Hi folks,
Had this one kicking around for a while - Came in as backlight cut after various intervals, sometimes staying on all day, sometimes off after a few minutes. Changed all the P/S caps, noting after that the 24v supply didn't cut.
Same problem - Replaced the 4 inverters from the Flea - same problem. Seems in this set the main doesn't control the inverters, and when set is turned on, so are the inverters.
Curious about a couple of things - Haven't yet had the screen apart, as it's bit of a beast. Wonder if the tubes only go half way across the screen, and could tubes be the cause of the problem ?
Generally with tube problems, the inverter cuts after a few seconds - would try a tube check on all possible 48 tubes, but not too sure how to do it, not knowing whether tubes are straight or 24 U shaped, and where they are grounded.
One for the knowing - Thanks - Chris.
Inverters are LG/Phil 6632L-0159C Master, and three slaves.
Later - Took the screen apart and found 24 rather long tubes which seem to be driven each end by the 4 inverters - two trannies per tube. Checked with my cheapy tester and half lit up in a dim sort of way - The others didn't, and there was no end corrosion often seen with smaller stuff. Note that 40 inch set tubes are just an inch or so shorter, so will try a few for fun, as have plenty from screen smashes - probably won't notice the difference.
Replaced the eight duff tubes with 'heat shrink' to cover the shorter bare ends from possible flash-over - Re-assembled to discover a small fly that always sat on some one's nose squashed centrally between the diffuser sheets and the LCD panel - Always the way in summer. Removed the fly after an hour or so.
Set now works - Small dark side patches visible that most folks wouldn't notice. Inverters now don't cut out.
Had problems with the set's dvb as tuning seemed to drift a bit, but a box does the biz.
Glad it's only for fun, as set weighs 33Kg without stand, and tend to stagger a bit shifting it - anyone with a stand ?
