[SOLVED] Why HP desktop computer won't boot with a different GPU installed ?

[Kevva]

Hi! My girlfriend has a HP Pavillion from 2015 which is pretty trash for gaming (Radeon R5 GPU). So I am trying to install my old GPU (Radeon HD 7870) into this PC. I replaced the PSU with a 600W one, removed the old GPU, inserted the 7870 GPU along with pcie power cables and tried to boot. When trying to boot, I get continous beeping in pairs of three and it doesnt boot. If i try to boot without GPU or by putting the old GPU back in, the computer successfully boots.

I tried the new GPU on another motherboard but with the same PSU, and it successfully boots.

I tried putting the new GPU in the HP computer again, and still the same problem. I pulled the power cable and removed the CMOS battery for a couple of minutes, reinserted it and tried to boot again, same problem.

So, long story short, the HP computer works with the GPU it came with, and the Radeon R5 works in another setup. Do you guys have any idea what the problem could be or how to solve it?

 

[Lafong]

For what it's worth:

pavilion "3 short beeps" - Google Search

What does 3 beeps mean on a HP computer?

problem with the system memory

Three beeps that repeat after a pause and occur when you power on your computer indicate a problem with the system memory. Three beeps that play and then stop as the computer starts successfully mean that the BIOS was restored.Sep 8, 2020

 

[Kevva]

For what it's worth:

pavilion "3 short beeps" - Google Search

What does 3 beeps mean on a HP computer?

problem with the system memory

Three beeps that repeat after a pause and occur when you power on your computer indicate a problem with the system memory. Three beeps that play and then stop as the computer starts successfully mean that the BIOS was restored.Sep 8, 2020

Thank you for the response. To be more specific about the beep codes, it is three Long beeps in low pitch followed by three Short beeps in high pitch. This sequence of beeps repeat five times.

I tried to use another memory stick, without a GPU, and the computer started beeping 3 Long and 2 Short. I updated BIOS to latest version but to no avail. It seems like the computer doesnt accept any hardware that wasnt originally in it. Could it be something like that? Because it makes No Sense to me why it doesnt accept the other fully working RAM or the GPU...

 

[Kevva]

I disabled secure boot and enabled legacy mode, and now it works ☺️