Hi, still trying to resurrect this set, bought a backlight tester and all the backlights work when tested individually so i am back in the same boat, its becoming an obsession now with a determination that i wont be beaten, trying to find a suitable bulb to test the board "live" but i cannot make my mind up as to a suitable one, any help appreciated.
Use the neon bulb on each output to see if it is working.
A backlight tester isn't necessarily going to help - the TV may determine a failed bulb differently to your tester.
Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.
tested aech output with a bulb and when i connect the bulb to pl700 and pl701 in turn the set stays on, when its connected to pl702 and pl703 it goes 2 secs to black, now i am getting excited lol.
pl700 and pl701 are fed by the same transformer which was replaced because the original one was o/c, heres hoping that tom66 might get a chanc to jump back onto this thread.
Just gonna bump this to try catch tom66, hoping that its not a backlight problem but something on the protection circuit side, because when either of the backlights is replaced with a bulb the set does not trip.Could the new transformer be bad?? and not be able to drive the old backlights??
Yes, the new transformer could be bad. One way to eliminate a specifically located protection fault would be to swap the two transformers. If the fault moves, the transformer is probably bad.
Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.
sometimes when you look at something it can be staring you in the face and you cannot see, the set is working after i took a step back and started retracing what i had done with help from tom66.
original fault 2 secs to black
opened back cap missing on decoder board replaced still no go
general resolder job and cap testing still no go
then tom pushed me in the right direction with the check windings of transformer found one open circuit, replaced but still no go.
decided to do a general component check around the safety circuit and tom said try swapping around the new transformer i did and the fault followed the new tranny, easy new tranny faulty WRONG
Hooked up scope component tester and started comparing one agains the other and it was the older tranny which was faulty, all i can think is that when the first one went open circuit the other was probably going the same way but was weak instead which then put a mismatch load on the feedback circuit and caused the set to trip out.
Last edited by Sparks88; 03-11-2014, 10:07 PM.
Reason: spelling
Comment