5 replies to this topic

[TheFallen018]

Hey guys, I was wondering if anyone has run into a problem like this. 

I've got an fx-9860GII, but all the buttons on the same row as 7 or below don't work. All the other ones work fine, but without the bottom buttons I can't use the calculator. Even the on button doesn't work, so the only way I can get it to turn on is if I take the batteries out and put them back in. 

I've taken it apart carefully, and found that there was a bit of leakage from a battery on the back of the keyboard board. I cleaned that off, and washed it down with isopropyl alcohol, but when I turned it on I had the exact same problem. Nothing had changed. I also tried doing a reset from the menu, as that's one of the few things I can do, but that didn't help either.

Does anyone have any ideas on what could be causing it? Thanks

EDIT: Just noticed it typed fx-9869GII in the title. That is meant to be fx-9860GII. (Sorry)

Edited by TheFallen018, 15 November 2018 - 05:28 AM.

[GodOfCows]

Do you have warrenty? I would defiantly see if I can replace it for free before you start tinkering with it, voiding warranty. If you can't get it replaced for free, then you could try giving it a good clean. I've seen that 50/50 of water and vinegar is a good solution for removing battery acid. Look it up before you do anything (don't take my word on the water and vinegar, look it up!)

[TheFallen018]

Do you have warrenty? I would defiantly see if I can replace it for free before you start tinkering with it, voiding warranty. If you can't get it replaced for free, then you could try giving it a good clean. I've seen that 50/50 of water and vinegar is a good solution for removing battery acid. Look it up before you do anything (don't take my word on the water and vinegar, look it up!)

Unfortunately it's not covered by warranty, and hasn't been for a long time. I've already done the vinegar and water thing, but it didn't seem to help. 

Edit:

So, I took it apart and checked the PCB traces using a multimeter, and found that about 6 of the traces were broken. After carefully soldering some copper wire on to the traces to join them I managed to create a different problem for myself. None of the keys work anymore, but I think that's because one of the buttons I reconnected is stuck down. If I hold down 1 while starting, it will go to run-mat in the main menu, so the button is working. Is there any way to find out what buttons are stuck?

Edited by TheFallen018, 15 November 2018 - 12:44 PM.

[GodOfCows]

I got no idea on how you'd be able to see which button is stuck, without checking each individually. I have an idea, later I might be able to make a program to see what button is stuck, but I'm busy right now, I can probably give send it out tomorrow.

The idea is to make a program which will say what button is currently is pressed (which is technicaly the stuck button), and you'll get your answer . You say that you can get to a program when you first start the calculator so you'll defiantly be able to use it. tell me if this sound good, and I'll make it but it'll take time (not like its hard, I just don't have time and don't have access to a windows pc) or you can make it. 

In any case, good luck 

[TheFallen018]

I got no idea on how you'd be able to see which button is stuck, without checking each individually. I have an idea, later I might be able to make a program to see what button is stuck, but I'm busy right now, I can probably give send it out tomorrow.

The idea is to make a program which will say what button is currently is pressed (which is technicaly the stuck button), and you'll get your answer . You say that you can get to a program when you first start the calculator so you'll defiantly be able to use it. tell me if this sound good, and I'll make it but it'll take time (not like its hard, I just don't have time and don't have access to a windows pc) or you can make it. 

In any case, good luck 

Hey, that sounds great, but I can only press one button before it freezes. If I hold down 1, it goes to the RUN.MAT on the main menu, but then I can't do anything. If I could open the program with a single button, that would work amazingly. Also, I have no idea how to program for the casio, so I doubt I could do it

Edit:
Hey, don't worry about the program. You're a legend for offering.

I think I found the problem with the stuck keys. There was a bit of dust between two of the solder joints for the ribbon cable that was shorting some power rails, emulating a key press. I fixed that, and after a bit more tinkering, I managed to get things working. I'm almost there. The AC and the (-) buttons are still not working, but the pads on the board are completely gone for those ones. I'm thinking if I get a silver conductive pen, I should be able to use that to replace the pads. With any luck, that should get me a working calculator

Edited by TheFallen018, 16 November 2018 - 11:34 PM.

[GodOfCows]

Good job on the electrical side, I would be lost with my terrible tinkering. What I meant with the program is since you can hold down one button and go to a program, you could do that for a different key and open a add-in program. Anyway, good luck on fixing the calc, it sounds like your getting there  .