Laptop often shuts off 5-30 seconds after starting 9/10 try

Laptop shuts off 5 to 30 seconds after startup, usually just as the four flag parts fly together as windows 7 boots up. Sometimes before that, or even when automatic repair is attempting to start after a few failed boots. If I keep trying it will usually boot after 9 or 12 tries and run fine until next time. . Any ideas, it is not the battery, or the software, as same hard drive boots fine if moved to another identical computer. I also replaced the processor and both memory sticks. The cooling gel on the processor is in good shape and fresh too. I made a video of the problem here: https://drive.google.com/open?id=1oeadiMYuwXWVKmkjKCzd-...

 

Based on what you have done so far, the problem is likely the (power supply) or motherboard. Assuming it occurs when connected via AC or when using the battery, then "power supply" would be the power circuit on the motherboard.

 

I think you have the answer. I thought something with the power supply at first and replaced that too...so it must be power supply on the mother board. IS there anything that can be done to try to identify the component and fix this, or does the board have to be replaced?

 

Sure, with schematics, proper test equipment, and a 3M or higher rated repair certification. And I'm sure anyone with those skills wouldn't be asking for help here. Your best bet would be a new motherboard, but depending on the age of the laptop, your money is likely better spent on a replacement.

 

Does it power off if you just go into the bios? Have you checked your temperatures to make sure they are in range? I would also test with a linux live usb such as mint.

Linux Mint
https://www.fosslinux.com/274/how-to-create-linux-mint-live-usb-drive-on-windows.htm