42LC7D Backlights burnt

[HMRG123]

Have a problem with a 42LC7D that will flash one backlight three times during power on. I measured the resistance of all the caps next to each lamp and the one that turns on has 9.9k and 8.9k ohms on the two caps. From what I understand, these caps are leaking and need to be replaced, right?

Also, all other lamps glow except for one. The pcb was burnt below the lamp and it appears the lamp itself has a crack where it arced to the PCB.


I scraped the pcb underneath, and did not see anything. Are these lamps replicable? One cap for this lamp measures 2.8k ohms

Thanks in advance for any help.

[budm]

Re: 42LC7D Backlights burnt

I cannot see the pictures.

[HMRG123]

Re: 42LC7D Backlights burnt



Can you see this one?

[diif]

Re: 42LC7D Backlights burnt

Yes the tubes can be replaced.
It's ESR and capacitance you measure of capacitors. Not their resistance.

[HMRG123]

Re: 42LC7D Backlights burnt

Understood. I read in another thread that if the caps read resistance as a quick check, the lamp will be extremely bright; which is my case.

I have replaced the bulb from CCFL Warehouse but they did not have the 3.4mm x 940mm lamps. I ordered 3.0mm x 940mm. This circuit looks good, but several of the other caps burned up when I attempted to turn on the set. Is it typical that many of theses caps will go out at the same time? Should I just replace all of the caps?

[HMRG123]

Re: 42LC7D Backlights burnt

So I replaced all of the caps on both sides to the CCFLs and two of 18 lamps. When firing up, the power is arcing across the cap even though there is a gap in the board. This causes the associated lamp to glow bright and the others to be very dim. The arc is pink in color and burns the outer part of the cap and board. I can clean the parts, but the next time I fire up the tv, it arcs at another cap. Any Ideas?