Random Restarts

Hey guys,
So as mentioned before I have had the same issues. I replaced my factory mini RAM (2x526) with factory 1GB RAM from the Intel Mac Book Pro. I figured that this was also apple RAM (Samsung) and should be good. No dice. restart after restart. I then replaced that RAM with some 1RG RAM chips I purchased at datamem.com and I have not had any restarts in the last several days. To me, all issues point to the RAM. I have been running Ripping with Handbrake, converting with iTunes and watching EyeTV all at the same time trying to stress it out, and it performed flawlessly, which made me very happy. I feel that Leopard is very touchy with RAM. I think the only real solution to this issue is to keep replacing the RAM with two different chips until you find a working pair. It is a pain, but if you buy RAM, and feel that it is suspect, you can return it for a refund and try again. To me it is worth the process to have an amazing media center.

Just something to add to the discussion. I don't believe it's just the RAM, and here's why.

We have a brand new 1.83GHz C2D Mac Mini with OS X 10.5.2 and 1GB factory RAM installed on it. It's restarted itself a half dozen times in the last two weeks. Today, it just shut down - no restart.
We also have a 17 month old 2GHz C2D iMac with OS X 10.5.2 and 2GB Apple-installed RAM installed on it. Since I upgraded to OS 10.5, this one has restarted itself twice. Unfortunately, it's too old for Warranty service.

The only things these two machines have in common are OS X 10.5.2, mostly the same software running and the network we share. I believe the OS has something to do with it because it didn't start happening on the iMac until 10.5 was installed.

Other than that, we have a 1.83GHz iMac running OS X 10.4.11 and a 2.4GHz MacBook Pro running 10.5.2 and neither of them have experienced random restarts.

The only other concern I have is that I don't believe the iMac did a full restart - I think the screen just went blue and then the Finder reappeared and everything that starts up automatically on boot did so. I'll try to watch that more closely on both machines.

As said in response to your other post on this: I think we have to be careful not to risk mixing potential symptoms of one issue with another and possibly drawing erroneous conclusions as a result.

It's unlikely, for example, that MacOS 10.5.2 is in itself complicit in this issue, since if it were, then a wide range of systems would inevitably suffer the same problem - indeed, possibly even every Mac running MacOS 10.5.2. What is more likely (and indeed not uncommon) is that a MacOS update has brought to light an issue with the installed RAM which renders the system unstable. We've seen this almost inevitably as a result of MacOS updates each time they are released, and particularly when 3rd party RAM has been added. In many ways it's this factor which has built up the folklore of Mac systems being very temperamental with memory.

The only thing that seems consistent is memory in these random restart cases. Given the lack of opportunity to troubleshoot to any depth, this may itself be a misleading conclusion to draw, but it does appear broadly complicit in reports of the behavior so far.

I have the random restart issue.
I have a 2.0 Mac Mini I Rented in November of last year with upgraded ram and HDD. I am using a LG 32LX2D-AA 80cm LCD. I purchased it with 10.4 and recieved the 10.5 drop in pack a couple of weeks later. I noticed no probs with 10.4 but I can't say for sure if I just missed it. Installed the drop in and only discovered the problem after noticing half my iTunes library had actually copied across from my old drive, this was due to a random restart that occurred while i was copying it. I successfully managed to witness it occurring with all external devices disconnected (except the LCD TV).
I have no scheduled shutdowns, it is not regular, it is random and not always a restart...
I contacted the store where I purchased and they suggested re-installing 10.5 to rule out if it was leopard or not so I did. At first it was ok but then instead of restarting it would go to "sleep" but was unable to be woken without holding the power button down. Eventually It began with the random restarts again. Sometimes it would restart a couple of times... the chime would sound, black screen, chime again, then when restart was almost complete, frozen screen, it would have a small glitch of about 9, inch long vertical black lines staggered in lines of three or there would be pixellated colour glitch of green and pink across the whole screen. This was when it was really bad and I couldn't get it working, even with a rest to cool down.
I have taken it in to the service department of the reseller three times now and every time over a week on the bench stressing the cpu and no fault. It's now been there for 30 days, 1.5wks on the bench no fault and apple have given me a case no# and a contact. All the time I am paying monthly rental for what was supposed to be a cool media centre.

I really believe that the mac mini is not compatible with LCD TV's and don't know what to do if that is the problem and a new replacement unit ends up the same, I have a 36 month contract of hire and can't afford now to get an apple display (which will be no where near as cool as my LCDTV)
I found these topics which I informed the service department of in email http://discussions.apple.com/message.jspa?messageID=6914286#6914286 http://discussions.apple.com/thread.jspa?messageID=6914199#6914199 aswell as this one we are in and more which aren't necessarily so similiar.

Mac Mini 2.0gHz 2coreDuo Mac OS X (10.4.11) 2gb Ram (Factory ram installed on purchase by the reseller SwissBit i think)

I see no one else has gotten any further.
I returned the unit to the store with the LCD Tv, it was there for three weeks no fault! I don't believe it.
I got it home and now I have an IBM CRT G74 monitor and a UPS with battery backup. still managed to get it to randomly reboot. I even managed to get it to do it after a safeboot. I simply ran 6 movies in quicktime at once and after 35 mins under safeboot it restarted.
I found another thread on mac rumours interesting read: http://forums.macrumors.com/archive/index.php/t-214138.html
Apple want me to take it to another service provider however these guys want to charge me $77 if they can't fault it.
Has anyone had any luck with their service departments? Anyone solved this problem? Please get back and report.

I have taken the unit to the service provider. They had it fault within ten minutes and they think they've narrowed it down to the logic board. They have informed me that they are going to replace it and do some further testing.

Please watch to see if the screen asks you any questions, I have a simular problem, my Macbook restarts all the time, but it usually asks me if I want to shut down, basically, I do nothing that would cause that window to come up. I sent mine back to apple, and they suppositly fixed it. It ran about 5 or so months error free, now it is doing it again. When I sent it back, they replaced a few parts interally. I have been very fustrated with the whole thing, since it is no longer underwarrenty. I have other macs that run with no problems, older in fact, and have been a Mac owner since '87. I think mine is some sort of lemon, but I nor anyone else seems to know what might be the actual problem

The service provider informed me that the logic board was not the issue. One of the two RAM sticks is faulty and I have to take it back to the place of purchase to get it replaced under store warranty as the RAM is not apple RAM it's not covered under the apple care protection plan. The Place of purchase where I got the mini is happy to replace the faulty RAM and have also agreed to pay the second service provider's diagnostic fee.
As indicated in the other macforum thread that this issue is discussed it is the RAM that causes it... only one of the RAM sticks is faulty however and did not show as faulty when tested... it was only by process of elimination that they knew it was bad.

Thank you for posting the conclusion reached by your service provider - it does seem that memory is a primary culprit in these situations, though it's clearly not easy to diagnose since many testing utilities are not sufficiently thorough to find and report the issue. It's important though, for others with similar symptoms, to bear in mind that RAM is a very likely suspect, even if it seems easy to drawn other conclusions! It must also be said that many service providers would simply swap out the logic board sine that's a simple and quick 'solution' to many faults!