Hi guys, I have a Dell 2407wfp with a backlight problem. I disassembled it and took a couple of photographs with the backlights powered on.
As you can see the u-bend CCFLs are not full lit to the end. They also flicker a lot too. It's as though they don't have enough power to be lit at full brightness to the ends.
I don't have an ESR meter or Ring tester - only a multimeter. I did the hairdryer test and heated up the capacitors on the inverter board which did have a slight effect on the bulb brightness at the ends. There was no effect when doing the same to the power board.
I switched around the bulbs onto different inverters but there was no change. When I unplugged 3 of the bulbs the other 3 lit up perfectly brightly (but obviously only for 2 seconds due to the feedback loop). This happened with any combination of 3 bulbs and inverters. Adding more bulbs back made the problem progressively worse. There were no obvious signs of damaged components on any of the boards.
What do you think the problem is? Should I try replacing the capacitors on the inverter board? Could it be a power board issue?
Many thanks for any help,
Leo
As you can see the u-bend CCFLs are not full lit to the end. They also flicker a lot too. It's as though they don't have enough power to be lit at full brightness to the ends.
I don't have an ESR meter or Ring tester - only a multimeter. I did the hairdryer test and heated up the capacitors on the inverter board which did have a slight effect on the bulb brightness at the ends. There was no effect when doing the same to the power board.
I switched around the bulbs onto different inverters but there was no change. When I unplugged 3 of the bulbs the other 3 lit up perfectly brightly (but obviously only for 2 seconds due to the feedback loop). This happened with any combination of 3 bulbs and inverters. Adding more bulbs back made the problem progressively worse. There were no obvious signs of damaged components on any of the boards.
What do you think the problem is? Should I try replacing the capacitors on the inverter board? Could it be a power board issue?
Many thanks for any help,
Leo
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