step 1: determine what monitor you have...
step 2: is there anything wrong with it?
I currently am working on a vector system, but currently do not do any monitor repairs, i send them all to jim, i only would trust him on monitor repair next to me.. ( but i generally take him like 5+ of the same monitor )
As for "Bulletprofing" there isn't much to a vector monitor to Bullet Proof.. besides cap kits and making sure the deflection drive transisters are well insulated and have good thermal compound on them.. some people like doing LV upgrades on the 6100 and some do not..