Hi there, and welcome to JustAnswer
Just to test, can you make sure the monitor cable is connected to the new graphics card.
If it is, connect it to the other video plug (onboard graphcs card) and tell me what happens as well as the make and model of the computer please
ok, can you take out the graphics card please.
Start the computer and keep pressing F8 until a menu appears, choose SAFE Mode and then shut it down
Then put the card back in and start the computer in Safe Mode with Networking and let Windows reinstall it please (keep the monitor cable connected to the other video port)
Restart the computer and test please and let me know if the problem persists
ok, thanks for the information
If nothing is happening when you start the computer (no fan running, no lights) then it looks to be a problem with the Power supply unit on the computer.
If you do hear the fan running, then I would take out one of the RAM modules and test. Do the same for all RAM modules.
If after doing this you still have the problem, then there is a faulty component on the motherboard. You can have a warranty done on it, but if no warranty exists, I would be very cautious having it repaired as this can cost more then a new motherboard.
If you require any additional information, please do not hesitate to ask me.
Regarding the power supply, I feel it s not able to produce enough power for the video card that you have put in. It works, but from the symptons you are describing, it seems that the graphics card does not have the power to display the screen image.
It should work though and this is why I feel it is a problem with the power supply on the computer.
I do recomend that you have the computer checked for problems under its warranty, as you should not be experiencing these problems.
I would do this before having you check the RAM yourself, as the factory will do this when inspecting the computer.
If you require any additional information, please do not hesitate to contact me.
From here it is very hard to tell. Regarding costs this will depend on your location
My advice would be to have a computer shop do a diagnositcs. They can then track down the faulty component and can advise you on the cost to replace it.
I do however, based on the symptons suspect the power supply, but a physical diagnostics on the computer needs to be performed to verify this.