Wikipedia:Reference desk/Archives/Computing/2020 January 22

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January 22

PC Video Fault

The PC gives a low-contrast, streaky display on a VGA monitor.

Which component is likely causing the faulty display shown on a monitor connected to the VGA output? How would a serviceman test this?

Pictures of video board, etc.

Edge of video card showing VGA output socket The PC gives a low-contrast, streaky display on a VGA monitor. Video board component side. Click to enlarge. Video board underside. Click to enlarge. Notes: The VGA monitor and VGA cable have been tested ok. The PC digital functions are ok. The specs of the PC are HP Pavilion 9910 desktop 1.4 GHz, 128 MB, 40 GB disk, 32 MB display memory, nVidia GeForce 2 GTS. Windows ME.

DroneB (talk) 16:00, 22 January 2020 (UTC)

That card is from 2000 or so, so it is getting on in years. The image of the cooler shows a lot of junk in it, so it might have insufficient cooling.Try cleaning that and see if it helps.

Otherwise, the driver may have gone bad, you could try reinstalling it (if you can find a source for it).

I've found the manual on https://ideafix.name/old/video/BREND/asus/agp/v7700/v7700-101.pdf but it does not list your problem.

If the chip itself is damaged due to age or temperature, fixing it is nearly impossible, but you can still find the card being sold on amazon and e-bay. Rmvandijk (talk) —Preceding undated comment added 07:24, 23 January 2020 (UTC)

This issue looks like an unmatched or unterminated video signal, or just a reflection on damaged VGA cable. First replace the VGA cable. Often less shielding and less maerial on the shielding is used. Chip damages are unlikey, if full operation like this picture is generated, the VGA card also uses drivers or protecive devices on the output, see components close to the VGA connector. If the issue is not caused the cable, let's focus on operating voltages, but the electrolytic capacitors do not look blown. On this frequencies, the tantal and ceramic capacitors needs to be in good condition. I can't see the condition of those in monitor. Hope the VGA cable is plugable on the monitor, some are not. --Hans Haase (有问题吗)

I agree that the VGA connection would be suspect here. Check for poor connection along the pins and holes in each side of the connection. You could also double-check by using the Composite or S-Video outputs to see how they look; hopefully you have something that can accept those formats. How did you test the cable and monitor? Did you swap them out for another duplicate? Elizium23 (talk) 04:18, 28 January 2020 (UTC)

If you can, generate a smith chart of each wire of the VGA cable, but just replace, often it is a problem of the shielding wire. Also turn the power cord by 180°, if possible, British, French and American wall plugs with protective earth can not, but German ones can, wich often causeing the 50 HZ sound and same picture issue, but more soft and not depending in a displayed window. --Hans Haase (有问题吗)

Update: make shure, You use the monitor in its specified range, not blowing al line transistor. Even old tube televison sets had this problem when used nininterlaced like computers did. In case of doupt, reduce screen resolution or frequency. --Hans Haase (有问题吗) 12:15, 28 January 2020 (UTC)