I got the this pny geforce 8400 gs pci card but it sends nosignal

Yes, but check your BIOS and make sure the PCI-E slot is enabled.

Also, when you say doesn't start, you mean just the screen? Right?

There could be any number of problems causing a Reboot loop. But the obvious one is that your graphics card won't work with Windows 7. It is too old.

Find the Driver for it online, NVIDIA's site has all the drivers you need.

you must have the correct driver installed go to www.gigabyte.com and run the dianosis program and download the correct driver

have you tried a different graphics driver? the NVidia 8400 did have failure problems but yours might be ok.

see that ur vga cable is inserted on a graphic card
and reset ur cmos

hi throw your cpu in the bin and you parents will get you one

Hello gabini248,
Disabling "restart on system failure" may fix the problem: Right-click on My Computer, click Properties, click the Advanced tab. Under “Startup & Recovery,” click Settings. Under “System Failure,” uncheck the box at “Automatically restart.” You may have to restart your PC for the effects to take place.

overheat, you might have damaged it while installing.. etc

I have the same system and card. The problem is the system is trying to run two monitors at once. Use Windows safe mode (F8 during boot) to uninstall any Pny drivers you may have put on. Reboot. Install the pny drivers again. Before rebooting, use the device manager to look at the display drivers. There should be two, an Intel one, and the pny Nvidia one. Disable the intel driver and reboot. Worked for me. Youmay also want to upgrade the power supply. The 3000 has a 225W and the 8400 card wants at least 300W.