I have a Dell M90 notebook computer.

 

Recently I've noticed the computer would pause for a second or two, then go right back to working. I didn't immediately pursue the cause.

 

Now it's getting to where the computer not only pauses, but when it does the screen goes black (like it has no power) for about 40 seconds. Although it looks like it has paused and the screen is black, the hard drive light continues to blink and show activity. Then it comes back on and quickly catches up to any keystrokes/mouse clicks I may have done through frustration while the screen was off.

 

This morning I woke up and moved my mouse to turn it on (I turn on the '1min monitor turn off' at night) but it didn't turn on. I turned it off and back on, and noticed during the Dell boot splash screen there were rows of dots all over the place. The dots were also over the Windows logo. It wouldn't boot normally, so I booted into safe mode. I went to Bitdefender and Panda Software and got two online scans. Both found viruses (Bitdefender finding the offending file) and cleaned it all up.  I was then able to reboot normally and work most of the day, but I just had another pause where the screen went dark/off.

 

Is there anything else I can do to diagnose what is causing this? It seems to be random, although it didn't happen while I was in safe mode.

 

-Matthew