Broken RAM slot?

So I've been have this problem with my late '08 MBP for about 2 weeks now. I turned it on one day and got the single beep, googled it, and apparently it means no RAM installed. So I removed the modules, blew out the slots with a compressed air can and re-installed, same issue.

I took it to an apple store near me and one of the "geniuses" there took it in the back for testing. He said that either one or both of my RAM modules were bad and that if I had the stock modules at home that I could install them so I could use it until I got new RAM. So I took it home and re-installed the stock MBP RAM and tried again, but I got the same result.

Then I installed each of the four modules one by one in the RAM slots. They all worked in the top slot, but none worked in the bottom slot at all. So I've been running with a single 4GB RAM module, but my computer is running so slow, I can't even move my cursor without getting the spinning beach ball of death!

Should it be running this slow with only one 4GB RAM chip? It never ran that slow when I had the stock 4GB of RAM installed. If anyone could help my figure this out, it would be amazing, thanks!

I had this happen with my mid-2009 MBP. Yes, one slot went bad and I was stuck with 4GB. This is the reason why I ended up selling the machine recently and bought something new - which I ordered today.

Anyway, when a slot goes bad, there is nothing you can do.

Bad RAM slots happen occasionally. Not much you can do about it other than deal with it or replace the logic board, which is an expensive repair. Most people will use the computer until they can't manage with the RAM limitations then replace the computer.