My tv has developed a fault, which is really annoying me. Its about 5 years old and worked fine until now. The picture is fine one minute then all of a sudden it will get a yellow tint for about half a minute, then it will be normal again.
Sometimes if you look carefully, there is a slightly yellow column on the left of the screen, but its really not noticeable until the complete screen goes that colour.
Red + Green = Yellow when discussing light. So "picture minus blue" equals "yellowish picture". Which tells us that your blue electron gun (or supporting circuitry) is crapping out for some reason. Without much more detailed information, you're going to get nothing but guesses at the cure. If you're lucky, one of those guesses will be the right one, and will fix your problem. Only trouble: Figuring out which one of the guesses is right.
For my guess: A capacitor or transistor in the blue circuitry is in the process of dying. I'm not even going to try to be more specific than that.
Inspect the solder joints (with the set powered off) on the little PCB that contains the socket that attaches to the tube. If the solder joints appear to be cracked (which I've seen many many many like this), re-solder them (with the set unplugged of course), and see what happens.
I have computer monitor that does this, sometimes it powers up fine, other times it doesn't. Sometimes it fixes itself, however, if you hit the monitor, you can make it fail or repair the problem.
Try smacking the side of the TV during this problem to see if it changes when you've done this. The yellow line on the side of the screen? well, hmm, could be related, (blue drive not working properly), etc...
Now why wouldn't you smack it? If you can't reproduce an intermittent fault that is obviously due to a cold solder joint?!?!
This is called quick and reliable troubleshooting. In my line of work, if a technician did the 'logical' thing, he'd be repairing a unit for hours, and getting fired for his practice. In the field, when problems arise, you do what you can to get a problem to be duplicated, ie: smacking.
Offering a suggestion not to smack isn't good enough, sometimes viewing solder joints isn't good enough, sometimes traces crack right at the end of the joint/pad/trace, or, the component separates from its terminal (ie: electrolytic cap).
Without knowing your electronics background, I bet that you'd take too long to repair the simplest of jobs.
I've got years of experience as a TV technician, and you? I'm not trying to be an idiot, this is just a follow up to your vague attempt at replying to another posters answer that seems quite logical actually.
In Televisions, most common problems for such as the OP mentioned is due to thermal stresses on the components, especially how fragile the cheap sockets on some televisions are.
I visited your site, you have to also think, sometimes it is not the component that isn't mounted well (which does cause cracks to develop), however, wave soldering or blown on doesn't produce the best results all the time. Sometimes, due to oxidization, only a trace amount of solder on the skin 'outer joint', is making a connection. Over time, due to thermal stresses or mechanical stresses, the solder joints form cracks, either completely disconnecting the component in question, or increasing resisitance.
Most common fault of electronics today are cold solder joints, agreed? Your site shows a couple of examples.
Thanks to all who replied both on the newsgroup and through email. Didn't want to spend any longer on this tv so it ended up in the bin. The repair bill just to look at it and tell me what's wrong were too high, never mind actually repairing it. Thanks for your suggestions.