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Box light from broken monitor Answered

Hi, this is my first DIY project! I'm trying to convert a broken monitor into a panel light. I've successfully taken it apart, removed the LCD portion and retained only the backlight (with diffuser), which works fine. However, I have no idea how to keep the backlight on without a signal on the DVI/VGA ports, which the monitor's circuits clearly expect. When I press the power button, the backlight switches on, stays on for about 30 seconds and then switches off, presumably because there's no signal from the VGA/DVI ports.

Model: T215HVN01.0

Data sheet: https://datasheetspdf.com/pdf-file/789046/AUO/T21...

What do I need to do to keep the backlight on as soon as the power is on? I have all the necessary tools (wires, breadboard, assorted resistors and capacitors, soldering iron, etc.). Do I need to have all the circuit boards that came with the monitor, or can I somehow make do with just the yellow board which takes care of the current and voltage to the backlight LEDs?

I'm putting some pictures of the circuits here for reference... If I need to zoom in/focus on any specific part of the circuit boards, please let me know. Hoping someone can guide this electronics noob. :)



9 days ago

Actual spectrum output is probably very cool-white. I wanted to modify a panel in the past, but it's way easier to just make one from scratch - BTW.

Jack A Lopez

13 days ago

The LED backlight is described briefly on page 17, section 5.2, "Backlight Unit."

The pinouts for the connector that powers the backlight are revealed on page 25, section 7.2.1, "LED Pin assignment."

Also I think I can see this connector, on the big yellow board. It is on the left side when the mains power connector is on the bottom. It might be labeled, "CN802."

On the right side of the big yellow board, there is connector between the yellow board and a smaller, square, green board. This connector is labeled, "CN902."

I am guessing the big yellow board does power converting, and maybe also the driver for the LED backlight.

I am guessing the square green board is the brains of the operation, and also it does all the heavy signal proccessing needed to drive the display.

Another guess is the signals to dim, or turn off, the backlight, are present on those wires in connector "CN902". On the board those wires are labeled, "DIM" and "ON/OFF", and they are yellow and green respectively.

The strange thing is, I do not see any ICs on the big yellow board that look like they are obviously doing the LED driving function. But that might be because I cannot see the other side of the board, or the ICs mounted to vertical heat sinks.

Anyway, that is a suggestion to you: That you should try to find what is doing the LED driving function. I expect it will have wires trailing away to the LED backlight (via connector CN802) on one side, and maybe have wires trailing away to "DIM" and "ON/OFF" (part of connector CN902) on the other side.