not your exact issue but yesterday I worked on a 9000 chassis with a mass of faults, after doing the caps, flyback and usual brightness circuit faults I had the chassis running but with a strange width fault and a strange brightness issue- the width was too small but had adjustment, when you adjusted the width in the brightness would change and red cut off would increase. Not exactly your issue but similar
the brightness issue was down to c43(other known component failures are r90, r92,r93,r80 and c47)
the width issue was failing c36( other known component failures are tr16,tr17,c42,c41,c40,d12,d13), someone had also adjusted the h.lin coil at some point