Pc won't boot, no beep, amber light on mobo, hdd spins up, dvd drawer works and light comes on,fans working, no activity from monitor but I know its ok, hdd light on steady, all this for about 10seconds then all shuts down. Any ideas? Pull, wait, then re-install cmos battery? Psu failure?
For starters, eliminate all peripherals by disconnecting power to all drives, so only the motherboard, CPU and memory is left powered up. Then try again.
If the system now stays on, the problem is with one of the drives.
If it still fails, carefully remove the memory and try again. You should now only be powering up the motherboard and CPU. Again, if it still fails, you've narrowed it down to the heart of the system and the power supply.
The only way you can further check it, is via substitution, or if you have specialist diagnostic kit.
At that point, it could be the power supply being low on one of the power lines, or sadly, it's time to invest in a new motherboard and CPU.
I had similar problem as yours on 15th March I had delayed loading the normal MS update until 14th. PC ok when shut down next day as you describe. I could not sort it at all, tried all the normal stuff like reseating memory etc, could not even get it to boot into safe mode. Required reinstall to sort it.
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