Casio PT-1 that needs repairing

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Posts: 1
Joined: Wed Jun 20, 2018 3:50 pm

Casio PT-1 that needs repairing

Post by kukskywalker » Wed Jun 20, 2018 4:26 pm

I recently acquired a Casio PT-1 at a fleemarket. As luck would have it, it doesn't work, and I'm hoping to be able to repair it. I have absolutely no experience with working with any kind of electronics, so I don't even know how to figure out what's wrong with it, but I was hoping somebody here might be able to point me in the right direction. I'll try my best to describe the problem. The keyboard has 3 different modes: poweroff, record and play. When I plug in the powersupply, the power LED lights on, regardless of what mode the keyboard is in (even poweroff). There's a distorted buzzing sound from the speaker for a few seconds, before it goes silent, and that's it. None of the keys or buttons do anything. The keyboard also runs on 4 AA batteries, so naturally I tried that too, but it seems the coil spring inside the battery case had broken off, and the previous owner had tried to solder on a new one. The new one eventually broke off as well while I was fiddling with it, and what's left of the original spring coil looks fairly corroded.
The circuit board doesn't look damaged (to an untrained eye anyway), there's a few spots with some kind of green ooze on the back of circuit board and on some of the components, but none of them seem to be missing or be broken (again, to an untrained eye). There's some rust on the speakerphone, and some corrosion or something around a microchip on the board.
I do realize I might be out of luck, because I read that the PT-1 might have a tendency to just c**p out. I should also note that the power supply I have is not the original one. The one I got is of the kind where you can change the polarity and voltage. The keyboard is rated at 6V and 0.8A, but the power supply is rated at 12A. I don't know if this matters a whole lot because I read that the device will call the shots as far as current goes, and that I wouldn't see any problem since the adapter has a higher current, and therefore will just have to do less work.
I do have a feeling that it's not a problem with the power, since the keyboard seems to be getting power (It even did when I tried using batteries with the broken coilspring, but again, what the h**l do I know.
Any help would be greatly appreciated.

Posts: 31
Joined: Sun Aug 20, 2017 1:13 pm

Re: Casio PT-1 that needs repairing

Post by coldwar » Fri Aug 10, 2018 9:50 pm

I had a blue PT-1 as my first keyboard and still have it :) My sis and I used to chase each other around with it on the Fantasy sound, hitting the high note. Not super sure about your particular power issue. I will have to dig mine out and pop it open this weekend and see if I can see anything obvious to suggest to ya. My initial gut instinct is that the little metal leaves under the power switch may be the issue, but will think on it some more and get back to ya.

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