Why did the RAM suddenly work?

Question

RAM

After being transported on the plane, 2 RAM sticks fell out: then one worked, and the second was not detected (I stuck it in all the slots in all possible ways, one at a time and both together), put it on a shelf.
After 4 months stuck, immediately everything was determined. How can this be explained?

Answer 1

Heat. The metal melted and contact was restored. :)
A joke, of course, but that's about it. Maybe something else is blocking the contact.

Answer 2

rather, something else closed where it was NOT necessary, and then it flew
away, my laptop did not turn on due to the fact that the case screws were not tightened, I often stuck my fingernail into the slot and the dirt from my nails accumulated in the area of ​​\u200b\u200bthe indicators.
turned on just when the dirt was removed

Answer 3

Did you reset or update the bios...