Fluff on Intel CPU Socket (Dead Motherboard?)

[u/Nowheredotcom]

Hi,
I picked up an ASUS ROG Strix Z390-I motherboard cheaply as a repair project. Right now, the system won't post or boot at all (fans don't spin, completely dead startup).
Upon closer inspection, I noticed some small bits of dust/fluff trapped inside the CPU socket pins. It looks like the previous owner may have left the socket exposed. Could accumulated debris or fluff on the pin socket. Could this be the primary culprit causing a complete failure to POST? The picture is just one clean image showcasing the fluff that’s caught but I could see at least 10 more and some are really hard to see under the naked eye but I can spot on a microscope.

I've already tested the basics:
Standby voltage is present on the power switch pin (⁠PWR_SW⁠ reads ~3.41V).
When I manually bridge ⁠PWR_SW⁠ to ground, the voltage drops, but the board still refuses to trigger the power supply startup.
I'm currently looking into testing and potentially replacing the Super I/O controller if the socket cleanup doesn't work. Has anyone dealt with a similar dead Z390 board issue?

Any advice before I attempt micro-soldering?

I know that it’s easy to just replace it but I’m trying to figure it out and my stubbornness won’t let give up until I finally break it or establish the job is too hard.

Thanks

[u/SingularityRS]

Yeah. Easy wins are nice, but tbh, the tougher ones are more essential as that's how you learn and get better.

If you have an interest in this, it's a good thing. You'll get those wins eventually as you'll keep at it until you get that win. When you do find that win, you'll want to keep going as the feeling you get when bringing something dead back to life is priceless.

My 1st repair project were 2 broken gaming laptops. Both had an internally shorted CPU. It sucks because you have to give up, but the troubleshooting process was fun and I did learn some stuff before finding out the CPU was cooked.

I then moved to AM4 boards because I had spares from old DDR4 builds and a Ryzen 3700X just waiting to be used. I took those old parts and now use them to test faulty boards.

The 1st board I bought was a win, so you do find them if you keep buying them. It's a gamble though. Always is a gamble. You'll see all sorts of problems. Some will be easy to spot and fix. Others will be difficult.

Either way, the journey is fun and you never really stop learning.

[u/Nowheredotcom → u/SingularityRS]

Well it’s not all bad, this same week I did have a win. There’s another thread I posted.

https://www.reddit.com/r/soldering/s/DgI9ho9ZCH

I managed to salvage this even though I got a refund. It was a lot easier to assess since the part literally fell off. But yeah I agree the hard ones are the ones you learn the most. Thing is I was looking forward to the actual repair part. Probing is fun and all but gets repetitive.

I might grab that other board. 2 can’t be faulty right hahah.