Hi! I have this issue that my above mentioned GPU wont work on top slot with PCIe GEN4 or AUTO mode, with GEN 3 it works. First time when i install the GPU to this slot system boots to dekstop but after 6 seconds or so screen goes black, restarts and does not post anymore. One thing to note that booting in safe mode the 4.0 works on the top slot. Swapping the gpu to slot 2 -> booting -> swapping back to slot 1 makes the above mentioned happen again. Boots to windows -> screen black -> restarts -> does not post Bottom slot works with GEN 4 and AUTO but i suspect this is due to the fact that its is PCIe_x16 @ 4lanes? Could this be PSU/cable issue. My XFX 550w is around 7 years old. Some things i have tried to fix this. Flashing bios the the latest Updating chipset drivers Reseting CMOS Reinstalled windows Purged my GPU drivers and reinstalled those Any ideas?