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I have been using a Poweredge 2850 for a while now and it's been fine. It was removed from the rack for about 24 hours (carefully, no knocks or bumps and was stored flat as it would have been in the rack, albeit on the floor).

While it was on the floor I was asked what CPUs were in the machine so rather than plug it in and turn it on I just lifted the heatsync off one of the CPUs to have a look. The CPU was stuck with thermal paste to the heatsync so I gave up and put it back.

About 10 minutes later I was asked again so I just plugged it back in (Both PSUs and ethernet, nothing else) and went to turn it on.

  • I get no error messages just an orange "Poweredge 2850" message on the screen.
  • The hard disks flash once and then the lights go off.
  • The fans all spin up but barely at all, nowhere near what it would be like if it was actually on. Barely audible.
  • No visual output to the monitor on either the port at the front or back.

I've since reseated the CPU twice more in case that was it, found a thread on the internet which suggested reseating the RAM, CPU, and HDDs, all of which I've done to no avail.

If any other information will help with a diagnosis then please do ask!

If anyone has any suggestions they'd be received with much appreciation!

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Your explanation doesn't make much sense. If the CPU was stuck to the heat sink, what did you put back? Did you put the CPU back in the socket while the heat sink was attached to it? –  David Schwartz May 31 '12 at 11:28
    
That's correct, but I've since separated them and placed them back individually. –  Ben Swinburne May 31 '12 at 11:33
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Uh, you shouldn't be able to put the CPU back in the socket while it's still attached to the heatsink. I'm not familiar with 2850s, but there should be some kind of latch or lever on the socket that has to be opened to remove the CPU and closed to lock it into place when you remove it. Can you upload pics of the CPU and socket. I get the feeling that you probably forced it back into the socket while in a locked state and damaged the socket. –  MDMarra May 31 '12 at 11:39
    
@MDMarra: Correct. It's a ZIF. Force used to remove or insert the CPU can damage the contacts inside the socket Usually, they can withstand a forceful removal (but not always). A forceful insertion, however, is almost always catastrophic. –  David Schwartz May 31 '12 at 11:42
    
There was indeed a discreet lever to lock the CPU in place. Having lifted the lever, dropped in the CPU and dropped the lever it booted first time! Moronic of me, but fortunately not catastrophic! Thanks for all your help. –  Ben Swinburne May 31 '12 at 13:18
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3 Answers 3

up vote 4 down vote accepted

If the only thing that changed was you removing the CPU from the socket, then it's a safe bet than you didn't return the CPU or heatsink back to the socket correctly. If the heatsink isn't making good, tight contact, then you'll see this behavior. Make sure it's screwed down or clipped down evenly.

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Between you posting your answer and me posting my question I found this link which suggested similar. I have taken the CPU off of the heatsync, positioned it correctly in the seat and then mounted the heatsync on top - and having read this, triple checked it's secure. I am about to try the NV RAM jumper also suggested in that thread. –  Ben Swinburne May 31 '12 at 11:24
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You should also check that you did not bend any pins and damage any contacts when removing the CPU. –  MDMarra May 31 '12 at 11:26
    
I don't suppose you know if the case lid has to be on do you? Taking it on and off every time is irritating but since I don't know if that will affect my testing I have been taking it off and putting it on every time I try anything! –  Ben Swinburne May 31 '12 at 11:27
    
There are no bent pins and no visible damage to any of the contacts either :( –  Ben Swinburne May 31 '12 at 11:27
    
Having cleared the NVRAM I'm now getting an error message - E0780 - which according to this page is indeed missing processor 1. I've checked it's secure, and it's not damaged. Is there anything else I can try? –  Ben Swinburne May 31 '12 at 11:36
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I suspect the damage is done. You can't see it, it's inside the ZIF socket. Most likely, the arm wasn't all the way up when you inserted the CPU and the insertion force deformed the contacts inside the socket.

If it took any force to get the CPU in the socket, this is almost definitely the problem. It should "drop" in with zero force, that's why it's called a Zero Insertion Force socket.

Theoretically, it might be possible to remove the plastic cover (the part that moves with the arm) and unbend the contacts. But it's a heck of a long shot.

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It didn't take any force to reinsert the CPU as far as I could tell. It did seem to just drop in, granted I had the heatsync on top so something my have gone awry but as far as I'm aware it went back in fine. How easy is it to take the plastic cover off? Are they even designed to come off? –  Ben Swinburne May 31 '12 at 11:49
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I am willing to bet nothing is damaged, you just didn't reseat the CPU completely. It seems as though the only way to get the CPU back in the ZIF socket is to remove the heat sink. The heat sink in mine has a tab that prevents the ZIF arm from moving while the heat sink is down on the CPU. You can't re-seat the CPU with the ZIF arm closed. You can't move the ZIF arm far enough out of the way of the heatsink to seat the CPU. Even if you could get the ZIF arm out of the way, you wouldn't be able to close it after the heat sink is in place. (The ZIF arm is a small squarish all-metal arm that is on one side of the ZIF socket toward the front of the case, down against the circuit board. It is not the two wire-like arms that held the heatsink down.)

To fix this, remove the CPU and heatsink. Separate the two (don't pry), and clean the CPU. Then lift the ZIF arm and put the CPU back in. Close the ZIF arm. Then get some thermal paste, and apply it to the top of the CPU per the directions. Then put the heatsink down on top of the CPU, and lock it in place with the two heat sink arms.

Sorry this is so much trouble, but someone decided to save a few bucks by using a heatsink that doesn't play well with the ZIF socket.

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