Member Avatar for kelly.worsnop

Hi ther ive got a compaq pc n when I turn the computer on the monitor cums on all black with the words vdu no signal monitor goin to sleep thats all it does can u help m find out what the problem is

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Original poster describes a Compaq where the display powers up but immediately reports no video and returns to sleep. That pattern usually means the monitor has power but isn’t seeing a valid sync from the PC. The cause can be trivial (wrong input, bad cable) or a hardware fault inside the machine (video card, motherboard, or PSU).

As suggested, start by confirming the monitor itself: bring up the monitor’s on‑screen menu — if the menu appears the LCD electronics and backlight are working, so focus shifts to the PC or the cable/adapter. Verify the monitor input selector matches the cable (VGA/DVI/HDMI), swap the cable for a known good one, and — where possible — try the monitor on a different computer or try a different monitor on the Compaq. Inspect connectors for bent pins and any adapters (DVI→VGA, HDMI→DVI) that could break the signal chain.

If the monitor is fine, look to the PC: note whether fans spin, whether the HDD/activity LED blinks, and whether keyboard LEDs toggle when NumLock/CapsLock are pressed — these are passive indicators of POST/OS activity. Listen for BIOS beep codes (or check motherboard diagnostic LEDs) and try to access the BIOS/UEFI screen. With the power off and unplugged, reseat the RAM and any discrete GPU, or move the video cable to the motherboard’s video output if a discrete card is present (some boards disable onboard video when a PCIe card is installed). A clear, minimal‑hardware boot (CPU, one RAM stick, GPU if needed, no drives) helps isolate a faulty component.

Common failures are a dead/disconnected GPU, a PSU rail that won’t feed the graphics card, or a motherboard fault. Useful diagnostic details to record are the machine model, whether a discrete GPU is fitted, the exact cable type, HDD activity behavior, and any POST beep pattern — these make further diagnosis faster and more accurate. Grounding precautions and unplugging power before opening the case are recommended.

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Member Avatar for kelly.worsnop

Hey ther can u help m sort my boys pc the monitor cums on all black n gors straight into monitor going to sleep mode

Member Avatar for caperjack

hi,sometimes it not a issue with the monitor ,but an issue with the computer ,maybe the video device in the pc is not working ,maybe the computer itself is not working ,like windows is not even starting up when you turn it on ,many ways to troubleshoot this ,first one is try another monitor ,i know not all of us have 2 of them but a lot do ,
does it make windows bootup sound when you turn it on ,can you hear fans running ,harddrive spinning .things like that

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