59.10 error code

[Portasky]

My printer showed 51.10 error code. I tried to follow the direction ( power Turn off the printer and turn on ) . But the error still appear. How should I do ? Thanks

[ALS-77]

Well, you've listed two different error codes: 59.10 & 51.10. 

59.10 is a main drive error, which could be a bound up fuser.

51.10 is a laser error, which could be a bad laser unit.

Which error do you have?

[Portasky]

I am sorry it shows 51.10 error

[ALS-77]

See if the printer will print an engine test page. There is a small hole on the right side of the printer you use to activate it. Here's a web link showing how:
https://www.fortwayneprinterrepair.com/wordpress/2012/06/26/hp-laserjet-4250-4350-engine-test/

If the printer can print an engine test, then you may have a bad formatter. If it does not print, then you probably have a bad laser unit.