zapper, I thought we were going in that direction. One can literally sense the fear in my post above. Fortunately, resetting BIOS solved everything!

You may need to do external flashing, which I have almost no experience with, or... you could ask rachad for help like you are doing.

But he may need more info on the exact situation. I wish you the best on getting it working again.

now you should reinstall grub manually from a bootable usb if its not detecting it make sure your bios settings are correctly set to allow you booting, inside the bios u should find the right devices list that are set to be booting from, play arround and u will find it.

chrooting into ur system with the help of a live system from the usb drive fix grub and all should be back.

as for coreboot i have no idea if ur device can be flashed ask there in IRC or check the list of supported devices in there website.
good luck sagar

My display wasn't working, fan used to start but there was no display. So I took the matter into my own hands and started checking the voltages of motherboard components.

The last time my laptop was on was before the power completely drained out and it switched off due to low power, not software, but hardware switch off.

I removed the CMOS to check it's voltage and it reset BIOS. Now HP Pavilion has some sort of checksum checking and the default BIOS is pretty outdated. Also, there's no BIOS update prompt from which perhaps I could update BIOS using a flash drive.

Surprisingly after I reset BIOS, the screen lit up! but it couldn't detect the OS. Not even the perfectly good bootable USB trisquel. Apparently, the last person repairing my motherboard messed something with BIOS!

Help needed man.

If possible I'd like to go to something like coreboot, if there's some bios ic replacement which can do such a thing and if I can disable hp bios checksum check.