I have a Dell Optiplex 790 tower that will not post. I get a 1-3-2 beep along with the #1 light lit up. According to the Dell website, this means that there are "No memory modules are detected".

I already tried reseating the ram, tried all four slots and every combination possible of those four slots. I tried taking one ram stick out and only having one in, then tried with just the other ram stick in and I get the same beep codes with just one and just the other.

I also tried clearing the PC of any residual power, tried clearing the CMOS, I also tried wiggling the heat sink, pretty much everything that I could come across scouring the internet. Same beep codes

I also tried using a can of compressed air to remove any dust that may be in there, and I shined a flash light in there and the slots are clean as can be. Same beep codes

I am at a loss here, the PC worked two weeks ago so I have no clue what the problem could be. I doubt both ram sticks would go bad at the same time—especially when it worked two weeks ago.

The light on the back is solid green.

Is there any other things I can do to fix this?