topic Re: MF644Cdw bought from Amazon (sold by Amazon) can't register, S/N rejected in Office Printers

MF644Cdw bought from Amazon (sold by Amazon) can't register, S/N rejected

Ericsan — Mon, 09 Mar 2026 18:23:02 GMT

Hello, I bought my MF644Cdw more than 2 years ago (June 2023) and it's been working mostly fine except for a pesky constant update of the Bonjour name, so I would have to delete/re-add the printer when using AirPrint.

I found out this was solved in a firmware update and realized I had never updated the firmware... Only to discover that it requires admin user/password codes, which I don't remember setting (and if I did, I forgot them).

The documentation says contact Canon support if you need to reset them, but in order to be able to do this I had to first register my product. I remember trying to do it back when I bought it, and it failed, and I gave up. So, I tried again, and it rejected my serial number. I know the number is correct, but it doesn't match the expected pattern which is 2 digits, 2 letters, 5 digits -- My serial number is 33C followed by 5 digits.

The printer was sold by Amazon directly (not a third party vendor) so I would expect it to be legit.

So here are my questions:

- Any way I can register my printer with Canon and get support? I mean, I know it's been almost 3 years...

- Any way to retrieve or reset the admin codes?

- Any way to update the firmware without the admin codes?

Thanks!

Re: MF644Cdw bought from Amazon (sold by Amazon) can't register, S/N rejected

rs-eos — Mon, 09 Mar 2026 18:49:15 GMT

You should call up support directly: 1-800-652-2666

Regarding Amazon, I wouldn't trust them going forward. Always best to purchase from a dedicated authorized Canon dealer or directly from Canon.

Re: MF644Cdw bought from Amazon (sold by Amazon) can't register, S/N rejected

shadowsports — Mon, 09 Mar 2026 19:22:02 GMT

Greetings,

I'm with my 644 now. Mine is one numeric digit, two alpha and five numeric.

My 656 is 3 alpha and five numeric.

If your printer has internet connectivity you should be able to update the firmware from the printers LCD . Just scroll to the right and you'll see an icon, update firmware. When you tap the icon it takes about 3 minutes. Don't touch any keys and don't send any jobs to the printer.

If you have set a system manager pin and don't remember it you'll need to contact Canon support.