Hello everyone,
I have a set of Benq FP731 monitors. Both of them had the classic problem of going dark after a second or two. Both have a Benq 48.L8202.A00 power board. I was able to fix one by replacing all the C5707s and a fuse. I did the same repair on the second one but it is giving me problems. The upper two (right side) transformers seem to be causing some sort of overload. But its not due to a transformer(s) itself.
This is the story so far: If I only plug in the lamp cable for the upper transformers (T753 and T751, to the RIGHT in the first image) the screen stays dark. If I plug the same lamps into the lower transformers the screen will light up for 2 seconds then go black. It will then light up again for 2 more seconds and then turn off and stay off. I unsoldered the transformers and swaped their locations. The problem does NOT follow the transformers. Something that runs the upper set of transformers is causing some sort of protection mode. I swaped the whole power supply all 4 lamps work fine. I also replaced ALL the large caps.
Items I have replaced are marked in the image. (caps have also been replaced) I also re-soidered all the known problem areas for this power board.
Benq 48.L8202.A00
Thanks.
I have a set of Benq FP731 monitors. Both of them had the classic problem of going dark after a second or two. Both have a Benq 48.L8202.A00 power board. I was able to fix one by replacing all the C5707s and a fuse. I did the same repair on the second one but it is giving me problems. The upper two (right side) transformers seem to be causing some sort of overload. But its not due to a transformer(s) itself.
This is the story so far: If I only plug in the lamp cable for the upper transformers (T753 and T751, to the RIGHT in the first image) the screen stays dark. If I plug the same lamps into the lower transformers the screen will light up for 2 seconds then go black. It will then light up again for 2 more seconds and then turn off and stay off. I unsoldered the transformers and swaped their locations. The problem does NOT follow the transformers. Something that runs the upper set of transformers is causing some sort of protection mode. I swaped the whole power supply all 4 lamps work fine. I also replaced ALL the large caps.
Items I have replaced are marked in the image. (caps have also been replaced) I also re-soidered all the known problem areas for this power board.
Benq 48.L8202.A00
Thanks.
Comment