Question RAM stopped working after cleaning PC ?

[Makatas]

I had 4x8GB ram in my pc. Took my pc apart for cleaning and after that it no longer works with 4x8. I tried all kinds of arrangements, like testing every ram stick solo in any of the slots etc. and the results were that it doesn't matter where i put the ram, pc works if i put 1 or 2 sticks in, but if i try to put 3 or 4 in, it no longer boots. Any ideas what i could have messed up here?

 

[Lutfij]

Remove all sticks of ram from your build, then use an eraser to wipe the gold contacts on the sticks of ram. Wipe clean off of any dirt or debris and then repopulate on the slots on your motherboard. Speaking of motherboard slots, you might want to take a fine bristle paint brush and clean the ram slots, before dropping in the rams in your build.
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When posting a thread of troubleshooting nature, it's customary to include your full system's specs. Please list the specs to your build like so:
CPU:
CPU cooler:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:
include the age of your PSU apart from it's make and model. Include the BIOS version for your motherboard as well.