Are we talking CRT here or some of that wierd and witchcrafty TFT things?
I'm assuming CRT, in which case in my experience any display flicker or on/off sound clicking noises is usually the precursor to hardware failure... Ive had a few 'old' bits of kit do some similar things- especially the 'clicking' sound. They have always died relatively soon after, but that's not to say you should expect the monitor to fail completely the next time you turn the thing on. One of my oldest ever monitors has just recently died, having been a trooper for about 5 years as the original primary monitor and then as my extra desktop realestate for the last two. Eventually the colour went then it just refused to turn on any more... I guess it was just too tired to carry on
