Situation 3
When you press on the power button, the laptop makes a series or short and long beeps and will not start up. There is no video on the screen.
In this situation test the memory module as I described in the situation2. Try installing a known good memory module. Most likely you are getting a beep error because of a faulty memory.
Situation 4
You start the laptop. It sounds like the laptop is booting normally (hard drive LED is flashing) but there is no video on the screen
In this situation test the laptop with an external monitor. If the external screen works fine but there is no video on the laptop LCD, most likely there is a problem inside the laptop display assembly.
Situation 5
You start the laptop and it starts making repetitive clicking noise or grinding noise.
Most likely you hear this noise because of a faulty hard drive. You can remove the hard drive and start the laptop without it. If the noise is gone, the hard drive is your problem. Replace it.
If the laptop makes clicking or grinding noises and you still have video on the screen, you can run a hard drive test utility. I usually use Hitachi’s drive fitness test. This test is reliable and easy to use.
Situation 6
The laptop boots into Windows and works for a while, but after that it shuts down by itself without any reason or warning. You restart the laptop but the same problem appears again
Most likely it’s a heat related issue. Listen for the cooling fan, make sure it works.
Also this problem might appear because of a faulty memory module, try some tips from the situation 2.
The laptop still boots and you still can see the screen, so you can run the memory test. I usually use Memtest86+. Run the memory test and if it fails, replace the faulty module.
Situation 6
The laptop starts normally but video on the screen has lines, some strange characters or other defects
It could indicate a problem with the laptop LCD screen, video cable, graphics card or motherboard. Here’s my previous post witch covers troubleshooting bad images on the screen in more details. Click on the link below: