if you've tried another monitor & have the same prob. then U could have a bad adaptor, if prob. is gone w/a different monitor then the monitor is the prob.(internal damage) there's no cheap way out, (probably a bad yoke or final), take it to a TV shop & get their view. of course, maybe they'll add it to their junk pile which is probably just as well. could also be defective VGA cable.

answer yo you problem... try to resolder the crt socket there must be a loose contact with some solder