Here’s one reply I got from an electronics site:
By premtech
Rank: Guru
Rating: 88%, 377 votesThe procedure for correcting dark picture is EXTREMELY dangerous… If you’re not sure about what you’re doing call a qualified technician or you could seriously hurt yourself or get killed!
Picture Dark, abnormal, Changing Color Temperature
Clean the Spark Gaps on each CRT PWB. Remove the Cap, clean the contacts with thin fine sand paper, blow out, reseal.
Remove the CRT Sockets, clean the pins on the CRT. Push the CRT socket on and off several times.
Make really sure before you sttart this process that the Tv has been unplugged for several hours and that you discharge the crt as you remove the anode. There is some extremely high voltage present for hours after the Tv has been off…
Or get a reputable shop to come out and do the procedure for you - - might just save picking yourself up of the opposite wall.
Bill
Alright, potentially lethal doses of power! TV’s been unplugged for about 5 days now, I just worry bout those caps holding the juice in.
Does make sense though, if the gap’s not clean you’ll get lower lumen output.