Antwort auf „Why is my pc's screen black when I turn it on?”Hello guys, i had the same problem. But i went one step further. I bought a new unused MB and i replaced the old one. The screen still remained black. I cleared the cmos by removing the battery and changing the pins of the jumper and still nothing. While i was ready to give up, i looked more carefully the cpu which was "glued" with the heatsink and i spotted out that there was a slack between the cpu and and the cpu holder mount of the MB. I removed the cpu from the heatsink (just google how to remove cpu which is fused to the heatsink) installed it correctly and replaced the thermal paste. It worked like a charm. To make a conclusion, before you buy a new MB, remove the cpu from the heatsink, replace the thermal paste and check if it works.