Attempting to determine the cause of the issue...
Attempting to determine the cause of the issue...
I went through a lengthy process trying to upgrade my Corsair RM850e with an MSI MAG A850GL. The PC has been performing well with a 5080 for several weeks. Before this change, I almost forgot one of the six-pin water coolers and the machine would overheat the 9800X3D, forcing me to shut it down in panic. After replacing the power supply, things improved: first boot was smooth, temperatures stayed stable. During subsequent boots, the system froze—lights and fans were active but no output from the motherboard or 5080. Eventually, I reinstalled drivers and rebooted successfully. However, on later attempts, only the motherboard output worked without lag, and I detected the 5080. I had to reinstall everything and even reset the BIOS. The sixth and seventh tries ended in total failure. The eighth reboot brought it back into BIOS mode, but I manually set the GPU PCIe to 4x instead of 5x. It’s been hours of troubleshooting without any screen or update. I’m worried about damaging my CPU, but it seems the issue is with the GPU. My fans only spin briefly when powering on. I’m really stressed—this experience has made me hesitant to build a PC again. I was also concerned about the PSU, but the motherboard and 5080 are functioning normally. The Gigabyte AO motherboard code works fine.
No, only the power supply units were changed and all the cables were replaced.
I completely removed and reboxed the entire old PSU&cables before touching the new one. Everything was properly seated with a click. I’m noting that the old unit was 12VHPWR on both sides, which makes sense. The unusual boot behavior—twice opening Windows with many glitches—is what’s puzzling me.
It's odd, isn't it? Let me double-check all your cables just in case. I'll get back to you—this is 2 AM, so I'm not sure I'm thinking straight. I need some rest. Maybe others will help, but it's late for most, so more replies tomorrow should come. We'll sort this out.
Your GPU appears in the BIOS settings. Note: On the fifth boot you mentioned detection, so likely no problem there. Another chance is the Windows setup got damaged when you tried to restart it, though I've seen cases where systems overheat and power down during Windows installation without issues, so it's uncertain.
Consider disconnecting your GPU and connecting the monitor directly to the motherboard to test startup. If Windows fails but BIOS appears, try using a USB drive with the installation files. It might help identify corrupted boot files. For hardware issues, the CPU may reduce performance when overheating rather than fail immediately. Good luck!