Cheyenne821 removed then reinserted one of a desktop PC's two RAM DDR sticks. Now the PC won't boot. Is the damage serious?
It might be. And you're going to have to open up the PC again to find out.
First, let's take a moment to talk about precautions. There are a few things you should have done before taking out the stick in the first place; if you didn't, it's all the more likely that you seriously damaged that PC. And either way, you should take these precautions now as you reopen your PC for a second time.
Turn off the computer and unplug its power cord. Then unplug everything else connected to it except the keyboard and mouse. Lay the PC flat on its side on a table. The put on your anti-static grounding strap and open the case.
Put on your what? A grounding strap is a bracelet that protects the electronics you're handling from your body's static electricity. It needs to be clipped to something grounded. It's always good to have one on when working inside your PC--especially with memory modules. Belkin sells one for about $6.
Once you're safely strapped down, remove or gently push aside (in the case of cables) anything blocking your view of the RAM slots.
Now that you're ready to work with RAM, what should you do to fix--or at least diagnose--the problem.
Check to see if the stick you removed is properly seated. If in doubt, remove it and try again. Don't force anything. If you line up the connector with the slot properly and push down gently, the brackets on the ends of the slot should snap into place. Plug in the monitor and power line and try booting.
If that doesn't fix the problem, unplug the power line and monitor and remove the RAM stick again. Try rebooting with the one stick left in there.
Does that solve the problem? If it does, replacing that RAM module should do. If it doesn't, you'll have to take your PC to a professional, and hope that the damage isn't too extensive.
My thanks to Junibob, Alchav21, and Coastie65 for their contributions in answering Cheyenne's original question on the Forum.