[Taken directly from Cadillacman's monitor sticky in this very forum]
Common k7000 issues - common repairs
FLYBACK ISSUES:These monitors have a high flyback failure rate. Theres 2 o.e. flybacks used on these monitors apparently. Both interchange, but i have seen a difference. The older monitors run a flyback with white adjustment knobs. This flyback sucks. The plastic casing will literally fall apart in your hand and they tend to crack alot. If you come across one, REPLACE IT NOW whether the monitor works or not! The other fly is all black. If you see a yellow goo bubbling out of the seams, its bad/going bad. Look it over very well. Find a crack? REPLACE IT! Replacing a cracked fly on a working monitor will save you alot of money in the long run. Black ones also crack but not as often. Some of the replacement flys have been failing too, make sure to double check if you have issues after a repair.