Computer starts but, monitor keeps saying 'No signal' even though it is connected to pc.

Hello. I am new to Tech Spot. I have this problem for more than a week, and couldn't fix it. There are no computer technicians nearby, So I must carry the computer about 10km to get it fixed.

System unit and monitor is plugged into an extension cord. I usually connect the plugs to sockets while the extension cord is supplied electricity. So, about a week ago, I accidently connected the 'Earth pin' of computer's plug into 'Neutral hole' in the socket. (I don't know about electricals, so I am not sure if I used the correct words.) Then, I got a small electric shock and a spark came out of the socket. I immediately removed the plug and reconnected it correctly, but now the system unit turns on normally, but the monitor keeps telling, "No signal".

I checked the power cord and bought new two power cords for both monitor and system unit, also a new VGA cable. I connected them, but the problem still not solved.

I just registered here to get a help from this community, and I hope anyone will help me. Ask me for any information that is not clear and Thanks in advance.
 
110v or 220v?

Do you have access to "known good" components (2nd video card, 2nd monitor, etc) to allow you to swap out "unknown if good" components and/or a second system to test monitor to confirm it works properly?

Troubleshooting is all about narrowing the possible problems by proving components are good.

Spark from static or from mis-connection could impact video sub-system or power system, Video system is video card, signal cable, power cord and monitor. It sounds like you have tested the cables, so next thing is video card or monitor.

Might help if you could provide make and model for the system, the motherboard, the video card, the operating system.
 
110v or 220v?

Do you have access to "known good" components (2nd video card, 2nd monitor, etc) to allow you to swap out "unknown if good" components ......

Thank you for your fast reply.

Domestic voltage is approximately 230V.
I did not install a new (seperate) video card, so I have only integrated graphics card. I don't know about hardware well. I don't have an extra monitor or another computer, so I don't know which one has the problem.

The monitor: What are the signs for a broken monitor? It shows the 'No signal!' message.

I connected the system unit power cord incorrectly, can that affect the monitor?

If it have affected the video card, how can I repair it?

Also, here are the details of my computer.

System : Samsung DB-P55 (Many information is in Korean language, I cannot understand them.)
Video Card : Intel Graphics
Operating system : Windows 10
RAM : 1GB

Thank you very much.
 
System is 8 years old - 'end of life'. From what you tell me, it seems most likely that the motherboard based Intel GPU may be damaged. There is no manual available, so components cannot be determined. I would still like to test the monitor, but it is more likely than not that it is good.

What I would do if it were mine would be to try as 'last ditch effort' to enter BIOS, then load default settings and adjust them to match the configuration of the system. Alternative is a BIOS reset by removing battery, draining the energy from the BIOS SRAM. This should result in a reset of the on-board graphics unit. Beyond that, you might find a working used video card which fits one of the expansion slots and can be recognized as the system graphics unit.

All of these are complicated by the nature of on-board graphics as it may not be possible to navigate BIOS without a working onboard graphics unit to see the settings.

I would still like to test the monitor, but it is more likely than not that it is good.

Considering age and uncertainty of repair, you may wish to shop for a suitable replacement. I have acquired solid working Dell units coming off lease for as little as USD75. (Optiplex, 3rd gen i5, onboard graphics, 4GB RAM, Win7).
 
From what you tell me, it seems most likely that the motherboard based Intel GPU may be damaged.
The GPU is integrated into the Northbridge chipset, so if the GPU was kaput then the whole system wouldn't start. I suspect it will be a component or two on the motherboard itself that have gone pop, and it's affecting the VGA output.

I have acquired solid working Dell units coming off lease for as little as USD75. (Optiplex, 3rd gen i5, onboard graphics, 4GB RAM, Win7).
I've done the same for work - you can pick up some fantastic office-based machines for very little money, these days.
 
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