2 I suddenly have the black screen of death!
I have removed the back panel and want to test the Power Supply "high voltage" going to the backlight module via the 2 wire (blue and white) connector. I am not getting any reading on the 2 wire connector with the TV turned on (sound and faint picture are present). I have tested for the 720VAC with both the Main Board connected and disconnected. No voltage. I have checked the fuse on the PowerSupply. If the BackLight module has failed, will this damage the PowerSupply? I am concerned that if I just replace the PS, will it fail again?
Dave
Is this a good question?
Score
1
@davealex we have to see your boards and the wires/connectors you are referring to. Adding images to an existing question
by oldturkey03
@oldturkey03
This may be an interesting one.
There's a backlight repair "kit" for the model so perhaps it's a known problem and also looking at a zoomed in (click twice to really enlarge) image of the power board the inverter voltage on CN1801 is 720V AC!! (see value in output rating box on the board near the 46" marking, top left), so perhaps it may be a CCFL LCD TV and not a LED TV. It's about the correct vintage
Cheers
by jayeff
Thank you for the quick responses. I have uploaded my question now that I have tested the PS output and confirmed there is no 720VAC. I have tested this with the TV turned on and the Main Board also disconnected. So...is there a way to test the Backlight module and lighting? From reading other comments on your site, it would seem that it is a Backlight failure that causes the PS to also fail? Dave
by Dave Alex
@jayeff definitely a CCFL based on the power supply. @davealex You can't measure that voltage with a regular multimeter due to the frequency of the transformers. I'd go with the repair kit and see if that fixes it. In the meantime, let me check the schematic for this board. Check that fuse by the diode bottom left of the transformer looks like "58025", see what voltages you get on that (continuity as well)
by oldturkey03