Ok. So. I've got a 13" 20 EZ out of my
cocktail. I've gone through with the help of some other forum members on here the troubleshooting guide and flow chart for this monitor. I just want to narrow down with a new thread what has been done. Yes, this is the one I have been working on for a while.
Items replaced:- cap kit
- flyback
- HOT
- B+ Pot
- B+ filter cap
- IC601 voltage regulator (x2 -new one and one off another board has been tried.)
- Q901 transistor (x2 -new one and one off another board has been tried.)
- IC401
The area of the board that has most of this stuff has been reflowed. Diodes D601-604 check out, but I could still replace them all from the ones off of another board. H-Hold pot has been checked and tests ok.
Symptoms:- No picture
- You can hear the flyback come on
- you can feel static near the tube
- There is a "pop" when the tube is discharged
- TP91 reads 130+ volts
- AC at the transformer reads 108v
- adjusting B+ pot does nothing
- adjust H-Hold does nothing to the B+ value
- Pin 9 of IC401 reads 0.6v
Based on the troubleshooting guide it says to check the power reg., hold-down, and high voltage circuits.
Questions:
Have I addressed all of the things in the trouble shooting guide? What are the hold down and high voltage circuits?
What else should I check?
