Question regarding stained RAM chip

sandemonium · 30 May 2021 at 10:20

Hi, I recently purchased a used laptop and after a couple of days' use without problems, then I started to get a flickering screen and random freezes. I checked the RAM chips were seated properly and ran memtest86, which completed one full pass without errors. I did notice a stain on one of the RAM chips when initially checking them.

About 24 hours after the initial flickering/freezes (during which the laptop functioning fine) the flickering/freezing occurred again, but this time the laptop eventually wouldn't switch back on. The blinking lights (it's a Dell) indicated RAM failure.

I've now removed the stained RAM chip and the laptop's functioning fine again. I'm just wondering if anyone can identify the cause of the stain on this RAM chip? Could this be a sign of overheating, the chip being badly seated, or some other cause?

Thekwango · 30 May 2021 at 10:24

Blown/dying capacitor leaking oil maybe?

sandemonium · 30 May 2021 at 12:35

Thekwango said:
Blown/dying capacitor leaking oil maybe?

Thanks, would you care to speculate on a possible/probable cause of a blown capacitor? I'm trying to establish whether or not another hardware problem might be the ultimate cause.

demusss · 30 May 2021 at 13:04

Could it have been some liquid that was spilled on the laptop and has gotten under the coating at the edge of the board.
Are there any vents on the case near the ram board?

sandemonium · 30 May 2021 at 14:56

demusss said:
Could it have been some liquid that was spilled on the laptop and has gotten under the coating at the edge of the board.
Are there any vents on the case near the ram board?

There doesn't seem to be any evidence of liquid on the inside of the casing or on any of the other components. There aren't vents directly covering the RAM chips. I can see from the BIOS that the RAM was upgraded the day before the laptop was sent to me, so it's possible that a spillage occurred on another laptop and the seller attempted to reuse/salvage the RAM chip. Thanks for your thoughts.

tyler_jrb · 30 May 2021 at 18:47

Likely liquid. Have seen it quite a few times with water and battery acid leakage on pcb's over time they work their way under the mask, corroding the metal underneath. Bit like rust under paint.

sandemonium · 31 May 2021 at 12:33

tyler_jrb said:
Likely liquid. Have seen it quite a few times with water and battery acid leakage on pcb's over time they work their way under the mask, corroding the metal underneath. Bit like rust under paint.

Thanks, I'll order a replacement chip and will see how that fares. There have been no freezes or problems with the laptop since removing the chip, so it's likely that the chip caused the freezing and static screen, despite passing memtest86.