Question Tried replacing my CPU cooler, now PC turns off after half a second.

[Vithonill]

I tried installing the Peerless Silent Assassin on my PC bc I got thermal throttling with my built in AIO cooler.

It was a Lenovo T7 prebuilt, MoBo is a Lenovo 3715, LGA 1200 chipset. Should be compatible.

But I must have fucked something up because now that I installed the thing it no longer turns on for longer than 1 sec.

I have removed the CPU and it will run just fine without the CPU installed but I am not a tech guy so idk what that means/if it means anything.

I put on way too much thermal paste and apparently I got some in between the CPU and the socket (I think)

I don't think any pins are bent but I can't see them very well. They look straight when looking at them. I have cleaned the socket and the CPU plates with 99.9% alcohol and a very soft clean paintbrush.

As soon as I put the CPU back into the socket - cooler or not - the PC will turn on for one second and then off again. Idk why.

I have tried everything I can think of:

Remounted the Cooler and plugged in only one fan into CPU fan.

Remounted the Cooler and plugged in fans into CPU pump.

Remounted the Cooler and plugged the AIO pump back in (it has a 3 pin connector so I figured maybe that is it)

Remounted the Cooler and plugged the pump in and every other fan.

Remounted the Cooler and plugged in the RGB of the pump and every other fan.

Remounted the Cooler and plugged in fans into the CPU fan and CPU pump only.

Remounted the cooler and plugged out everything - fans, RGBs, GPU.

Dismounted the cooler and did all of the above.

Reset the CMOS battery.

Replaced the CMOS battery.

Left the CMOS battery out for 5 mins.

Put the cooler on tighter.

Put the cooler on lighter.

Reseated RAM twice.

Tried booting with only one stick of RAM.

Tried booting with the CPU removed but the latch closed (it ran fine)


Idk what else to do at this point or what to replace. Did I fuck my CPU by screwing on the cooler too tight at some point? I read that is pretty hard to do.

Did I fuck up my socket? The CPU fit in very nice when I reseated it (I did that twice) and the pins look good to me.

My local tech shop is currently not sure if he even wants to take my case (lol). So I am on my own. Money is a bit tight so I dont wanna pay $120+ for a new MoBo if I dont have to. Nothing on my MoBo lights up to indicate any faults...

What I find odd is the fact that this only happens when the CPU is in the socket. When no CPU is in the socket it will run for more than the one second.

 

[Vithonill]

Here are some pictures:

https://imgur.com/a/mr2b1b7

View: https://imgur.com/a/mr2b1b7

 

[80251]

Your situation is the kind I dread the most.

Running modern CPUs without some sort of heatsink or cold plate will result in the CPU instantly overheating and shutting down.

You could ask someone w/the same type of motherboard if they would be willing to test your CPU in their motherboard, or, alternatively, test their CPU in your motherboard.

It used to be the PSU was the most failure prone component in most PCs, you could try using another known good PSU. Or at least test the PSU outside of the system (by jumping some of the pins on the 24-pin connector) then testing the +5V, +12V, +3.3V outputs on the PSU.

The socket pins looked OK to me, you really need a powerful magnifying glass and lots of light to be sure though.

The PSU will shut down if it doesn't get a POWER-GOOD signal from the motherboard.

 

[Vithonill]

I think I found the culprit:

https://imgur.com/a/PYZroeR

View: https://imgur.com/a/PYZroeR


I made some scratches into the board while trying to get the backplate off (the metal of the backplate bent before the adhesive gave out, idk what kind of glue they used) and I think this is why the PC is not booting properly.

The CPU itself was cool to the touch and I think it never got any power from the board. Do you think these scratches are causing this issue? Is my CPU fine? I already ordered a replacement motherboard and I hope it's not the CPU thats the issue since it is so much more expensive than the board is..

 

[Lafong]

You say that this is a Lenovo pre-built and "I got thermal throttling with my built in AIO cooler."

Did this machine EVER run OK?

Was the thermal throttling on the AIO a new development and the machine had been running well previously?

Do you have ANY idea why your AIO cooler apparently quit cooling?

 

[Vithonill]

Tbh I never checked. It might have been broken from the start.

I got the performance I wanted in games so I never bothered checking. All I know is that about 3 months ago I first ran into thermal throttling issues so I replaced the thermal paste (everything went fine) and the PC ran totally fine bar the throttling for about 4ish years now. After I replaced the thermal paste I didnt check for throttling again because I forgot to.

So I must have fucked something up when trying to replace the cooler. Since the pins look fine and the CPU looks fine as well the only conclusion I can come to is that the scratches I made on the back killed the board.

I ordered an MSI Z490 as a replacement since it seems to fit well within the Lenovo case and I hope its just the board that is broken.

 

[Vithonill]

You say that this is a Lenovo pre-built and "I got thermal throttling with my built in AIO cooler."

Did this machine EVER run OK?

Was the thermal throttling on the AIO a new development and the machine had been running well previously?

Do you have ANY idea why your AIO cooler apparently quit cooling?

No idea why it the cooler quit working, but since I had already replaced the paste once and did so again about 3 days ago and it was still throttling I came to the conclusion that the pump must be broken.

Which fits in well within what you read online which is that they often break after 3-4 years. Not sure why this exact pump quit working or if it ever was working.

 

[Lafong]

No idea why it the cooler quit working, but since I had already replaced the paste once and did so again about 3 days ago and it was still throttling I came to the conclusion that the pump must be broken.

Which fits in well within what you read online which is that they often break after 3-4 years. Not sure why this exact pump quit working or if it ever was working.

Just re-reading what trouble-shooting you have done.

Most of your attempts appear to be trying to get the AIO working.

Forget the AIO for the moment.

How sure are you that you have ever properly mounted the Peerless Assassin air cooler?

 

[Vithonill]

Just re-reading what trouble-shooting you have done.

Most of your attempts appear to be trying to get the AIO working.

Forget the AIO for the moment.

How sure are you that you have ever properly mounted the Peerless Assassin air cooler?

I mean I followed the instructions best I could, but given your comment maybe 50/50?

What do you say about the scratches on the back? Are they in general enough to kill a board?

 

[Lafong]

I see your picture, but I'm not sure I see the scratches.

I would not assume they are the cause, pending more info.

I guess you have ordered another motherboard regardless.

50/50 likelihood on proper cooler mounting doesn't sound promising.

Paste...don't know how much you used. A blob the size of a BB pellet should be enough.....certainly no more than the volume of the eraser on a pencil or a common green pea.

I reckon the PC fails to start at all with a CPU because the CPU has immediate heat issues. Without the CPU it may stay in a running state because there is no CPU generating heat.

 

[Vithonill]

I see your picture, but I'm not sure I see the scratches.

I would not assume they are the cause, pending more info.

I guess you have ordered another motherboard regardless.

50/50 likelihood on proper cooler mounting doesn't sound promising.

Paste...don't know how much you used. A blob the size of a BB pellet should be enough.....certainly no more than the volume of the eraser on a pencil or a common green pea.

I reckon the PC will start up without a CPU but fails with a CPU is because the CPU has immediate heat issues.

You can see the scratches where the white circle is, I think I nicked it pretty good.

Since the board turns off after half a second I think the CPU never got any power and it was cool to the touch when I tried it yesterday, so I dont think the CPU is overheating. I had the fans loose but plugged into the CPU fan socket.

I did not use too much paste when I last mounted it, it was a pretty perfect amount.

 

[RAIDGoblin]

in my experience if you use too much paste it just makes a mess and squeezes out the side, it may effect cooling slightly, but the effects would only matter under high load, cutting out after half a second is pretty quick for a thermal problem, particularly if it's only trying to load bios

For this to be thermal you would have had to mount the cooler wrong so it was partly lifted off the CPU, and you should recognise this when you take it off from the pattern of the squished paste, it should look like a nice even thin layer

You can see the scratches where the white circle is, I think I nicked it pretty good.

your third and fourth picture just looks like paint damage, but your first and second picture, you have nicked it pretty good. I can see the fibres in the PCB, if there were any tracks on the outside layer under those scratches, they are cut. I wouldn't give that high chances of working. Can you see if any tracks are cut? Hopefully the new mobo will work for you, let us know

I'd also be concerned about the white residue on the board, it looks like liquid damage or burn marks? unless it is from cleaning with alcohol

it should not be that hard to get the back plate off a mobo, when they are stuck fast like that it can be a sign that it's been overheated, probably when your AIO failed, just for future reference you can use heat from a hairdryer to loosen the adhesive instead of using force

 

[80251]

Scratches in the PCB can definitely cut traces, although I've never had that problem, at least not yet.

Good luck w/the new motherboard.