Casiotone CT-320 troubles

TL;DR, got a free keyboard a ways back, and problems with both a mess of keys not working, and difficulties with the power supply port.

i ended up with this keyboard that is apparently only a year younger than i am, and has probably spent the last five years in storage, and who knows how many years prior in what basically amounts to having been sitting in a barn or similar outbuilding. but anyway, it was free, and figured i could try something with it. turns out the AC power cable is a bit janky, and i’m still sorting that, but can get it to work some of the time. fairly sure it’ll still work via batteries if needed, but not the biggest issue yet. turns out, once i get power to it, there’s an entire octave’s worth of keys not working.

grabbed a screwdriver and carefully disassembled the whole thing, clearing out copious amounts of dust, debris, and random bits of what appeared to be straw and peacock feather. wasn’t kidding about it being stored in a barn. the PCBs are all still 99% intact, as are the cables connecting everything. so cleared that stuff aside and popped off the key contact boards. pulled the button contact strips as well, and tested pieces- the contact strips aren’t the issue. but i can’t get any sort of response from the first 12 key spots on the middle key contact board. so… what next? is there a way to test the key contact board, is there a suitable replacement? or do i just accept this isn’t gonna work, put the thing up for parts somewhere, and buy something else if i want a working keyboard?

Well if you don’t know much about diagnostics you would be better off buying another if you really want this model. £60 on is not a lot of money and you could easily spend some of that £60 on tools like a multimeter, soldering iron etc…

But what you will find is that if a group of keys won’t work it could be because there is a common connection between all of these pads and there’s a break in the PCB track which supplies the voltage to these pads.