Question PC won't load into windows 10 when new GPU is installed


Oct 29, 2020
I bought a Galax GTX 1060 6GB from a relative a few days ago. I know for a fact that it isn't defective because I was using his computer with the exact GPU installed in it, prior to him upgrading to a stronger GPU later that day, but anyways:

I installed the 1060 in my computer (specs at the bottom), upgrading from an Inno3D GTX 760 2GB that died last month, but when I try to turn my computer on, it gets stuck at the motherboard vendor splash screen (now it shows the AMI screen after resetting the CMOS) and just keeps beeping once every minute (like my old GPU did, except it actually loads into Windows after a while), then eventually my monitor just says "No Signal" and there's no hard drive activity shown on my case HDD LED.
Also my monitor is connected to one of the DVI-D ports of the GPU, and it is displaying from it.
Yes, I did make sure to uninstall the old 760 drivers with DDU.

I suspect that it's an issue with my motherboard BIOS as it's an old and OEM-"customised" BIOS. (I forgot the BIOS version.)

computer specs:
Processor: Intel i5-3570
Motherboard: Pegatron IPXSB-H61
Memory: Adata 8x2GB 1600MHz DDR3 (but one of the ram slots are dead)
Storage: WD Blue 500GB 7200RPM hard disk drive
Power Supply: Micronics Caslon BTC "700W" (i will eventually replace this crapbox with something more reliable and new.)


yep, it boots just fine with the integrated graphics.
I am aware there is some divide where old/new hardware won't work together in regard to GPU and motherboard but not very read in where that divide is. I have utilized GPU such as the 7xx and 9xx series with CPU as old as 2nd gen. I wouldn't (think) that a 3rd gen couldn't run a 10xx series GPU. My immediate thought would be that the failure point may be your PSU.
Have you tried testing the old 7 series on another working PC with an appropriate PSU?