LED edge-lit backlight

[Alex Eisenhut]

My Breville toaster oven finally struck out the third time yesterday. The LCD backlight went dim a long time ago, but now the door closing spring snapped apart quite loudly. So I took the thing apart. It's a monster with a lot of screws and stuff.

I dug down to the control PCB with the LCD.

I pulled the backlight out from under the LCD.

I took that apart as well, it's a piece of transparent plastic with silvered edges and diffusers, lit by a tiny PCB with 4 blue LEDs. One is burnt out and the other 3 look dirty and charred a bit.

Super awesome, but I am not sure what LEDs I should get, what viewing angle is best? I'm guessing as wide as possible to keep the light even.

The LED driver on the PCB doesn't seem that complex, a transistor switching a 470 R to ground. I guess this means you can't have more than about 10mA total for the 4 LEDs.

I just want to solder and build this up once, what LEDs should I use? Wadda ya think of this:

https://www.digikey.ca/en/products/detail/kingbright/APT1608LVBC-D/5177434

Has anyone ever seen a PCB like this, 52mm x 2mm wide? I feel it's even smaller than a LiPO protection PCB. I don't suppose it's a standard thing I can just buy?

[Ordinaryman1971]

You can use the LEDs that are used to replace backlight on older monitors. I've got few of those from ebay. You can cut them every three LEDs and they are powered with about 8V-12V.
on ebay search for: Universal LED Backlight Strips Kit 15~24 CCFL LCD Monitor To LED Replacement
Or you can pull the LEDs from broken screen... I see that the ones you have are on very thin flex. That could be better solution possibly.