Printer Hardware Factory Reset Without Admin Password

[JaroSR]

Hello,

We have got two HP Printers with changed admin password. We do not know what the password is and the person responsible for the password change has been gone for over two years now and there is no way of contact. We never really needed to go into the printer options until now as changes have been done on the network and I need to add new entry into access list but its blocked by admin password which is understandable. 

I am looking for a way to restore the printers to factory settings. Printer models:

1x M454dw
1x M426fdn

I have read the manuals. I have looked through the solutions on here, youtube, google and I am still unable to find anything that would help me with our issue. 

[BeemerBiker · Accepted solution]

There is a secret to this as explained here

https://h30434.www3.hp.com/t5/Printers-Archive-Read-Only/Reset-M426fdw/td-p/5529395

let me know if it still works as new firmware may change the secret reset

Secret factor reset: Hold down to the right of the ? while unplugging and then powering on


Full feature software 426
https://ftp.hp.com/pub/softlib/software13/COL61843/ma-149276-10/HP_LJ_Pro_MFP_M426-M427-PCL_6_v3_Win...


Full feature software 454
https://ftp.hp.com/pub/softlib/software13/printers/LJ/M453-M454/Full_Webpack-48.6.4642-CLJM453-M454_...

Wi-Fi setup using smartphone
https://www.youtube.com/watch?v=PwM7ojvt27I

[JaroSR]

Hello,

Thank you, worked perfectly for 454 and 426