Hi
My BG808S has a problem on the blue tube. There is a constant raster, no brightness modulation (no picture). Gain and cutoff do not make any difference , but adjusting G2 changes the intensity of the whole raster.
Anyone know what is bad. This pj has been flawless for years, needs only minor touchup.
I know the next troubleshooting step is to switch the input cable on the neck board between to crts, but I was wondering if anyone knew for sure if this is a neck board problem, or on one of the main boards.
Troubleshooting is a literal pain in the neck with a ceiling mounted projector, so I was thinking why not give a shout.

Thx
Larry

Chances are the CRT socket itself is bad (the video amp is mounted to the socket. I've got stock of spares.

Curt

Curt
Like I said, troubleshooting upside down is a pain in my neck. Is the only connector on the neck board the one on the top (bottom if upside down). 8 or 10 wires (from memory). If so, I will swap them and see if the symptoms follow the crt, or the input.
Thx
Larry

Hi again Curt

I swapped the cable on the neck boards and the problem stayed with the blue crt, I assume that proves it although upon removing the neck board, I see there is another small cable down to the motherboard. Do you know what signals are on that one, it is too short to swap between colors.

and 2 more questions

What is the price on a neck board for a BG808S

The long red wire connected between the neckboard and what appears to be the G2 unit. How do I detach it, wasnt obvious, and I didnt want to force things and break it.

Thanks in advance
Larr

Lower cable have filament voltages, G1 and G2. Chancing just cables won't tell much. Just if something is wrong before rgb amp, that is pretty rare with this kind problem.

Swap rgb amp with another color to see if it's rgb amp or tube. It's not needed to chance those rgb amp hv cables for swap, but those can be removed by pulling that rubber up with srew driver and pulling connector up using pointed pliers.

Neck cards goes around $50-100 I think.