Greasy water in laptop’s DIMM slot


My wife was having dinner in front of (on top of) the laptop and she spilled some soup onto it, right above the touchpad. Almost all of the soup ended up in the upper DIMM slot which sits underneath the keyboard.

I took the laptop apart and I've managed to clean and dry everything other than the internals of the DIMM slot. The slot has a dense, comb-like structure of pins which holds the greasy water in, and I cannot disassemble the DIMM slot in order to clean it thoroughly.

When I turn on the laptop it detects all available RAM and it works normally for about 15-20 minutes, after which it turns off. When I try to turn it on again it emits 1-3-3-1 beeps which means "Bad DIMM or DIMM slot". If I then take out DIMM chips, wipe them and clean the slot with a toothbrush it works again for a short time. I suspect that when the laptop heats up the grease in the DIMM slot melts a bit and short-circuits some pins inside.

I was wondering would it work if I used WD-40 with a straw to fill the DIMM slot, and then dry it with paper towels and a fan? The WD-40 should dissolve the grease and it dries faster than water, I'm just not sure whether after drying it leaves any conductive residues which would cause a short circuit inside the slot. Or is there something else I can try? Any thoughts and ideas are appreciated.

Best Answer

When it comes to slots and other hard-to-reach places on electronic boards, I often use a combination of Isopropyl alcohol (IPA) cleaner and compressed air. It is easy to damage pins inside the slot by using toothbrush or a toothpick. Just spray it well with Isopropyl alcohol, give it a gentle wipe and then give it a good blast with compressed air aiming directly into the slot. You can repeat the operation more then one time to achieve better results. You can buy both IPA and compressed air cans from ebay relatively cheap.

In regard to your idea of using WD40. I don't advise you to do that. From WD40 page on wiki:

The long-term active ingredient is a non-volatile, viscous oil which remains on the surface, providing lubrication and protection from moisture

You don't want to lubricate connectors on your motherboard. Even though multiple sources on the Internet say that mineral oil contained in WD40 is not conductive and it is often used to clean contacts in automotive industry. It is not suitable for computers. You will get problems with dust and grease buildup on oiled contacts.

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