No Backlight 40" Curtis LCD TV LCD4015AB

[XtraTN]

Curtis 40" LCD TV. I turn it on and the bottom right corner of the screen would light up very briefly for a second (not that bright). Seems the backlights are not turning on correctly. I can faintly see the picture on the dark screen.

Initial observations:

I opened it up seen no bad or bulging capacitors.

Checked the board that connects to the lamps and doesnt seem to be any burn marks on each of those blue ceramic capacitors.

Opened up to the ccfl lamps. Decided to resolder each joint connecting the lamps since each they looked a little burnt or cracked (might of just been the flux though). Turned on the TV and no change.

I checked around the high voltage transformers that feed the lamps.
and I found what seems to be a burned out ceramic capacitor (color faded compared to the one near it.)

Can't make out the label but I'm sure the two capacitors near the transformer are the same. Checked the other capacitor is labeled (from what I can make out):

.1V
SL6KV
47J

I decided to test it out by switching the two capacitors.
Tried turning on the TV again and this time only the TOP right of the screen briefly lights up for a second. So I think this ceramic capacitor is the problem.

Usually can these little ceramic capacitors cause the backlight to shut off?
Where can I find a replacement for this?

[budm]

Re: No Backlight 40" Curtis LCD TV LCD4015AB

They are ballast capacitors that do burnt out due to high voltage breakdown.
it is 47pf 5% 6000V rating, I would replace all of them at the same time, but make sure they are all the same value.
http://www.mouser.com/ProductDetail/...TjmQ%2fsNBI%3d

[XtraTN]

Re: No Backlight 40" Curtis LCD TV LCD4015AB

Should I also replace all the 14 capacitors on the board that feeds the ccfls?
Those are all labeled:

.1
SL6KV
33J

Where can I find this one? And how do you read these labels?

[budm]

Re: No Backlight 40" Curtis LCD TV LCD4015AB

33pf, J=5%, 6KV = 6000V.
Yes, I would replace them also, they are cheap.
http://www.mouser.com/ProductDetail/...bbB%2fhUHcI%3d

Just make sure to clean the board real well after soldering with denatured alcohol, you do want any contamination that may conduct when 2500V is applied to the circuits.

[XtraTN]

Re: No Backlight 40" Curtis LCD TV LCD4015AB

I noticed the one you linked me is rated 6.3KV. I already made the order but from what I remember its okay to use higher voltages for capcitors as long as the capacitance remains the same correct?

[drpj23]

Re: No Backlight 40" Curtis LCD TV LCD4015AB

Yep.

[XtraTN]

Re: No Backlight 40" Curtis LCD TV LCD4015AB

Just wondering how long does it take mouser to deliver? I chose economy shipping and it said estimated delivery would be on November 13, almost 2 weeks.. Is that accurate? If I knew I would of just spent an extra 3$ for USPS priority shipping and that usually takes 2-3 days..