Macmadant said:
I think it's out of warrenty now, so buying a new one would be my only option, will it eventually not display any image on the screen or just flciker and tick all the time ?
Based on my limited experience, it will keep flickering for a while (could be a day, could be a year), then at some point you'll hear a nice pop and that will be the end of it. As explained, it's probably shorting somewhere internally, and eventually it will burn out wherever the short is, and it'll almost certainly cost more to get it fixed than a cheap LCD (or, heck, an even cheaper CRT on closeout). Even a 15" LCD probably has about the same useable area as your 17" CRT, and it'll be much easier on the eyes.
5 years isn't bad for a no-name CRT, though I've seen Sonys last almost a decade and some Apple monitors last at least that long.
[edit:]
Just for reference, you can, for example, get a refurb (30 day warranty) 19" recognizeable brand CRT from
MegaMacs for about $80... except the shipping is going to run you almost $50.
A much better bet would be to poke around NewEgg; you can get a passable, new
ViewSonic (one of my favorite brands) 17" LCD for under $150 with about $10 shipping (it even has speakers), and there are several Acer LCDs in the same price range. Or, if you're really on a tight budget, they have a few 15" no-names with mail-in rebates for about $120 shipped.