Video/Monitor problems

[IFMU]

I think this is about the best place for this so here it goes :D

Ok heres the deal.. I was given an monitor a few weeks back. It has a problem that I think I know what it is, but not totally positive. It seems to run fine for some time, but then a black line begins crossing the screen.. it runs up and down, it also gets wider in the middle () kinda shaped like that.. I messed with it some and found that the back cable seemed kinda of loose. I opened it up and it looked like the bottom board on the inside was loose and was causing it to do that.. I got it to be a little steadier in there and put it back together and it seemed fine for a little while, but began doing it again. Any ideas as to what may be causing this? or any fixes?

[Breadfan]

Hmmmm...are you sure its the wire in the back? Even if it was "loose", it should be working fine as long as all the connectors are still soldered to the board good. It is possible there's a short in the cable...try shaking the cable or bending it while the monitor is on...if the black line you see changes at all as a result of you're jostling the cable, than it could be short in the signal cable.

Otherwise, there are a few other things to consider. If it works fine for a while but then starts up and gets worse, than that might be indication of a component that is failing due to heat. Perhaps the power transformer is getting hot, (don't go grabbin' it to find out!), or other power regulators. If it seems like things may be getting kinda warm back there, take the cover off and direct a fan over some of the components and see if that helps at all.

BE CAREFUL THOUGH. Don't grab things back there...the capacitors have enough power stored in them even after a few days to send you across the room!

Another idea is to check you're flyback transformer. This will be a sorta square looking box (they vary) that may have two knobs on it. The best way to find it is to look at the picture tube. THere will be a wire coming off of it with sort of a "suction cup" on the end. Follow that wire and it'll take you to the flyback. While its running, lightly tap it with the insulated end of a screwdriver. If you're screen's problem gets worse, you're flyback may be shorting. The main symptom of flyback shorts though, are screen flickers.

The next option is to try turning some knobs. On the bakc of the picture tube where the cathod gun is, there may be some knobs with ends that fit phillips screwdrivers. (obviosuly, location, size, and number of these knobs varies). They may be labeled as well. They control things such as the focus of the beam, and the amount of power. If you can find the power one, try giving it more power, it'll up the brightness. However, since you'r screen is not dim to start with, this is most likely not you're problem...but its worth a shot. Just make sure you remmeber where things are set before changing them.

You can try the knobs on the flyback too, but I don't quite remember what they do...

There's a few things to try out...but its sounding like the cathode gun may be fualty. My guess is that this is heat related, so I'd look for overheating problems first.

Mike