Hey Alan
ah ha
thats the line output transformer and that thick cable coming out of the top of that cap is carrying the 20,000 or so Volts to the picture tube. its the other end of where I was initially expecting the problem to be.
Now you need to let that fully discgharge before playing with it give it a day at least.
Personally , coz of experience I get a well insulated handle screwdriver with a long shafted blade, Connect a crocodile clip lead to the screwdriver blade and the other end to a grounded chassis point on the TV. and then slide the blade point of the screwdriver under the ultor cap on the back of the tube. Thats the ~ 2inch diameter cap with the other end of that thick cable. You will probably hear a zap as it discharges.
It pays to leave it there a while as residual charge can linger. !!!!
Once the tube is discharged you can then clean and closely inspect that arrowed part in your pic. You can already see that there is a bit of blackening there caused by the arcing.
Chances are that the transformer will have to be replaced. BUT and this is a remote possibility BUT, haha you may be able to clean and scrape away the arcing trace (track) across the transformer "plastic" material.
That really depends on ...
1) how deep in the carbonising of the track has gone into the plastic
2) if the arcing is coming down from under theat rubber cap and down the black plastic
3 or if there is just a "blow hole" in the plastic down lower ie. virtually right at the tip of the arrow where the EHT voltage is escaping
do a really good clean around there, DONT scrap yet, take another close up sharp pic, then scrape clean and take pic again and let me see the results
cheers
Dave
