This is a computer I built myself. It was really dusty. I opened it up, and vaccuumed it out (which apparently you should never do). At one point I took out the CPU fan, exposing the old thermal grease, and vaccuumed the fan. I pushed physically very hard trying to put it back on, bending the plastic landing nubs of the cooler, because I didn't know how to do it. Got it on eventually the correct way. Now it won't startup.

This motherboard [MSI P67A-GD65 (B3)] has 6 phase LED lights. Only Phase 1 lights up briefly, the fans spin, for about 2 seconds, then the computer shuts itself off for 5 seconds, then it starts up again and repeats.

The possible causes I know of is this:

  • Bad mobo LGA slot. Bent LGA pins (no CPU pins). They look fine on detailed inspection.
  • Bad connections. A short caused by dust or bent metal. No bent metal to my knowledge, it's a lot less dusty than it was, but dust could be in the connections now.
  • Static discharge. I was wearing wool socks on carpet while vaccuuming.. While I did ground myself to the plugged in/switched off case many times before and during, I may not have grounded myself enough
  • Bad RAM. The RAM worked before I vacuumed, and I tried swapping them out and having just one in the DIMM slot
  • Bad CPU. Some of the physical force may have transferred to the CPU, because the LGA connectors now have dot depressions on them. (See picture) Not sure if that's from me or from the chassis clasp that is built into the mobo, which also puts a lot of pressure on it.
  • Bad PSU. Irregular voltage coming from PSU. Seems unlikely since it worked earlier that day.

The first time it did this reboot loop, I noticed that I hadn't seated the CPU cooler firmly enough. Once I reseated it, same problem. Then I used 99% isopropyl alcohol and removed the old thermal grease, and replied new one on. Still no luck.

Are these dot depressions normal or physical damage? Multiple people have told me this is normal now. CPUs rarely break, so now I suspect I need a new PSU and/or motherboard.

LGA slot depressions

The slot

enter image description here

This is probably what happened to it: https://www.youtube.com/watch?v=AhlyMdiLc0E

  • Hard to tell from that picture, any damage to the socket on the motherboard? – Moab Jan 8 '16 at 20:04
  • Did you clean old thermal grease off and apply new? – Moab Jan 8 '16 at 20:05
  • No socket damage, AFAIK. Yes new grease. – Jonathan Jan 8 '16 at 20:25
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    The dots/dents on the CPU pads are from the LGA springs pushing against them, this is normal. Since you ran with out the heatsink attached properly, you may have already cooked the CPU (permanently). Also, vacuuming out a computer is a bad idea, as vacuuming creates static electricity (unless using a special vacuum for it), which can kill electronics. You need to test the hardware components individually in a known-working system. – Ƭᴇcʜιᴇ007 Jan 8 '16 at 20:35
  • I was indiscriminate with the vaccum in my dustlust, and I probably did create a static discharge without me knowing – Jonathan Jan 8 '16 at 21:18

You can try the reset of the CMOS. Also, to remove the motherboard battery.

If nothing works, it is possible that the Bios is corrupted. That's often due to this issue when we get a boot loop. For this purpose, you need a SPI programmer in order to be able to externally flash the Bios.

More information: Guide to flash a Bios with a SPI CH341A mini programmer

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    Welcome to Super User! Thank you for you contribution, but can you edit your answer to include the essential information on flashing a BIOS with a mini programmer here, and provide the link for reference. Thanks :) – bertieb Jul 3 '18 at 11:21

I purchased a replacement motherboard of the same make/model off ebay, and everything worked like a charm. So the vaccuuming must have fried the mobo due to static discharge.

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