Question White boxes on display, on restart won't go past bios


Mar 28, 2017
Oldish pc. Win 7 pro on one side of partition, xp on other. Gpu is Saphire Radeon HD 4870 2g and Mobo is Asus n13219. Idk what psu.

Tried to open up Warframe, screen suddenly turned to blue and white checker board pattern. Was able to close game and restart PC, but still messed up, weird white boxes and lines. Shut down completely.

Waited many hours and started again, came on, same problem, but PC suddenly turned off. Opened up PC. Cleaned out much dust and dog hair I never knew was in there. Fist fulls of it. Used can of air, is now the cleanest it's ever been. PC starts now, but screen is still messed up and won't go past bios. Tried to reset bios to defaults, made it worse.

Very desperate to fix, important info and pics on PC plus can't afford a new PC.

Is it Mobo or gpu? Both? Cpu? Can I get cheap and compatible replacement?

Ty in advance.

Pic of screen.

Pic after resetting bios to default

NOTE: not a gaming PC, was just for surfing web, checking emails, and storing important docs and pics.

I was only curious to see if I could open Warframe long enough to give away some stuff since I don't play anymore, ended up breaking the PC for others.