This guide assumes you’re familiar with NTAG215 chips, and the processes used to create them. If you’re not familiar with them, please visit Doing amiibo on a dime to learn about NTAG chips.
Most of the NTAG215 chips you purchase will work fine. I’ve purchased over 200 chips online, and had issues with only a select few. I estimate a 95% success rate with functioning NTAG215 chips, but sellers on Amazon have a 100% success rate.
If a chip isn’t working and you can rule out the “Miswrite” possibility, you’re probably shit outta luck. These chips are cheap by design, so your best bet is to replace them and start over. If multiple chips are having issues, the problem is your NFC writer.
Common causes of NTAG215 issues
Cold – NTAG215 chips often ship in harsh weather. This is generally the leading cause of broken NTAG chips – they often ship from China, which has very low standards for shipping.
Bent – NTAG chips are like any other, and can’t be bent without breaking the chip. If you’ve tried to wrap it around something curved and are having difficulties, odds are you’ve irreparably broken the chip.
Miswrite – If you’ve written to the NTAG215 chip with Tagmo and are still having issues, then it’s likely that you’ve written using a weak connection. This could be caused by a number of things, but generally you’re either not putting the chip close enough to the writer, or there’s something obstructing the chip. Try writing to the chip again (with the same bin file, or a different bin file of the same amiibo) but do it in a different spot.
Dud – Sometimes chips just go bad. These are thirty cents a pop, so you won’t be set back too much if one of them goes bad – just make sure you’ve got backups of all your amiibo files using our Tagmo guide or iPhone guide, and write it to another blank chip.
Amiibo Doctor 
Have you ever encountered a coin casing that was too thick for a joycons to read through?
Bought 50 coin tags that came with casings and I have no problem reading the tags with tagmo
And no problem reading the tags on my 3ds
But on my switch/joycons I have to sorta grossly angle the coin on the edge of the joystick for it to read
I’m guessing it’s the coin case as it as no problem reading the tags without the case
But it’s weird that the cons can read a normal amiibo just fine but struggles with a simple coin case?
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Yeah, I’m not entirely sure why they made the joy-cons that way but it’s a fairly common problem. I’ve had amiibo cards that came in a perfectly normal plastic card sleeve that couldn’t be read unless I took them out.
It’s really a problem with the joycon construction as far as I can tell.
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