> this little TV set (14" by philips, more than 20 years old) started some
> months ago to hiss, it was mainly a little EHT leakage from the junction
> between the LOPT and the ultor cable. It was annoying but my parents
> didn't care at the time (I'm not a TV user). It had no other visible
> symptoms, so I think the line final transistor (little BU508) was
> holding well. Since some days, the EHT started to spark violently from
> the cable to ultor junction and the set was shutting down, so I couldn't
> ignore the problem anymore, my parents want to watch the TV!
> I opened the set, cleaned 20 years of dust, redo many solder joints that
> were just looking suspicious, put an heavy amount of epoxy in the
> leaking junction on the EHT transformer and some teflon band over the
> epoxy and did the same on the cable to suction cup junction.
> I also checked the +125V line (this is primary supply on the output
> transformer that then goes to the BU508 collector) and it was well in
> specs, however lowered to 124.6V which is still in specs and gives a
> little less EHT.
> Ok, all this effort cured the leakage over the transformer but after a
> good amount of epoxy, the juntion near the ultor cup was still sparking
> (this started again after one day from the first "cure"). I re-opened
> the set and put a good amount of hot glue over the epoxy and it's
> holding again now.
> It's normal for 25 kV to jump over some 4-5 mm of epoxy or I'd better
> check if the EHT is way over its normal value for this set? Yes, I have
> a 1000:1 probe but I never used it on a TV set, it's just for
> oscilloscope repairs (where voltages are much less than that). Also I
> can't really see any other malfunction on the set, so I wonder....
> Any expert out here? How do you measure the EHT on a TV set exactly (if
> this is something doable in the first place)?

> TIA

> Francesco IZ8DWF (who watches tv only from the back of the set and not
> very often)