A friend has asked me to look at a rear projection set that one of their friends picked up. They were told it was working, but I wouldn't describe this as working. I have no experience with rear projection sets, so I am not sure if I am getting in over my head. I will be paid for for parts, but this will be done as a favour.

http://65c02.org/images/ak/constv1.jpg

This is the onscreen image. It's fuzzy, underscanned, and CRTs are obviously far out of alignment.

http://65c02.org/images/ak/constv2.jpg

Removing the back I can see the position adjustments on the sides of the CRTs, but I can't work out how to adjust them as back/mirror has to be removed to get at them. Looking directly into the CRTs the images are sharper, but underscanned and bowed in at the sides. There is also a black strip across the red CRT that isn't on the other CRTs. Is this supposed to be there?

Where should I go looking for the bowed in sides and underscanning problem? So far I've found a couple of test points and the voltages are spot on. Should I back out while the getting is good?

There's an even older Toshiba front projection set kicking around as well, but I haven't even looked at that yet. I've got enough problems finding room for conventional sets let alone projection sets.

It has a problem with the convergence circuit. This is a very common with projection TVs. If it uses a pair of STK ICs they are probably bad. There may also be some open fuses, or resistors feeding power to the convergence board. Don't adjust anything until you've fixed the convergence ciruit.

I've managed to track down a partial service manual online that includes only the schematics. So I know now I need to focus on board C1, the business end of which is a pair of STK4872. The bad news (for them) is that the only source I can find for these so far wants ~AU$120 each plus delivery... Ouch :(

Has anyone dealt with any of the various online manual sellers that google keeps throwing at me?.

The full service manual includes the CRT setup procedure which will probably be essential if I can fix the convergence board. I don't mind paying for a download as long I am getting a good quality scan of the complete manual, not the partial file I already have.