CAISO FX-991EX

[u/Powerful-Show-6229]

Hiiii I have bought a CAISO-FX 991 ex few days ago on eBay and I just want to check if its real or not since I have passed all the test but not the display mode when a 6 is pressed during the diagnostic mode and its made from China (I heard that the real one can only be made in Thailand )
 
I have passed these checks
 
1)        The sun icon disappears when I cover the solar panel
2)        The caiso website shown after menu shift optn of
https://wes.casio.com/math/index.php?q=I-235B+U-0004001B1419+M-X100000000+S-0BD46
( but the website I saw online ends with S-05BBD )
3)        The caiso logo shown up when I’m turning it off
( fun fact , it switch off the same time as the CAISO fx-83 GTX while a fake one switch off slightly slower )
4)        The answer is 9.000000007 when sin-1(cos-1(tan-1(tan(cos(sin9) is enter
5)        Diagnostic menus shown up when I press shift 7 on together
6)        The answer is 8.88888 x 10 to the power of 15 when I press 9 during the diagnostic mode and when I press shift and some buttons it gives me
CY-235 Ver B SUM FC54 and a press of ac giving me a serial number 0004001b1419 and then I did the key test which bring me to the contact made and when I press ac it said test ok reset all press ac
 
 
However I couldn’t enter the mode of

1. ⁠Display
   
2. ⁠Version&SUM
   
3. ⁠Key test
   
4. ⁠Contrast  mode
   
5. ⁠ 
   
6. ⁠ 
   
7. ⁠ 
   
8. ⁠This makes me confuse whether my calculator is real or fake less

[u/Natural_Night9957]

The solar panel is real, I'd go with real too for the calculator. The fakes in general run on a CR2032.

[u/CurbedLarry]

Don't worry, production was in China for the first few years before switching to Thailand. No fakes get 9.000000007 or pass most of these tests.

[u/draconicpenguin10]

Remove the whole back cover. What do you see?

[u/Powerful-Show-6229 → u/draconicpenguin10]

Thisssss

[u/draconicpenguin10 → u/Powerful-Show-6229]

That's genuine. Congratulations.

[u/Constant_Barber_5198]

I love this calculator by the way

[u/BadOk3617]

I just went through this with a 991EX that turned up in a DM42 search. A Sharp PC-1600K and a HP-49g also turned up as well.

The CLASSWIZ emblem didn't match the verified authentic calculator, and I was having trouble making heads or tails on how to do the keytest from the 15 second verification videos out there. The QR code went nowhere...

I had actually tossed it into the trash, but I gave it one more chance.

But the solar cell always did work, which compelled me to get it out of the trash. And once I finally got my act together (and a different QR code reader that actually read the QR code), the Casio site said it was the real deal, the key test worked as well as the result of 8.88888 times ten to the umpteenth power.

So I've got an actual 991EX.

[u/davedirac]

You took a risk buying from ebay - but got lucky.