Question PC not POSTing with new GPU installed

[PetarS1]

My newly bought used RX 570 4GB will, when installed and connected, make my PC not POST, does not even show motherboard splash screen. My specs are: i5 2500, Intel DH67BL with BIOS BLH6710H.86A.0122.2011.0601.1554, 2x4GB Hynnix DDR3 1600Mhz RAM at 1333Mhz, an unbranded SATA SSD with 480GB, pretty fast one at that, a 320GB WDBlue 8MB cache HDD, and a PSU Rhino RX-550PA 550W, 466W peak on 12V rail i think, 190W continuous on that same 12V Rail. Last GPU is an XFX RX 560 2GB. The newly bought GPU with an 8pin will not boot in my PC. No POST, no nothing. My RX 560 2GB still works fine, it has a 6pin. I tought it was power delivery and PSU is not delivering enough power over the 8pin for the 570, but the 560 which never went over 70W in gaming and stress tests gets enough power. I brought a PC to one private shop owner who happens to repair PCs, and we tried it with a better 600W PSU. Still the same result. Motherboard also did not beep, like it does with no RAM on boot. The card has been tried in another system, works just fine, tried FurMark on 2 mins to see the perf, no artefacts, not hotter than 70-ish degrees C. It did show a few artefacts on boot, before the drivers loaded, yet on the screen with white dots spinning that appears before windows boots, when drivers seem to load, screen went from pure green to normal. Another RX 570 4gb with 8pin but of different manufact. was tried, no POST. An RX 580 4GB with an 8pin was tried too, no POST. We, at last, came to the conclusion that it was my PC not being compatible with the GPU, which seems odd. Now I am typing this with my 560 untill i can get the 570 to work and get a new PSU for it. Help would be greatly appreciated, as i do not want to, even though i can, sell the GPU (bought used, non-opened for 95EUR, and sell it for about like 130EUR, considering there are 2 or 3 of like 8 ppl selling the same model for 255EUR too). I have also posted this in many other forums, and so far the ppl are doubting that it still is power being the problem, or lack of it.

 

[DRagor]

We talking about this piece of door stop?