backlight of a lcd screen - how to get it to turn on?

[con.fuse.d]

Hi all, I have a lcd backlight and I want to plug it into a 12v supply, but I don't know how the wires go. Any ideas?

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[Nigel Goodwin]

It's normally not that simple, there are usually control signals in and out as well.

 

[con.fuse.d]

Well 2 of those wires have to be for electricity, right? And then can't I just short the other 2, or somehow send an "all-is-good" signal so it works?

In any case can I just wire the backlight panel to a transformer?

**broken link removed**

 

[Nigel Goodwin]

Well 2 of those wires have to be for electricity, right? And then can't I just short the other 2, or somehow send an "all-is-good" signal so it works?

Two will certainly be ground and power, but the others may not be simple ON/OFF type signals, but more likely some kind of pulsed data coming back from the inverter (if there's a return), an analogue input for brightness, and possibly a logic signal for ON/OFF.

In any case can I just wire the backlight panel to a transformer?

I wouldn't have thought so - it's fairly complex.

What are you trying to do with it anyway?.

 

[con.fuse.d]

an analogue input for brightness, and possibly a logic signal for ON/OFF.

Is there a way to mimic that?

What are you trying to do with it anyway?.

I'm gonna use it as a lighting panel for macro pictures.

 

[KeepItSimpleStupid]

Is there anything identifiable on the board itself. IC numbers, etc. Do you know what it came out of?

Here SEM2006 INVERTER Service Manual free download,schematics,datasheets,eeprom bins,pcb,repair info for test equipment and electronics is an inverter schematic, probably not a laptop.

This particular model suggests that the control signals could possibly be Power, PWM (brightness), Ground and On/Off.

 

[con.fuse.d]

Is there anything identifiable on the board itself. IC numbers, etc. Do you know what it came out of?

It came from an old LCD, 15" not a laptop display, and I discarded the rest of the board. I don't even remember the brand, silly me...

This particular model suggests that the control signals could possibly be Power, PWM (brightness), Ground and On/Off.

Should I test it? Just got to figure which is which. Is there a way to discover that by where the wires connect in the board? I could take a close picture of the board.

 

[Nigel Goodwin]

Ground is obvious, so that's easily identified - power is as well, it will go the +ve end of the large electrolytic(s) on the board. The other connections are somewhat more difficult.

 

[Mr RB]

Downlaod and check the datasheet for the IC, and see if it has something as simple as an "enable" pin.

And like Nigel said the power and ground will have large traces and go to a large cap.

 

[Whkrems]

Backlights of a 42 inch lcd screen how to power them

I have a LG Philips LC420Wu6 from 42 inch tv. I removed cracked front LCD panel and used the whole tv for shoplight over workbench for awhile then got replacement and fixed the tv, now I have the old LC420WU6 with backlights and inverters, 2 wires from each inverter. What can i use to power the inverters?
It worked great for work light.