VERY weird problem, and not one most people are likely to ever encounter, but at least in my case it was indeed defective RAM.

Kudos to DMS, however, for agreeing to replace it and even advance-shipping me replacement RAM with a prepaid label to return the defective stuff.

 

[rsucre]

So new RAM does not overheat mac?

So with the new RAM, the Mac is not overheating? Or it does overheat (reaches 80C) without rebooting?

 

[Makosuke]

I assume the previous poster meant 80C, not 80F (which is basically room temperature), but yet another delayed, for reference reply:

The mini did NOT overheat with the replacement RAM--it maintained a totally reasonable temperature--and worked fine.

...but it wasn't registering temperatures any higher with the bad RAM, nor did it feel subjectively any hotter--the RAM sticks didn't feel unusually warm. I'm assuming that the problem wasn't that they were generating too much heat, but that they flaked out once they hit a certain ordinarily acceptable temperature.

I can say for sure the underside of my MBP, which uses essentially the same RAM, gets considerably hotter than anything in the Mini did.

Point being, the issue was NOT overheating or any kind of unusually high temps in the Mini, it was RAM that couldn't handle perfectly normal temperatures.

 

[rsucre]

Bad memory indeed!

Thanks to Makosuke, my abrupt reboot issue is now solved. I took the mini to the place where I bought (and installed) the RAM, they replaced one of the modules and the problem is gone! It used to reboot in every memtest. I was able to run > 5 full tests without a reboot.

 

[xpetex]

Thanks to Makosuke, my abrupt reboot issue is now solved. I took the mini to the place where I bought (and installed) the RAM, they replaced one of the modules and the problem is gone! It used to reboot in every memtest. I was able to run > 5 full tests without a reboot.

I had 2 gigs in my mini, and had these problems too. The store was completely unhelpful, so i ended up getting two 512 mb circuits from cruical, and so far it hasn't rebooted after 5 days or so. used to happen every day, and i could repeat it using memtest.

The reset pram thing seems interesting, perhaps i will try it to see if it makes any difference. it works pretty well with just 1 gb, but it'd be nice to have the 2 gb working.

thanks guys for making this thread. atleast i have a stable computer now.

sucks i had to use money from my own pocket to solve something that should be covered by guarantee, but i didn't want to be without the computer another 3-4 weeks like the 2 previous times when i took it in.

 

[xpetex]

The reset pram thing seems interesting, perhaps i will try it to see if it makes any difference. it works pretty well with just 1 gb, but it'd be nice to have the 2 gb working.

thansk for the tip, but it didnt' seem to do the trick for me, so it was back to 1 gb. well, that's fine.

 

[Cougar428]

Interesting problem. I know this is an old thread, but it's the exact same problem I'm having with my Mac Mini 1.66 Core Duo. If I put 2gb in it, it randomly restarts, with either of the 1gb sticks by themselves, it's fine. It's also fine with both sticks in, but the top one not plugged in correctly (so it's not detected). I ran it with just a single 1gb stick for about a year, not a single issue. I upgraded the hard drive the other day, and thought I might try plugging the second stick back in, and the problem may have returned. (Only had it reboot once so far, but that's once too many times).

Memtest works fine, passed 10 tests without issue, but I know it'll reboot itself at some point. A really annoying problem. I'll try with a 1gb stick and a 256mb stick and see how that goes.