Backlight transfo removal.

sammy · Post by **sammy** » Thu Nov 16, 2006 4:29 pm

I've got an lcd that I want to led mod. I already took out the light-tube but I got to know where I can connect the leds. I know you got to remove the transformer but I... Dunno where it is... I'm quite ashamed

but I just don't want to mess up my board.

I've got some pics:

This is where I think the current flows. The red and blue wires are from the light tube.

I don't know what this 'block' is but it looks like a transformer. The red and blue wires are where the tube is connected like I said before

But then you got these suckers. Is this the actual transformer perhaps? I don't have a clue but it sure looks like one. The other side is connected to some smd resistors and eventually to a tiny ic as you can see on the last picture.

I got to know what I can remove and where I should solder my leds on. The pictures are very bad but it's because I used my webcam.

Any help would be great!

Rellizate · Post by **Rellizate** » Thu Nov 16, 2006 5:24 pm

Just use a multi-meter to find 5v, then use that place.

jedi knight · Post by **jedi knight** » Thu Nov 16, 2006 5:48 pm

You can tap +5 volts off of the 7805 on the mobo. For ground you can use one of the grounding strips.. To remove the transformer just desolder the 6 leads. There is 2 of them on one side and 4 on the other. The transformer is the box at the top of the mobo. Hope that helps

sammy · Post by **sammy** » Fri Nov 17, 2006 11:37 am

Thanks, but can I also remove the two other inductors?

jedi knight · Post by **jedi knight** » Fri Nov 17, 2006 3:22 pm

Oh crap I just realized that you have a 3rd party screen. I don't know if the inductors can be removed or not.

sammy · Post by **sammy** » Fri Nov 17, 2006 3:28 pm

I didn't remove them yet

But anyway I have another problem now... It's rather strange as well. I went out to buy 3mm white leds. I bought 8 (they costed me 2$ a piece) and I tried them out just now... Turns out they are blinking and they only work at 12V... Minimum...

jedi knight · Post by **jedi knight** » Fri Nov 17, 2006 3:59 pm

$2 each? Thats crazy! 12 volts is a crazy voltage too. Have you tested them at another voltage?

sammy · Post by **sammy** » Sat Nov 18, 2006 10:10 am

Yes I did. 9V didn't work, 6V didn't work... I'll try them at a higher current later on but I haven't got any other transformers laying around.
But the main problem is that they blink! I hate my electronics store, last time I bought 6 buttons for my portable and only 4 worked.

EDIT: I went back to the store and apparently the sales lady gave me the wrong ones. I gave her a datasheet to tell her which ones I wanted and she acted all suprised. The leds she gave me where for usage in cars altough I clearly stated to her the first time that they were for low voltage use

I tested the new ones and they work great at about 400mA. The input current of the battery I'm using is 1400mAh so that should work great!