You might have a video IC problem. I have a 1270 in for repair. This problem you describe sounds like exactly like what is happening to this unit, except the one I am servicing has the problem on blue.... I am waiting on parts from Curt to repair it.
To check the board out:
Open the hood and lift the two top boards. Remove the piece of aluminum from the rear of the projector - there is a fan on each end(side) of the alluminum - it forms a sort of heat sink tunnel that air flows through. Just remove the top plate of alluminum. This will show you the 2 video boards. The board on the left does the red and green. The board on the right does blue.
SWAP the black coax video feeds going to the Red and green sections. If the problem remains with the red tube then put the coax leads back. If the problem did not move with the coax the the problem is being caused by either a bad CRT or a bad video driver board. If the problem did move with the coax, you will likely need professional assistance and/or a schematic to go further.
Next, swap the wires going to the neck boards. (I made up a small adapter cable to do this. You could also swap neck boards, but that is a bit more involved.) I suspect the problem will move when you swap neck board wires on the red/green board. Expect the green to show the problem with the wires reversed. If so - you have now confirmed the problem to be in the video board. If not, it may be "tube tyme."
If the problem is in the video board, the odds are the video amp is bad. If you are capable with soldering, swap the VPH-05 ICs around and see if the problem again moves. If so, replace the IC. Cost from Sony- aprox $125+
If you are not comfortable soldering the IC, maybe a forum member has the board for sale? If not, perhaps someone can recommend a source to you...
In any case- make sure to clean the fans and opening to the video boards. You will likely find the holes in the screen plugged up, resulting in the VPH chip overheating and its subsequent failure. Some also suggest some heatsink compound between the VPH heat sinks and the top alluminum plate. This is probably a great idea to help keep things cool...
Best of luck. Hope this helps.
--Kieth
To check the board out:
Open the hood and lift the two top boards. Remove the piece of aluminum from the rear of the projector - there is a fan on each end(side) of the alluminum - it forms a sort of heat sink tunnel that air flows through. Just remove the top plate of alluminum. This will show you the 2 video boards. The board on the left does the red and green. The board on the right does blue.
SWAP the black coax video feeds going to the Red and green sections. If the problem remains with the red tube then put the coax leads back. If the problem did not move with the coax the the problem is being caused by either a bad CRT or a bad video driver board. If the problem did move with the coax, you will likely need professional assistance and/or a schematic to go further.
Next, swap the wires going to the neck boards. (I made up a small adapter cable to do this. You could also swap neck boards, but that is a bit more involved.) I suspect the problem will move when you swap neck board wires on the red/green board. Expect the green to show the problem with the wires reversed. If so - you have now confirmed the problem to be in the video board. If not, it may be "tube tyme."
If the problem is in the video board, the odds are the video amp is bad. If you are capable with soldering, swap the VPH-05 ICs around and see if the problem again moves. If so, replace the IC. Cost from Sony- aprox $125+
If you are not comfortable soldering the IC, maybe a forum member has the board for sale? If not, perhaps someone can recommend a source to you...
In any case- make sure to clean the fans and opening to the video boards. You will likely find the holes in the screen plugged up, resulting in the VPH chip overheating and its subsequent failure. Some also suggest some heatsink compound between the VPH heat sinks and the top alluminum plate. This is probably a great idea to help keep things cool...
Best of luck. Hope this helps.
--Kieth
