Issues with RAM after repasting

Hi!

I've repasted both CPU and GPU of my Clevo P650 laptop, as I've done many times before.

After doing so two of the 4 memory banks won't work anymore.

I've tested each slot and they all work in the first or the fourth banks.

What could cause this? They worked fine before repasting.

Thank you!

 

Did you short them out with paste or is something loose with the solder for them? Take a photo and post it if you can't find the issue.

Usually they work in sets of 1/3 2/4 so, having 1 in each set working is a bit odd but, points to a pair in the middle adjacent to each other.

Have you tested with a single stick and then moving them to the next slot to see if it's the ram or the slot?

Since you know 1 & 4 work if you move 4 to 2 does it work or 1 to 3?

 

Hi!

Hi!

In the repasting process I didn't do anything in the banks or the sticks. Just in the same position they were before repasting.

As I have said before, I've tried each stick individually in the banks appear to work properly, and they all work fine.

If you see the attached image it says that the working "rows" are 2 and 3...

 

Hmm.. so, 1 & 4 aren't working when all of them are slotted?

1 & 4 work when 2 & 3 aren't in use?

They didn't get moved around when repasting things and then suddenly stopped being seen?

The BIOS might have a setting for XMP / dual channel that somehow got changed during the downtime while repasting. Try sticking the working modules in 1 & 3 for dual channel and then if that works add the other two to 2 & 4.

 

/0/e memory 16GiB System Memory
/0/e/0 memory DIMM [empty]
/0/e/1 memory 8GiB DIMM DDR4 Synchronous 3000 MHz (0.3 ns)
/0/e/2 memory DIMM [empty]
/0/e/3 memory 8GiB DIMM DDR4 Synchronous 3000 MHz (0.3 ns)

So, this is the output in Linux of my setup for the RAM slots showing them staggered for DC memory handling.

 

What is your past? are you using any liquid metal?

 

I didn't move anything while repasting.

In fact, memory sticks aren't close to CPU or GPU.

Tried moving the sticks to other banks unsuccessfully, the laptop won't turn on,z the only banks that work are 2 and 3, individually or at the same time.

The stock BIOS lacks of any RAM option...

And finally, the thermal paste I've used is indeed liquid metal paste.

Thank you.

 

Liquid metal paste is the reason behind destroying a lot of systems, very tiny drop even you can't see it, can damage something on the motherboard or around the CPU. I think what happened with you that one of the tow memory channels is damaged, that's why you can use only 2 slots. You can use some kind of magnifier tool to look deeply for any Liquid metal hidden somewhere, hope that can be cleaned before any permeant damage happen.

 

LM will cause shorts if it get on the PCB and moves around to circuits.

Since this is a RAM issue I suspect if the LM is the case cleaning and checking around the points of application would be a good start. Check around the RAM for any droplets as well.

Otherwise it's possible they just stopped working if you run the machine hard and then it cooled down when reapplying and the solder cracked during the contraction/expansion cycle.

 

This is almost 100% certainly you getting LM someplace it shouldn't be. Could be anything from around the RAM slots to inside the CPU socket itself. It only takes a faint residue of it touching something to mess up something. Even if you had it on your fingers and you wiped it off, it still leaves a stain of conductive doom, and if you then touched the PCB, that stain could most assuredly short something on the spot.