Hmm... that could be anything.
1. Check the cable connection between your monitor and the video card (make sure it's not loose).
2. Make sure the video card is not loose.
2. Try testing it using a different monitor.
Basically, if all connections are OK, and the screen still flashes when you use a different monitor, then it's the card. Otherwise, it's the monitor. What monitor do you have, btw?
1. Check the cable connection between your monitor and the video card (make sure it's not loose).
2. Make sure the video card is not loose.
2. Try testing it using a different monitor.
Basically, if all connections are OK, and the screen still flashes when you use a different monitor, then it's the card. Otherwise, it's the monitor. What monitor do you have, btw?