RCA L32HD32D no backlight

[JAnoY]

The backlight in my RCA L32HD32D is not staying on. I turn the tv on and can see the glow of the backlight and the message "Please Wait" will appear for a few seconds but then the screen goes black, but I have sound. I've put a bright flashlight up to the screen and can see a faint image. Just not a very bright one. Using the flashlight, I managed to go into the menu and reset the tv to factory settings. Since that didn't help, I decided to replace both the control and the power/inverter boards. Still the problem persists. Thought my backlight was faulty so I checked the voltage at each connection and have voltage when set is turned on, but loose it after a few seconds. This happens with the new and old power/inverter boards. Any ideas on what the problem could be and how do I fix it?

[topfli8979]

Re: RCA L32HD32D no backlight

So you have replaced the power supply already?

[JAnoY]

Re: RCA L32HD32D no backlight

Yes. I've replaced the powersupply/inverter board (power supply and inverter board are integrated as 1 board) and the control board. I'm reading voltage to the backlight for a few seconds when I first turn the set on, then it drops off to zero. Happens even when the back light is unplugd and I turn the tv on.

[vinceroger69]

Re: RCA L32HD32D no backlight

https://www.badcaps.net/forum/showthread.php?t=9315

[JAnoY]

Re: RCA L32HD32D no backlight

Thanks for the link to https://www.badcaps.net/forum/showthread.php?t=9315 I've read that thread before but it didn't help me at all. That user didn't have sound as well as no picture. I still have sound and a picture, but my backlight isn't staying on and I'm trying to find out what is causing it.

[kevinm34232]

Re: RCA L32HD32D no backlight

When you say the control board do you mean the main board?

If you replaced the power supply and the main board you must have a bad or broken CCFL.

[JAnoY]

Re: RCA L32HD32D no backlight

Yes. I've replaced the control (or main) board and the power/inverter board. I'm having the exact problem with the original and the replacement components. What is the CCFL?

[kevinm34232]

Re: RCA L32HD32D no backlight

The CCFL's are cold-cathode fluorescent lamps that make the backlight in your LCD TV. They look like a smaller version of the 4' fluorescent bulbs you'd have in your kitchen. There are several of them lined up horizontally down the screen and if one or more is bad or broken it could cause the TV to go into shutdown.

You have to disassemble down to the panel and it could be tricky in order to see if all the lamps are coming on for the 1-2 seconds.

[JAnoY]

Re: RCA L32HD32D no backlight

Ahh. I've had it down to the lamps but did not remove or try and power the unit up to make sure all the tubes were coming on. I will try that. Where wold I look to buy some replacements if they're bad?

[JAnoY]

Re: RCA L32HD32D no backlight

Anyone know what size CCFL this RCA L32HD32D takes?

[tom66]

Re: RCA L32HD32D no backlight

The best way to know would be to measure them. You need to measure length and their diameter.

[JAnoY]

Re: RCA L32HD32D no backlight

I can measure the length, but the diameter is a tad tricky cause these lamps are small. I just want to make sure I get the right one. I can get a CCFL's ranging in size from 1.8mm up to 3mm, with increments of 0.2mm in between. (ie.. 1.8, 2.0, 2.2, 2.4...) Would each different size use different voltages? Could I use another size that's not exactly the same as the stock ones in my tv?

[tom66]

Re: RCA L32HD32D no backlight

Problem with different sizes isn't voltage or current but that they won't fit. The clips will usually only allow 0.2mm each way. I use these cheap ebay calipers. Maybe you have a friend you can borrow some from.
http://www.ebay.co.uk/itm/150mm-ELEC...item43addbf6d3