4 replies to this topic

[RobJDean185]

My wife, a maths teacher, has handed me a project/challenge in the form of a Casio FX-9860 GII (USB Power Graphic 2) which came back from a student with the screen displaying the main menus but no key responses. After some research I came across the thread on these forums discussing a similar problem in 2013 which I followed as far as I could but the problem persists. Rather than resurrect that thread I'm trying a new one but the relevant part was at http://community.cas...k-help/?p=59002

 

After a crash course in the basics, I've done everything I can find to do so far and still have the same problem - I wondered whether anyone had any further suggestions before we consign what seems to be an almost working piece of kit to the dustbin (or get the screwdriver out which usually ends up being the same thing):

 

• I've used the bootcode updater (because it wasn't possible to set USB mode with the keys) and have successfully updated, twice to v2.09 of the OS. However, on reboot, the same problem exists - no keys give a response; sometimes the screen shows the main menu after boot, other times it shows different content (not corrupt just a screen for equations or something like that).
• The F2+4+AC/on+Reset sequence then '9' and 'X' works properly, so the key pad is not physically disconnected. I have also found OPT+EXP+AC/on gives the 'Diag Mode, Factory only' view; 1+3+AC/on brings up the Reset screen so there are a range of keys that are functioning when the Casio is accepting them, but when the screen is displayed, no keys give any response.
• If Power is Off then pressing AC/on brings the view back.
• If the power is on and something is displaying, plugging in the USB cable gives the USB mode Select options but again keys F1 etc do not respond.
• I've tried twice to use the bootcode updater to install the older v2.04 OS but that reports 'Update Failed'.
• The student is insistent that they haven't dropped or otherwise done anything to the calculator (no way to check but that is the background provided and there is no external damage).

 

Thanks for the guidance from these forums so far as it's been fun to investigate - and thanks in advance for any more ideas or pointers that might help actually resolve!

 

RD.

 

[anon34]

For your information, the calculator being able to enter diagnostic mode (in this case, bootcode updater) does not necessarily means that no buttons is broken, especially in case entering that requires to hold many buttons at once.
See for example this topic, where the original poster's calculator have broken keyboard, but still able to enter diagnostic mode. If all you've done on the keyboard is pressing multi-key combinations, that doesn't implies that the keyboard is not broken.
Try: Pick a fully functional calculator (9860GII in your example), hold one key (not used for enter diagnostic mode / bootcode updater), and then use the normal method to enter diagnostic modes. If it works, then the keyboard may be actually broken. So, consider disassemble the calculator (warning: may break the calculator!)
I think if the OS can be updated, it is not software error, instead it may be hardware error.

Disclaimer: I don't have any calculator with built-in programming ability (e.g., 9860GII), so I may not be correct.

[RobJDean185]

Good call - the important bit in that referenced thread is 'Stuck Key'. I disassembled the unit and found that someone had allowed a battery to leak but only cleaned out the battery compartment. Although all visible parts were completely clean and the keys all moved completely freely, there was a pool of slightly sticky liquid on the back of the keypad, the keypad ribbon cable to the motherboard and contamination on the rubber pressure pad. After cleaning that off with a decent cleaning solution, the entire unit works normally.

 

Thanks for the suggestion. I couldn't find a decent breakdown of the process for taking this item apart so I took some photos and I'll post those separately in case anyone else needs them.

[RobJDean185]

Here's the instructions on disassembly. http://community.cas...ing-fx-9860gii/

[aj026827]

Thank you RobJDean185! I had this exact same problem and it was solved with the exact same solution, cleaning the leaked batteries off the back of the circuit board. Your instructions for disassembly were very helpful. Now my calculator works. Thanks!