The laptop turns on and the power LED lights up but nothing appears on the screen. The external monitor also shown no video. Unplugging the laptop from AC power and removing the battery for a minute doesn’t help.

Possible cause:

1. Memory failure.
2. Motherboard failure.
3. Processor failure.

Possible troubleshooting steps and repair solution:

1. Try reconnecting memory modules.

Try removing memory modules one by one and test the laptop with each memory module separately. This way you can find the faulty memory module.

Try installing memory modules into different slots on the motherboard. If the laptop works with both modules in one slot, but not in the other slot, the second slot is bad.

If you have only one memory module installed, try replacing it with a known good module.

2. If reconnecting and replacing memory modules doesn’t help, most likely there is a problem with the motherboard.

3. Could be bad processor, but processor failures are very rare. The processor would be the last thing to blame.