Hi all,
I have a 21" Sanyo TV set (Philips tube) which, when switched on, starts up very briefly and arcs once between the anodes visible in the long uncovered tube neck. The line stage shuts down so quickly that it appears not to start-up at all, but clearly it is doing in order to provide the voltages required for the single arcing. The set then just stays in standby mode with the front LED blinking 3 times in a row repeatedly.
I cannot find blink codes for the front LED, but I can assume it's in a protection mode (unless anyone knows differently?) and need to find the reason for the arcing. Initially I had found that R666 - bad omen or what - (8R2 5W) lifted out from its intact solder joints. Fibreglass-pen treatment to the legs of the resistor and resoldering put that right, but did not affect this fault. The resistor is a surge-limiter in the feed to the line-output transistor (or HOT, if you prefer that terminology). Maybe this is coincidental or a clue as to what may have happened to cause this arcing.
The line-output transistor and its internal diode is fine and so is the snubber capacitor, so they're ruled out as causing excessive-voltage from the flyback. I'm not sure what to do next... LOP transformer or tube defective? I know Philips have been having tube problems for a while now, already written off a 32" one with internal leakage causing a protection fault.
Thanks all, James
PDF service manual for this set/chassis available to download here: