Greenstar Teardown

I got myself an old John Deere Greenstar RE67542 control panel, saved from e-waste. (The previous owner had himself saved it from the tip too). I wonder what's inside...

Lovely big buttons with a solid brown plastic case. The case is about 4cm deep, plenty of space to repurpose it for other things.

Unremarkable back, though has nice brass mounting holes and a solid connector. Notice the speaker to play tunes.

Opening it up (lots of torx screws), we get the bare keypad which goes directly to the back PCB via ribbon.

The LCD is large, perhaps 6"? It's dot matrix and backlit (assuming the CCFL still works). The whole front PCB is dedicated to driving it.

It looks like this whole board design came from the LCD maker, Three-Five Systems Inc. The KS0103 ICs appear to be made by Samsung, with their pre-1993 logo.

Next to the DANGER: HIGH VOLTAGE warning emblazoned in copper, we find some high voltage caps with silicone looking goop. Is it high voltage potting of some sort? I guess this is the LCD backlight upconverter.

The back PCB has the main control circuitry. Fairly plain on this side

Behold the guts of it

Appears to be a Motorola 68HC11 CPU, and also a large Intel chip?

The external connector has these interesting brass components, they appear to be some kind of protection