HP 840 G1 laptop wont start due to memory module issue

[Kocane]

I have this EliteBook 840 G1 laptop that won't start - it blinks on the caps- and numlock buttons 3 times which indicate issue with the memory modules. On one of the memory slots of the motherboard, I can see some corrosion (?) and my guess is that it's creating a short. At first I figured I could just omit using this slot but it wont start either way - also tried other RAM sticks of course.

I've tried to see if I could clean it up, but the laptop remains unbootable. Can it be because it has caused issue elsewhere or because it's still shorting in the memory module?

This is how it looked before and this is how it looks after my attempt to clean it.

Maybe I made it worse?

[Sephir0th]

Re: HP 840 G1 laptop wont start due to memory module issue

You need better tools to a) visualize the problem and b) check yourself.

From the second picture you shared, nobody can assume anything. With a multimeter you can perform simple checks, as Resistance to GND of the pins in question and Short circuit between the pins (in continuity mode). Then you could clarify which pins are affected exactly, since the module slots have all the same pinout (you can find out with random schematics of same RAM technology).

We can not perform your own homework here. Something you need to do by yourself.