Hi peeps.
I've got a LCD screen with a faulty backlight inverter board; everytime I try and power up the monitor the backlight comes on briefly, the PSU short-circuit protection kicks in and the whole lot turns off. This on/off cycle will carry on until you disconnect the power.
So I un-plugged the inverter board and the TV powered up fine. Plug the inverter back in and it shorts again. Now if I keep the inverter board plugged in and remove all 6 cathode connections the TV powers up fine.... then if I plug back in the tubes the TV stays on, but without the backlight.
Anyway I removed the power, plugged in 1 out of 6 of the cathode tube connections and turned it back on and the PSU, as above, cycles on/off protecting itself from a short. But when I put my digital multi-meter, on a volt range, across the small blue 18pF caps near the transformers the output from that tranny comes on and the shorting stops, TV on! I know this cause my digital meter goes crazy with high frequency AC readings. No back light though cause only one side of one tube is connected to the inverter; three tubes, 6 connections, 6 transformers and 6 caps.
So can this mean the 18pF caps are bad? I then tried this on all 6 outputs, and the same happens.
I've got a LCD screen with a faulty backlight inverter board; everytime I try and power up the monitor the backlight comes on briefly, the PSU short-circuit protection kicks in and the whole lot turns off. This on/off cycle will carry on until you disconnect the power.
So I un-plugged the inverter board and the TV powered up fine. Plug the inverter back in and it shorts again. Now if I keep the inverter board plugged in and remove all 6 cathode connections the TV powers up fine.... then if I plug back in the tubes the TV stays on, but without the backlight.
Anyway I removed the power, plugged in 1 out of 6 of the cathode tube connections and turned it back on and the PSU, as above, cycles on/off protecting itself from a short. But when I put my digital multi-meter, on a volt range, across the small blue 18pF caps near the transformers the output from that tranny comes on and the shorting stops, TV on! I know this cause my digital meter goes crazy with high frequency AC readings. No back light though cause only one side of one tube is connected to the inverter; three tubes, 6 connections, 6 transformers and 6 caps.
So can this mean the 18pF caps are bad? I then tried this on all 6 outputs, and the same happens.
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