How to determine if it's a motherboard or CPU issue?

Question

Note that I read the main suggested question and my situation is different, so that's why I'm asking again.

I'll explain everything in detail (this will be a little long, but I'll make it as short as I can). I'm trying to figure out if my motherboard is still 100% fine and that it's just the CPU that's overheated, or if the CPU and motherboard have both failed.

Here we go:

My computer was working just fine until one day I got a little curious (I wasn't so wise at the time). What I did was I opened the computer because I wanted to see the CPU in detail. I removed the heatsink, the CPU's latch, and removed the CPU.

Everything was going fine until I had some trouble getting the CPU back into the socket. I forgot which way it was originally in, and wasn't sure if I had originally forced it in the wrong way when I put it back in. When I turned the power on nothing happened. I opened it up and kept flipping it 90 degrees until it eventually went back on fine. Many pins were bent in the process that I couldn't really straighten. I never put the case back on, and I accidentally touched the heatsink exposed while the computer was running in BIOS. The screen started flashing and then it just rebooted. Everything still appeared to be working perfectly, so I figured there were no problems at all. Basically, it still worked even after bending many pins.

I got curious again, but this time I suffered the consequences. I opened everything up and took the CPU out again to clean things. I placed it back in the socket and accidentally hit the power on button before putting the heatsink on it. I then noticed that it still worked, even after sitting running with no heatsink for almost 15 minutes. I applied toothpaste, but noticed that soon after it wouldn't boot, and I had lost the BIOS battery(not sure if that would affect anything). POST checks fail, no beeping sounds are made (but that could be simply because the CPU is dead, not the motherboard), but that heatsink still spins so power is still working on the motherboard somewhat, so I was led to believe there's still hope for the computer.

I have yet to try a new CPU because I'm worried about these few things:

1.What if the motherboard is doomed, and the CPU I buy dies as well, leaving me with nothing but lost money and no computer?

2.What if there's nothing wrong with the motherboard and it's all the CPU, and I buy a new CPU and it dies on me again, leaving me even less options?

Given that power still runs to the heatsink but the pins are still bent so the CPU is most likely dead (but what if it's the motherboard not functioning because of the pins and the CPU is really fine?), should I buy a new CPU and risk it (cheapest method possible, as I can get a compatible one for $3.00 U.S.D.)? Should I try and see if the motherboard has power working using a multi-meter or something to determine voltage/current/etc.? Should I do them all?

Solution 1

Between using toothpaste, running without a heatsink for that long. and the bent pins I would say you definately need a new CPU. I would recommend buying the cheapest one of these or similiar

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR11.TRC1.A0.H0.Xthermal+past&_nkw=thermal+paste&_sacat=0

and just replace the CPU. Good chance the motherboards fine. Just remember the CPU has an arrow on one corner that will help you know which way it goes.

On a side note sometimes messing around can get expensive so be careful, look-up some knowledge on the subject first, and enjoy.

Solution 2

TL;DR: You messed up at the very least with the CPU.

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You made a couple of mistakes here. Some bad, some not necessarily so bad.

One, you forced the CPU into the socket. This damaged the CPU (bent the pins), but is unlikely to have damaged the motherboard, because there is nothing (in CPU sockets that I know of, at least) that protrudes from the motherboard into the CPU. Verdict: New CPU likely needed, motherboard probably fine.

Two, you tried to "fix" the CPU by bending the pins back. The CPU is incredibly sensitive to electrostatic discharge, and unless you took precautions while handling it, it's quite likely that simply by touching the pins you applied voltages where they weren't supposed to be. Have you ever touched the handle of a shopping cart and felt a jolt from that? It's the same thing. Also, the pins themselves are delicate; it's far from unlikely that you by trying to bend them back into position caused internal damage to the CPU. Verdict: Jury is still out on this one, but there is a distinct possibility that you damaged the CPU.

Three, you touched the CPU (by proxy of the heat sink) while it was powered on and running. This comes back to ESD, same as above. The heatsink isn't supposed to matter, but it's possible that by offering an alternate ground path or voltage on ground, you invoked less magic. In addition, there is always the possibility that you inadvertantly short-circuited something, which certainly would lead to odd behavior and possibly damage. Verdict: Not necessarily catastrophic, and fairly likely only enough of a disturbance to screw up internal state, but depending on conditions we cannot really rule out physical damage to components within the computer, including the CPU and motherboard.

Four, you ran the CPU for a fairly long time without adequate cooling. While the CPU should have shut down automatically when it got too far above its rated safe temperature range, 15 minutes is a pretty long time for a modern CPU to run without anything more than passive, convective cooling. Verdict: With a properly functioning CPU, should not have caused any permanent damage to either the CPU or motherboard. With a potentially damaged CPU, might have caused further damage to the CPU.

Five, you put toothpaste on the CPU. Toothpaste is nothing like thermal paste. If this was limited to only the top side of the CPU integrated circuit and nowhere else, by itself this shouldn't be critical, but any contaminants left on the motherboard may cause problems now or in the future. (Also, thermal paste does absolutely no good by itself; its purpose is simply to reduce the air pockets between the CPU and the heat sink base.) Verdict: Unlikely to be a permanent problem in itself if and only if it was applied like thermal paste should have been (not touching anything conductive); otherwise, may well be a problem unless you remove it completely.

So, in summary, you will at least need to get a new CPU, because after these ordeals the one you have is likely to be damaged beyond repair, and even if it can be coaxed into working you cannot know what internal damage there is which could conceivably result in everything from iffy operation to possibly even presenting a fire hazard. You need to clean everything off properly, and install the new CPU and your heat sink properly. We cannot say for certain that your motherboard is OK, but I wouldn't assume that it's damaged in a permanent way. The rest of your computer is probably fine, including RAM and storage (HDD/SSD).

Frankly, I'd recommend that you get a professional to do the hardware cleaning and installation for you. Definitely don't start poking around with a multimeter inside the computer; it is unlikely there are readily available measurement points that you can just measure voltage at and tell whether they are "good" or "bad", and there is quite the risk that you'd mess up further.

Comments

[cybernard]

What is the make and model of your motherboard? You can not substitute toothpaste for thermal paste, get some artic silver or similar. Unless you have a super cheap motherboard it is probably fine.

[cybernard]

Do you see any leds on the motherboard? They may be diagnostic and if your read the motherboard manual you may find one that signifies everything is fine.

[Doktoro Reichard]

A painfully long wall of text to read (that I personally would just cut down to "CPU pins bent, then ran without a heatsink for 15 minutes"). Without proper cooling, CPU's can reach 250 degrees, although it should have shut down to prevent damage. cybernard's advice is in order: toothpaste isn't a suitable replacement for thermal paste and without knowing motherboard or CPU model we can't say much other than most likely the CPU has burned.

[Andrew Morton]

Please don't go poking around with a multimeter: you are likely to make a short-circuit with the probes and cause some real damage, possibly to your life. Jayson's answer looks good to me.