Solved mobo issue?

[donthackidss]

did some cleaning yesterday. pulled fans apart to clean them out, added a new sata, replaced thermal paste etc. after finishing i plug it in and turn it on, but it doesn't display anything. here's pretty much what happens:
sometimes when first turning on it shuts off after a brief second. when booting it again, everything runs for a second or two, but then all but external fans stops (this morning cpu fan stays turned on as well). gpu rgb works, even though the fans dont. There's no MB error lights, tried all the ram configurations (pretty sure both ram sticks work, dont have another system to check on though). Another strange thing is this yellow underglow of the motherboard (for context, i have a prime z490-p paired with a 10700k) which before only appeared while the pc was in sleep mode.
I esentially have no idea to even troubleshoot this. Any suggestion is greatly appreciated. I can provide pics if needed.

 

[veeg]

Hello

How much paste did you put on ?

 

[donthackidss]

thermal paste is fine, it leaked just a little but didn't get into the cpu socket. Also removed the cooler to check and it looked in order.

 

[PeterOz]

reset the cmos - short pins
Page 1-17 https://dlcdnets.asus.com/pub/ASUS/...PRIME_Z490-P_UM_V3_WEB.pdf?model=PRIME Z490-P
or remove power cord press on /off button a couple of times remove cmos battery 10mins
Battery back in, power back in
test

thermal paste is fine, it leaked just a little

I disagree any leak is not fine
There should never be so much paste that it can leak.

 

[phillpower2]

Was just about to post at the same time as Peter so a bit of repetition.

Thermal compound does not have to get into the socket to short the board out.

Another strange thing is this yellow underglow of the motherboard

Where are you seeing this yellow underglow.

Can I just make sure that you have a working keyboard attached to the PC.

Also removed the cooler to check and it looked in order.

After doing this check did you repeat the cleaning off properly of the thermal compound and then applying a fresh amount, if yes, describe how and what you used for the cleaning and application.

Please post the brand and model name or number for the RAM ( including the amount, number of sticks and speed ) add on video card and the PSU (power supply unit) .

 

[donthackidss]

After doing this check did you repeat the cleaning off properly of the thermal compound and then applying a fresh amount, if yes, describe how and what you used for the cleaning and application.

Here's the spec list:
i5-10700K
Prime Z490-P
RTX 3070 Ti
2x16 gig (https://www.adata.com/upload/downloadfile/datasheet_xpg_hunter_ddr4_u_dimm_20210517.pdf , these seem to be the ones)
the PSU seems to be an NJOY 750W 80+ Gold

This is a pre-built I bought 2.5 years ago. A month or two ago I noticed CPU temps were constantly at 90C+, and so I thought I should replace the thermal paste. Considering the reply, I'll assume I made a mistake by not reapplying thermal paste after removing the cooler once again to check.

I should mention the yellow glow is by no means an error light such as DRAM, it's just something that's not supposed to be there.

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The video is taken while the pc is on. You can notice the cooler rgb is on, but dimmed (it only does this normally while in sleep mode, same as the underglow) You may also notice the ext fans aren't working: I disconnected them to be able to manage the cables easier and to check if there's any cables not plugged in properly. During this I noticed the metal part of the SATA cable going into my HDD fell off the cable and got stuck in the hard drive (I removed it). I think and hope that's a different part of the story and doesn't have anything to do with the booting issue.

I'm certain it's not recognizing anything plugged into any of the USB ports. I tried multiple keyboards and a mouse, all of which should light up as soon as the pc turns on.

Considering you both emphasized the thermal paste issue, should I clean it up (I used ~99% isopropyl) and reapply or is it possible the first time it just destroyed the board?

 

[phillpower2]

the PSU seems to be an NJOY 750W 80+ Gold

So bad that it needs to have the cable cut off it before it being tossed in the trash, see related thread here

I'll assume I made a mistake by not reapplying thermal paste after removing the cooler once again to check.

100% correct there and fwiw when applied correctly good quality thermal compound will never need to be replaced and most often lasts the lifetime of the computer.

I'm certain it's not recognizing anything plugged into any of the USB ports. I tried multiple keyboards and a mouse, all of which should light up as soon as the pc turns on.

Not sounding too promising and especially after reading that something metallic fell off and landed inside of the computer.

It would be helpful if you had a wired PS/2 type keyboard that you could try.

At this point I would be suggesting you start asking around to see if you can borrow a PSU to swap in for testing purposes, if you were to remove the add on GPU from the MB altogether and hook up the appropriate video port on the MB to the screen you will get away with any good quality brand 500W PSU for testing the system with no add on GPU involved.

The thermal compound we need to come back to.

 

[donthackidss]

Regarding the broken cable: I might have used some rough wording. The metal bit never actually fell. It was the rest of the cable that got disconnected and the metal bit remained inside the hard drive. Essentially what I'm asking is if it's safe to rule out a possible short circuit of the broken SATA cable (that is if it's even possible, I'm saying this with my extremely superficial level of electronics knowledge) that's the cause of the misbooting.

I doubt I could find a PS/2 keyboard anytime soon, but even so, what help would it have if at no point it displays anything? Or is that presuming I'm using a different PSU?

Anyhow, I could borrow the PSU of my relative and do some testing tonight. If i understood correctly, should I keep only the vitals connected and try to boot it up so? Or should I change out the thermal paste first? The paste I used is an MX-4 Thermal paste that came with the arctic cpu cooler of the pc of said relative. Also let me know if it's wrong or not using "old" thermal paste.

 

[phillpower2]

Regarding the broken cable: I might have used some rough wording. The metal bit never actually fell. It was the rest of the cable that got disconnected and the metal bit remained inside the hard drive. Essentially what I'm asking is if it's safe to rule out a possible short circuit of the broken SATA cable (that is if it's even possible, I'm saying this with my extremely superficial level of electronics knowledge) that's the cause of the misbooting.

I merely replied to what you post, if you tell us that something metallic fell that is all that we have to go on.

I doubt I could find a PS/2 keyboard anytime soon, but even so, what help would it have if at no point it displays anything? Or is that presuming I'm using a different PSU?

If you don`t have a working keyboard hooked up the power on self test ( POST ) will fail when the BIOS fails to detect it, this regardless of you having a good quality appropriate spec PSU.

Anyhow, I could borrow the PSU of my relative and do some testing tonight. If i understood correctly, should I keep only the vitals connected

You need to do exactly as advised and provide all required feedback.

describe how and what you used for the cleaning and application.

You never told us how you cleaned off the old compound only that you used 99% isopropyl) + you likewise never told us how you applied the new thermal compound, the fact that it spread onto the MB suggests that it was not done correctly.

How did you clean off the old compound and how was the new stuff applied.

Also let me know if it's wrong or not using "old" thermal paste.

Sorry but no idea what you mean.

 

[donthackidss]

At this point I would be suggesting you start asking around to see if you can borrow a PSU to swap in for testing purposes, if you were to remove the add on GPU from the MB altogether and hook up the appropriate video port on the MB to the screen you will get away with any good quality brand 500W PSU for testing the system with no add on GPU involved.

This is the testing that's not clear to me. Should I just boot it on after swapping out the PSU and removing the GPU and see what happens?

You never told us how you cleaned off the old compound only that you used 99% isopropyl) + you likewise never told us how you applied the new thermal compound, the fact that it spread onto the MB suggests that it was not done correctly.

How did you clean off the old compound and how was the new stuff applied.

Removed the cooler, cleaned the thermal paste off the conductive part of the cooler with a microfiber cloth that's been sprayed with some isopropyl alc and did the same with the CPU (at no point did I remove the CPU when cleaning). When reapplying, I put a very thin layer of thermal paste on the center of the CPU, leaving a ~2mm gap in-between the thermal paste and the edge of the CPU. Afterwards, I reinstalled the cooler and that's about it.

Also let me know if it's wrong or not using "old" thermal paste.

The thermal paste tube had been opened a year prior. I assume it's fine to use.

 

[phillpower2]

We now know that the thermal compound cleaning and reapplication was a mess so best to address this first.

The age of the thermal compound is fine but the cleaning off and reapplication not so.

To clean off you use the 99% isopropyl and either coffee filter papers or a lint free cloth, anything else leave fibres behind that cause air pockets, the compound that you used should have been a pea sized amount applied directly in the centre of the CPU.

As it stands you are looking at having to do the below;

Get yourself a P/S 2 keyboard if you can.

Borrow a PSU.

Remove the present PSU.

Remove the add on video card from the PCI-E slot on the MB,

Remove the CPU cooler, properly clean off and reapply the correct amount of MX in the centro of the CPU, when mounting the cooler do not wiggle or rock side to side the heatsink else it will cause air pockets.

Fit the test PSU.

Make sure that the RAM and connections to the MB are secure,

Make sure that you have connected the CPU cooling fan to the correct header on the MB.

Connect the screen to the appropriate videoport on the MB.

Connect the keyboard.

Connect the PSU to the power outlet, press the case power on button.

Post back with an update for us.

 

[Bruce]

And this all may be made easier if you remove everything from the case and reassemble on a piece of cardboard on a table.
This will not only allow easy access to all components but also give you the opportunity to inspect (and clean) each part as you disassemble and reassemble.

 

[donthackidss]

Will do. I'll be back in the next couple of days with an update

 

[phillpower2]

 

[donthackidss]

It worked. It was most likely a problem with the thermal paste, as you said. Ran into bios with perfect temps. After using the borrowed PSU (RM650) and seeing it worked just fine I swapped it back to the NJOY, which also worked. Considering your "disliking" of the NJOY, I'll get it swapped out soon for a better PSU, even though it was not the problem.
Right now I'll be placing everything back into the case. I'll be back as soon as I finish and make sure everything's up and running. Thanks to all of you for the tips. Thinking I put the thermal paste wrong would have been one of my last ideas.

 

[phillpower2]

Considering your "disliking" of the NJOY, I'll get it swapped out soon for a better PSU, even though it was not the problem.

Not a case of me disliking the PSU but to say that it is garbage would be an understatement, there is one thing that is possibly worse than using a known poor quality brand of PSU and that is using one that is unheard of, for brands of PSU to trust and brands to avoid please refer to the links in my sig.

Cheap PSUs exploding when being properly tested

Jonny Guru video

 

[phillpower2]

Post separately so that no one is under any illusion as to just how bad the present PSU and the emphasis that has been put on this;

the PSU seems to be an NJOY 750W 80+ Gold

So bad that it needs to have the cable cut off it before it being tossed in the trash, see related thread here

The below is from the accepted answer at the link in my reply #2;

The psu is the single most important component in any pc. It has direct voltage ties to everything. If you needed a new heart, if given the choice would you really get the new heart from a 90yr old alcoholic chain smoker just because it's a few € cheaper?

Even when out of the box new the PSU could not produce the minimum of 750W that your GPU requires.

 

[donthackidss]

Even when out of the box new the PSU could not produce the minimum of 750W that your GPU requires.

Understood boss

Anyhow, everything is running as it should be. Thanks a bunch again

 

[phillpower2]

You are welcome and thanks for the follow up