trying to start IBM Personal Pageprinter (not working)

[monoxrom]

Hello All!
This forum is my last chance to start IBM personal PagePrinter from 1988 year

This is laser printer and main model is IBM 4216 010, he starting up but have error code "781" and working diode "prufen"

http://i.piccy.info/i9/4e416ed9cf37d94dfac6bf330c974ec4/1533204905/321876/1260581/4216.jpg

I can't find any documents for this model Anybody have them? Or maybe anybody know what this error mean?
Maybe on another IBM printers error codes the same?

One time i have error 071 this is mean "replace cleaning unit"
http://i.piccy.info/i9/1d6b7556be6355e14ef8161e5ced3d97/1533312888/343467/1260581/4216_2.jpg
But no error code 781 on this "help secret door"

 

[ardent-blue]

Try comp.sys.ibm.ps2.hardware

 

[monoxrom]

I need to know what is error 781 ((((

On this few weeks i found that:
http://i.piccy.info/i9/08b3576dce12babbba2fd830463b1186/1535365059/787102/1265861/main.jpg

On this engine board present NEC 7811 controller, if i remove them prineter starting normal! no error 781 but printer not printing
Also i was insert NEC 7810 controller or total remove engine board and all was "ok" No error codes but printer no printing

Now i think i have problems with my NEC 7811 controller, this chip have internal firmware and this can be damaged ((((
Or maybe something another is wrong but i need to know what is error code 781