[Red to black]

I know which chassis it is, if you have not adjusted the A1 screen pot then leave it be, don't make it any worse than it it is, maybe you have set the width incorrectly but either way it is the X-ray protect line that has activated and giving error code 8.

I may be able to give/send you some technical info. on this chassis, but be warned the way it does EW correction is far from conventional, it uses two line output transistors for a start, it varies the EW by altering the phase of the drive to one of them against the fixed phase of the other it thus alters the width dynamically on a line by line basis using pulse width techniques, these complicated sets are very tricky to work on!