Help Repurposing an LED Sign Panel

[TheGalantOne]

Hello Everyone,

My friend owns a store and his big LED sign went bad. Probably the main board. Well we took it apart and found the display was assembled in separate panels. I have a couple of these panels and was getting ready to strip them down for parts. Then I realized to use the LED Matrixes with an Arduino I was just going to have to recreate a board very similar to the one they were already on. So now I am trying to figure out how to use the panel as is.

I can only see the traces on one side of the board since the other side is covered in LED Matrixes. If that wasn't bad enough it is a multilayered board so I really only get a small view of the circuit. The board seems split in two halves each with a 14 pin input and 14 pin output, wich allows you to chain them together. I would love to figure out what these 14 pins do. I was hoping some one could look at the material list below and give me an idea. For example the CMOS Octal Bus Buffer. Are they using a standard bus architecture I can read more about?

Hope someone can help.


(2) 14 pin inputs, (2) 14 Pin outputs, Black 12AWG Ground wire, Red 12AWG , Orange 12AWG VDD Power

Qty	Parts On Board (Chip number then Data Sheets found)
20	8x8 Bi-color Led matrix
20	A6277x 8-Bit Serial Input Constant Current Latched LED Driver.
2	74HC240D CMOS Octal Bus Buffer
2	42Z4XRJ-HC14 possibly an SNx4HC14 Hex Inverter
16	IR44SH-4L2N-F7304 possibly an IRF7304 HEXFET
2	MAX7000 EPM7032
4	14 pin connectors
?	Lots of little resistors on the LED driver chips

 

[AnalogKid]

P.h.o.t.o.s.

 

[Harald Kapp]

Without circuit diagram - nearly impossible.
You may have to sacrifice one panel, remove the LEDs and trace the connections on both sides (hopefully and likely the board is double-sided only) to create a schematic from the pcb. Here's one guide how to do this. Other methods are possible, too.

 

[TheGalantOne]

Here are some photos. You can't read the text but if can give a better vision of the big picture.

Thank you for any advise you can offer. I know I could just buy a more modern and easy to work with panel. This is more of a challenge project that I am hoping to learn from.

 

[TheGalantOne]

Without circuit diagram - nearly impossible.
You may have to sacrifice one panel, remove the LEDs and trace the connections on both sides (hopefully and likely the board is double-sided only) to create a schematic from the pcb. Here's one guide how to do this. Other methods are possible, too.

That is such a good guide. There is so much there, I just quickly reviewed it and learned a ton. I'll do a full read over the next few days. My hope is I can apply power to the board and just start passing square waves to some of the pins on the bus until a light comes on. I uploaded some pics in another post. Maybe there is enough information there so save me from desoldering. If a can't getting working that way I will follow that guide, after all I am doing this as a learning exercise and will probably learn the most from truly tracing it out.