I would definitely try a different monitor with your computer, just to completely eliminate the chance that it's a computer configuration error.
With that said, I'm almost certain this is an internal problem with the monitor. It could be capacitors, it could be something else completely. If the monitor is under warranty go that route.
If it's unusable and not under warranty many local computer shops can try to repair those types of problems, or you can buy parts online and try to repair it yourself. I'm no electrical engineer but I've had about a 50% success rate of replacing capacitors and having the monitor work again. It's a cheap, and fun, method if you have the time and tools.