Problem with HP Compaq 6720s

[ferguson1951]

Hello.
I have this old laptop that I repaired myself by replacing the faulty mobo with a working used one.
The laptop now works, but has a problem.
I cannot install an OS because halfway through the process it stalls.
If I'm using a DVD, it suddenly goes off and reboots again.
If I am using a bootable USB key it gets stuck half-way though the process and stays blocked on that page for a while and then reboots.
What do you think? Is it a software or hardware problem?
Thanks a lot and best regards

 

[Lutfij]

I think it's a hardware problem whereby power might be cut off or that the drivers for the process are lacking. Speaking of drivers, what OS are you trying to install on your drive? Can you get into BIOS and remain there without an issue or does it shut off abruptly?

 

[ferguson1951]

I have tried at least a dozen Linux distributions. Starting from Ubuntu 14.04 and going down to the lightest ones. No success. The Live Linux is held unchanged but I cannot install anything. I can access the Bios with no problem and held it on for 15 minutes but in the end it was showing some lines on the writing as if the video card was not working properly. But then I cannot leave the Bios by pressing esc because the page is stuck. I do not think the laptop is overheating. I have worked on other laptops of the same model with no problem. What kind of hardware problem do you think it is?