Received signal on both monitors, tried numerous solutions but unsure of the issue with my PC.
Received signal on both monitors, tried numerous solutions but unsure of the issue with my PC.
Hello everyone!
I’m facing a tricky issue I’m not sure how to fix.
After taking a nap, when I came back my computer was running but the screens were black.
I forced a reboot, but the screens stayed dark (it shows no signal).
I’m pretty sure it wasn’t both screens failing at once—I even used a third screen.
My CPU doesn’t have built-in graphics.
I own a Radeon Challenger RX 5700 as a video card.
I’ve tested various (but quite old) graphics cards—Radeon R580 and an XFX 7800 still produce black screens.
However, I’m not entirely confident these older cards are functional anymore.
I’ve also tried a different PCI slot, but without success.
What’s unusual is that I expect the system to boot into Windows login screen even if the monitor isn’t working, but there’s no sound (Windows 11).
I’m wondering if I should hear any sounds when I type in the wrong password and press enter.
Anyone have suggestions or resources to check?
Thanks in advance.
It is difficult to confirm with certainty, but the power supply might have failed.
Could you attempt using the monitors on another device? If you possess a router with administrative privileges and another machine, you might review the DHCP logs to determine if an address was requested—this would suggest the system is booting, though the display is not working. This differs from cases where no address was requested.
If you cannot test the monitors on another computer, I believe a power supply tester would be a reasonable next step (ensuring it matches your hardware requirements).
Visiting a local service center could also be an option, as they might offer to test the power supply for you or provide a replacement.
tx!
i plan to look into this.
i own a macbook and ordered a usb-c to display port adapter so i can check the monitors on monday.
unfortunately, i’m having trouble finding my old power supply.
i’m fairly sure i have a lifetime warranty on this one though.
evga supernova 750 if i recall correctly
another question, just to clarify how the PSU CPU fan operates—lights are on and even GPU fans are active, though oddly enough one of the older GPUs had only one fan working. This might be due to the card being very old or possibly damaged. Is this enough proof that the PSU is functioning properly? I’m checking PSU testers, which cost around 15 euros, so I might order one and hope it arrives by Monday.
I have no idea why, but my computer is showing screens again and I've logged in. I think I might have a general idea of what happened, though. Heh. Any suggestions would be helpful. Maybe there are diagnostics or something to check?
Computer power supplies contain several power rails including +3.3V, +5V, +12V, and -12V. Each rail operates independently, so components like fans can continue functioning even when the main logic fails ("lights on but no one is home").
Also, power supplies often provide multiple ports or cables at the same voltage, such as several +5V connections feeding into one supply, or separate +5V sources. Merging currents from the same source doesn’t increase available power, whereas combining currents from different rails increases supply capacity. Connecting the incorrect pair causes overload and failure, but pairing the right ones restores operation (though this is rare in typical setups). It highlights how complex computer PSUs are and how crucial proper connections are when troubleshooting failures.
Tx! That was really helpful and great to learn from. Thanks for spending the time to write that out!