PC won't boot only turns on with a memory in the first slot

Hello,
My PC has a strange behavior, recently I did a cleaning because it had too much dirt, I clean all the mobo and I put thermal paste to the cpu. The problem is that after this, when I turned it on I realized that it only turns on with a memory in the first slot. The second slot for some reason doesn't work, and if I put a memory there, the pc turns on and off in an infinite loop. Analyzing I think the problem could be some bent pin of the mobo. Here is a picture of the 4 pins that I suspect are bent.

Mobo: Asus H81M-K

Is that the problem, or is it normal? Thank you very much!