|
Can you measure the voltages at the heater, grids, cathodes, and screen grids (if you have a meter that can measure that high). Those may give us some insight into the problem. Also if you have an HV probe please measure and report the HV, focus, and convergence voltages.
Also in opperation there is no purple or blue glow in the neck of the CRT correct? If the CRT is going gassy and there is enough gas for abnormal conduction between elements in the neck, but not enough to extinguish the beam or cause neck to HV arc then that could possibly cause symptoms like this as well.
These readings should tell us what is causing the brightness to be lower than what it used to be.
For loss of video see my post in the other thread on this set that you and I replied to.
|