Why would your computer turn on but display a black screen?
There are a few possibilities:
1. Loose, unplugged, pinched, or failed video data or power cables.
2. Incorrect BIOS settings.
3. User error. A multiple video card computer may be sending data to the monitor you are not hooked up to.
4. Incorrect brightness settings on your monitor.
5. Failed/failing monitor hardware.
6. Failed/failing video card hardware. This can be part of your motherboard or a removable card.
7. Failed/failing power supply or supplies.
8. Bad operating system driver. However you often will see bios messages before going black on system boot.
9. PC and/or external monitor power supply damaged/malfunctioning.
10. Power supply not sufficient for all attached internal devices.
11. Dirty power. Too many spikes and brownouts.
12. Short in case. Generally caused by an extra screw or other debris in whitebox computers. Sometimes misdiagnosed as a bad case.
13. Malfunctioning or shut off UPS or surge strip, if attached.
14.It has no battery.(laptop)