[timmy]

Originally Posted by Username1

Unless you can get others to agree, I think it's unlikely any arcing made the glass blue.
Unless it's some contamination. Does it scrape off....? If it's "in" the glass, then it was
there from day 1, I can't see arcing doing anything to glass....

You should be able to measure cathode current on the tube, it's the low voltage end of
the tube, and you should be able to measure each gun, I think current is listed on
the schematics.....? If there is HV issues, just turn the brightness up and down, and
check the HV, does it fluctuate more than 3-5KV ?? Is it near where it should be 20KV ?

the hv has never been where it should be bright up certain scenes will lower to 19kv.reg circuit seems to be working but hv is not high enough to go into regulation to begin with.