This process will allow you to reset your filament nfc tag to a full configuration using an Android Device with NFC. If you don't have an NFC enabled Android Device or what something different I have an Instructable using an Arduino and NFC Attachment that can be found at this link:
Step 1: Read Your Card
Step 2: Read Your Data.
Once this screen is opened place your tag on the reader. You should get the highlighted red text. Please forward this information to me and purchase my eBay item at eBay Listing. I will provide the key to you through eBay, then you can follow the rest of the directions.
The alternative to the eBay listing is to use a process where a logic analyzer is physically attached to a chip inside of your disassembled printer and listening for the key. The basics of the procedure can be found by googling Da Vinci jr NFC Reset.
The eBay listing is a way for me to get your password, so that you don't have to purchase various electronic, learn to use them and take apart your printer and make connections to your printer chips. By all means if you have the desire and or the equipment get your own password go for it. I'm just providing an alternative.
Step 3: Known Issues
At this time the procedure below shown in the instructable linked below for 2.2.6 does not work for firmware version 2.2.7. At this time no one has reported getting anything to work to roll back from 2.2.7. on Soliforum.com there is a thread where someone shares a theory on rolling back using the 2.2.7 firmware that you can try. Other then that please just experiment and if you are successful post a comment or let us know on the forum.
Fix Found -------- Firmware can now be rolled back
See Link Below for Rolling Back Firmware to something newer:
At this time we are having issues with getting the correct reset values for firmware version 2.2.6. Just be warned that this firmware may be recording something on the tag and length and giving errors when the number ends up higher. We are working on figuring out what it is recording and if there is data set that will reset it, but at this time we have not figured it out. It seems to happen to chips that have been run all the way to empty, do not run any chip you want to reset to empty, reset before you hit zero. Also, if you have the choice don't upgrade to firmware version 2.2.6 if you want to reset chips.
Now Change Firmware to Older Version for Reset Tags to work and reset over and over again.
It is known that on at least one Android device the phone identified the tag as a MiFare Ultralight instead of what it actually is (an NTAG213) as can be seen in the picture above. While the information included in the picture can be forward and the key can be found from this info, the app was not able to use the password due to the device identifying the tag as the wrong type. In this case the tag was taken to a different device where the key was then used successfully. If your device identifies the tag incorrectly be warned it may not be able to use the key to read and rewrite the tag. You may need another Android device or something else like an Arduino and NFC shield to read and rewrite.
When the last 4 digits of Page 2 reads as follows:
 : XXXXF8FF
This means that pages 3 to 15 of the tag are irreversably locked and can't be rewritten. So, Page 8 which has the color/temperature setting can't be reset. And pages 10 (0A in hex) and 11 (0B in hex) which has the original reel length can't be increased. Page 20 (14 in hex) has the length left on the reel, so that can be reset if your tag has been locked. At this time we have been unable to successfully rewrite pages 20 to 23 (14 to 17 in hex) in a way that the printer does not get an unrecognized spool error. I would recommend trying a different tag and seeing if it has all pages unlocked and sending the info for that tag to get that tag key.
This situation has only been encountered one time. All other known tag reads have shown values of 0000 for the last 4 digits of Page 2 meaning none of the pages 3 through 15 are locked.
Step 4: Enter the Key
One the main screen in the top right corner select the key icon.
Step 5: Select NTAG21X
Select the NTAG21X from the list.
Step 6: Add a Key
In the top right corner click on the key with plus sign.
Step 7: Enter the Key
You can enter anything for the name for the key. Enter the key in the password area just 8 digits no spaces.
Step 8: Turn on the Key
Make sure after entering the key that in the main key screen the key you are using is the only one active.
Step 9: Reading the Card With Key
Once back at the main menu again select the NTAG Option.
Step 10: Reading the Authenticated Card
Once in the read screen ensure that the box next to Authenticate is checked and then place your tag where it can be read and it will read the entire content of the tag and output it as shown in the picture. At this point you should be able to write using the boxes at the top of the screen to change the information on the tag.
The second line has the PACK it is a 4 digit number. This is the number I request when giving you the key. In order to continue with the effort, in the hopes of one day creating usable tags from blanks we need to figure out how the PACK is calculated, so the bigger the data set the better chance we have or figuring it out. That is why I ask for the PACK to get a significant sample size to look for the pattern.
Step 11: Values to Reset
Page 8 has the color and extrusion temp in it. It is the 5th and 6th digit of number. Right now only 2 temperatures are known 191 and 210, so in the pic are the codes for each. Temp appears to be set by color, so changing the color is the only way to change the temp.
Page 08: 5A505000 For Green and 210 Degrees
Page 08: 5A504500 For Olivine and 190 Degrees
Page 0A and 0B set the original spool length reset these values to the default 200 m value.
Page 0A and 0B: 400D0300
Page 14 has the Remaining Length on the Reel and this should be reset to the default 200 m value.
Page 14: 400D0300
Pages 15, 16 and 17 change as the reel is used and are most likely just countdowns that are used as a checksum of the length. These should be reset to the default values.
Page 15: 081F3154
Page 16: 50B1E0CE
Page 17: 52E74F76
If you run into trouble start by trying a different color setting in Page 8. If that doesn't work change all pages 8 to 17 hex to the values that match the picture.
Leave a comment if you have questions or send me a message.
Step 12: Known Temp Color Pairs
Page 8 - Byte 3 is the color/temp
5A 50 4B 00
In page 8, all possible color settings found while plugging and chucking, on firmware 2.2.0. Again Page 8 3rd byte
5A 50 42 00
32 CLEAR RED
34 BOTTLE GREEN
35 NEON MAGENTA
36 STEEL BLUE
37 SUN ORANGE
43 NEON TANGERINE
48 NEON GREEN
49 SNOW WHITE
4A NEON YELLOW
4D GRAPE PURPLE
4F CLEAR YELLOW
50 CLEAR GREEN
51 CLEAR TANGERINE
53 CYBER YELLOW
55 CLEAR BLUE
56 CLEAR PURPLE
58 CLEAR MAGENTA