I have a viewsonic q19wb and every 15-30 min it goes black for 3-5 seconds. My video drivers are up to date. What is the problem?

It could be that one of the capacitors inside are on their way out, you will find if this is the case that it will start happening more frequently and sooner after you have switched the monitor on, is it still under warranty?

fortunately yes, it is still under warranty. I'll send it back and see if that fixes my problems. Thanks.

No problem, if for what ever reason they refuse to fix it, if it is one of the capacitors they are really easy to change.