The best way to establish whether fake or genuine, is to remove the back. The fake model has two, button cell batteries and the solar cell is not connected to the circuit board (pulls straight out, with no connectors). The genuine model has only one battery and the solar cell is connected. Another good way is to scan the QP code. This facility doesn't work on the fake model, all you'll get is √2, or something similar. The fake model frequently displays Math Error when you attempt to solve quadratic equations or inequalities. Try x²- 31x +72 =0. The genuine calculator solves it; the fake version displays Math Error.
My calculator QP code is given "An invalid parameter is specified" when it redirect you to Casio site but it solved the quadratic problem you provided though. have FE exam soon and worry if need new one.
You should be okay. I'd advise undoing the screws and removing the rear cover to check how many batteries it has. The genuine version has only one battery, and the solar panel is connected to the circuit board (not connected on the fake versions and these have two batteries instead of one).
Put your finger over the solar cell and look to see if the dot on the top right hand corner of the screen disappears. If it does, the solar cell is functioning and your calculator is likely to be genuine. The easiest and best way to check is to undo the four screws and remove the back of the calculator. You can then confirm whether or not the solar cell is connected. If it drops out, it's fake and your calculator is counterfeit. Also, look to see how many batteries are used. Most fakes take two batteries, where as the genuine models have only one and this is accessible through a panel on the back of the calculator. Fakes often have batteries that can't be accessed by this panel - you have to remove the back. If you purchased on eBay, demand a refund and you'll probably get your calculator for nothing once you open a case against the buyer and allow eBay to step in on your behalf.
Yes, but not with every quadratic possessing real roots. Try solving: 5x² - 31x - 72 = 0. The counterfeit copy can't do it, the genuine one can. Also true for inequalities, and even the ratio solver doesn't work as it should! Try solving 45 : 305 = 180 : x. The counterfeit copy displays Math ERROR, the genuine one says x=1220.
@@aviendzoneyt8563 Try covering over the solar cell and looking at the small, black dot at the top right-hand corner of the LCD display. If it goes out, the calculator is likely to be genuine. Another good way to check is to take the back off. The fake models take two batteries and the solar panel (fake) isn't connected to the circuit board. The genuine item takes only one battery and the panel is connected by wires. If your one is genuine and, after carefully entering that equation several time, it still can't solve it, then I'd take it back to where you bought it from or explain the situation to Casio UK. They may offer to repair it free-of-charge if this is a fault they're aware of. If it's fake and you purchased it from eBay, you are entitled to a full refund under their consumer protection policy. eBay claim to prohibit the sale of counterfeit goods. You may well be given a full refund and told to keep the calculator rather than return it.
The best way to establish whether fake or genuine, is to remove the back. The fake model has two, button cell batteries and the solar cell is not connected to the circuit board (pulls straight out, with no connectors). The genuine model has only one battery and the solar cell is connected. Another good way is to scan the QP code. This facility doesn't work on the fake model, all you'll get is √2, or something similar. The fake model frequently displays Math Error when you attempt to solve quadratic equations or inequalities. Try x²- 31x +72 =0. The genuine calculator solves it; the fake version displays Math Error.
My calculator QP code is given "An invalid parameter is specified" when it redirect you to Casio site but it solved the quadratic problem you provided though. have FE exam soon and worry if need new one.
You should be okay. I'd advise undoing the screws and removing the rear cover to check how many batteries it has. The genuine version has only one battery, and the solar panel is connected to the circuit board (not connected on the fake versions and these have two batteries instead of one).
@@davidjenner5665thanks
Were same, mine also shows invalid parameter but solved the equation? Is my 991ex genuine?
Yes. Only QP Code seems is not working
Put your finger over the solar cell and look to see if the dot on the top right hand corner of the screen disappears. If it does, the solar cell is functioning and your calculator is likely to be genuine. The easiest and best way to check is to undo the four screws and remove the back of the calculator. You can then confirm whether or not the solar cell is connected. If it drops out, it's fake and your calculator is counterfeit. Also, look to see how many batteries are used. Most fakes take two batteries, where as the genuine models have only one and this is accessible through a panel on the back of the calculator. Fakes often have batteries that can't be accessed by this panel - you have to remove the back. If you purchased on eBay, demand a refund and you'll probably get your calculator for nothing once you open a case against the buyer and allow eBay to step in on your behalf.
Nice
Thank you so much for saving our valuable time 💚
Thanks a lot. I'm gonna buy this same model soon. Will surely check using this method.
ruclips.net/video/Ac0VERs_x2o/видео.html
Thank you sooooooooooooo much 😅😊
For QR code Mode setup + 0
this is not true, even the third copy models do this
What to do then?
@@MentionmeIfuGaeruclips.net/video/l7WthOcg1Yo/видео.html
(this guy shows how to tell the solar power is fake and differences visible in test mode)
Yes, but not with every quadratic possessing real roots. Try solving: 5x² - 31x - 72 = 0. The counterfeit copy can't do it, the genuine one can. Also true for inequalities, and even the ratio solver doesn't work as it should! Try solving 45 : 305 = 180 : x. The counterfeit copy displays Math ERROR, the genuine one says x=1220.
Hey my Casio calculator can do the ratio but cant solve the quadratic it says syntax error
@@aviendzoneyt8563
Try covering over the solar cell and looking at the small, black dot at the top right-hand corner of the LCD display. If it goes out, the calculator is likely to be genuine. Another good way to check is to take the back off. The fake models take two batteries and the solar panel (fake) isn't connected to the circuit board. The genuine item takes only one battery and the panel is connected by wires. If your one is genuine and, after carefully entering that equation several time, it still can't solve it, then I'd take it back to where you bought it from or explain the situation to Casio UK. They may offer to repair it free-of-charge if this is a fault they're aware of. If it's fake and you purchased it from eBay, you are entitled to a full refund under their consumer protection policy. eBay claim to prohibit the sale of counterfeit goods. You may well be given a full refund and told to keep the calculator rather than return it.
for Chinese Viewers
this is not gonna work on fx991cn