Compaq Beep Code

Beep codes common to HP and Compaq Desktop PCs
The following beep codes are common to many HP and Compaq desktop computers. Use these codes first before referring to the other code lists.
   

1 short beep and 1 long beep    Memory problem
2 short beeps and 1 long beep (repeats 5 times)    Unable to initialize video or video card required but not installed
3 short beeps and 1 long beep    CPU

Blank Screen Error Code In Compaq

The LED lights near the Caps Lock and Num Lock keys will blink if an error is detected during the start up process. The LEDs will blink a number of times in a sequence and then stop. The number of blinks in the sequence indicates what component caused an error when it was being tested during start up.
If the LEDs stop blinking and the computer does not start, you can press the power button again

Toshiba Satellite A305 Restart or Freeze

If you have a toshiba satellite a305 hang or restart when power adapter is plugged. It may be NEC/TOKIN faulty. Try this one:

 This may work fine on other laptops with same problem