Member Avatar for Mallorca17

Hello,
I am trying to troubleshoot an older PC that was working until today. It appears to boot up correctly (I can hear the windows welcome - after one long beep and three short beeps), but the screen remains blank and the green light on the monitor blinks repeatedly. When I plug the same monitor into my laptop, it works fine. When I unplug it from the PC, it says that there is no signal. Is there some simple reason why the PC doesn't seem to recognize the monitor now?
Thanks for any solutions.

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Dani AI

Generated

Brief summary and a focused troubleshooting path for 's symptom (PC appears to boot—Windows sound and POST beeps—but the monitor stays blank while the same display works on a laptop).

Start by confirming what the monitor itself sees: press the monitor's menu buttons to bring up the on‑screen display (OSD) and verify the input selection. If the OSD is visible, the panel/backlight is OK and the problem is that the PC is not delivering a usable video signal. If the OSD is missing even on a known-good monitor, suspect the monitor power or backlight (less likely here because the monitor works on the laptop).

Next, isolate software vs. firmware/hardware quickly. At boot press the BIOS key (Del/F2/F10 depending on the board) to check for a BIOS/POST screen. If the BIOS screen appears but Windows desktop does not, boot Windows into low-resolution mode (Advanced Boot Options → “Enable low-resolution video (640x480)” or Safe Mode) and uninstall/reinstall the graphics driver or lower the desktop refresh rate/resolution. If no BIOS/POST is ever visible on that display, the PC is not producing a compatible output before the OS loads.

Hardware checks to do after the above: inspect the graphics card area (visual signs like bulging capacitors or scorch marks), confirm any GPU auxiliary power leads from the PSU are connected, and try the PC’s other video outputs (VGA vs DVI/HDMI) or an alternate TV/monitor on the PC to rule out a single dead port. Clearing CMOS to restore video-related BIOS defaults can help when firmware settings have been corrupted.

These steps complement the earlier posts (thanks to , and for diagnostic direction and to / for confirming this recurs). Power off and unplug before opening the case. If the problem persists after the software checks and the visual inspections above, the likely next step is component-level testing (power supply or GPU replacement) or having the board examined by a shop.

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Member Avatar for dcc

The beeps are an error code, if you tell us what make and model your computer is we can find out what the error code is and go from the to sort out your porblem.

Member Avatar for halo1353

Hello,
I am trying to troubleshoot an older PC that was working until today. It appears to boot up correctly (I can hear the windows welcome - after one long beep and three short beeps), but the screen remains blank and the green light on the monitor blinks repeatedly. When I plug the same monitor into my laptop, it works fine. When I unplug it from the PC, it says that there is no signal. Is there some simple reason why the PC doesn't seem to recognize the monitor now?
Thanks for any solutions.

Try a different Vid card, if it's integrated, then go with the other soloution.

Member Avatar for hhpcandi

I am having a similar problem with my hp 1530 flatscreen monitor. Computer starts up fine, light on monitor blinks, but dark. I can vaguely read what in on monitor but my eyes are not what they used to be. I just bought monitor a little over a year ago, please help save it.

Member Avatar for ah24

i am getting the same problem

Member Avatar for PcTestCard.com

Try reseat the video card if the card is dedicated not onboard.

Check the monitor connection and the cable.

Hope this helps!
Bill
Tech Manager

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