I have a HP Pavilion AMD Athlon Processor 550, Model 8662-C. It had 128 MB 
RAM.
I added another 128. While putting the memory in I disconnected the processor 
fan.
When I rebooted the machine it went through the starting post and said that 
the fan was disconnected and see a technician immediately. I immediately 
turned it off and plugged the fan back in. Then when I rebooted the blue HP 
screen comes up. The yellow light is on and it stays on a long time, and then 
it goes to a blank screen with a blinking cursor in the top left corner. If I 
press escape while the blue screen is on, it will take me to a screen that 
tells the type BIOS, then it goes through and checks the memory and it all 
passes, BIOS and video is shadowed. Then UMB upper limit segment address 
E966. Then it recognizes the fixed disk the CD writer and the dvd player. 
Press F 1 to enter setup. If you don't press F 1 it brings up a boot menu.
Enter to select a boot device, choices are removable drive, hard disk, CD, or 
network. Enter to accept or exit. No matter which one you enter it takes you 
to the black screen with the blinking cursor. What could possibly be the 
problem? When I take the added memory out, nothing comes up on the monitor.

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