When I got it, the description was "needs a new USB port, bottom plate loose". Turns out the thing must have taken at least one hard fall, as pretty much all the plastic holes for the bottom plate screws were broken, the plastic upper case had a crack near the power button and the USB port was in pieces. Must have not been the first hard hit the thing had taken, about a third of the knobs had hot glue in the inside to hold them on the encoders' shafts. Taking it apart, no signs of obvious damage to the PC, no evidence of liquid spills (wow) or magic smoke. Rubber surface was deteriorated, crumbs and dust between the pads and buttons, no surprise given the age.
Replacing a USB port was easy, the device is recognised by Live and boots up. All LEDs on, display working, encoders seem fine. Firmware 1.16, Boot Code 1.10. However, the pads...
The carbon sheet shows quite some wear, the PCB traces are clearly visible. I have used graphite paint before, so I think that can be fixed.
Trying out the pads on the PCB however reveals that it won't be that easy. When I simulate pad presses by shorting the traces directly, only about half of the pads show signs of life. The dead ones are mostly in the upper half, but not following a clear pattern - there is no row or column that is entirely dead.
Diving in further - the pads in a column all share a PCB trace - those appear to be fine, they all conduct from the bottom to the top. The rows are not connected directly: Two pads go through a diode on the back of the PCB, then they go through a common trace into OP amps. The diodes seem to be fine, at least according to my multimeter. I guess my next task will be testing those two SMD parts (LMV324M). Fun...
Still no idea what's wrong with this thing. My hope would be that it only got a hit that cracked a solder joint or two and that reflowing will fix it. If it is a crack in the traces of the multilayer circuit board, I don't know if will be able to find, let alone fix this.
Should this adventure be of interest to anyone (not sure why, if you're not a stupid as I am you'll just replace yours with a used Push 1 for $150), but if there is, I can take some photos. Or, should anyone out there have more information about the schematic and possible points of failure, that would be very appreciated (hello, Ableton
).