No display after replacing PSU – RX 6600 XT, monitor detects DP cable but goes into power saving
Hi everyone,
I'm having an issue after replacing my PSU and I'm running out of ideas.
PC Specs:
- CPU: AMD Ryzen 5 3600
- GPU: AMD Radeon RX 6600 XT (1x 8-pin PCIe)
- Motherboard: B450M
- New PSU: Silverstone strider 650W 80+ rating bronze
Background:
About a week ago, my PC was working perfectly. Then my old PSU failed, so I replaced it with a new non-modular PSU. Since then, I haven't been able to get any display.
Symptoms:
- The monitor detects when the DisplayPort cable is plugged into the GPU.
- If I unplug the DP cable from the GPU, the monitor says something like "Waiting 5 minutes for you to connect the DP cable."
- When I plug it back into the GPU, the monitor immediately goes into Power Saving Mode.
- So the monitor seems to detect the cable, but it never receives a video signal.
What I've already tried:
- Reseated the GPU.
- Tried both 8-pin connectors on the PCIe cable (it's one cable that splits into two 6+2 connectors).
- Confirmed I'm using the PCIe cable, not the CPU/EPS cable.
- Checked that the GPU power connector is fully inserted.
- CPU fan, case fans, motherboard lights, keyboard, and mouse all power on normally.
- The GPU fans do not spin during boot, but they briefly twitch when I turn the PC off.
Since the Ryzen 5 3600 doesn't have integrated graphics, I can't test through the motherboard video output.
At this point, I'm wondering if:
- the GPU was damaged when the old PSU failed,
- there's still a power issue,
- or something else is preventing POST.
Does anyone have suggestions for what I should test next? Thanks!