4100 prints one blank and then one black

[JJprinter]

Hi,

I have a customer who has one page printing a blank one and then if you turn the printer off and back on again it will print all black.
Sometimes it will print a few blank ones then a black will appear.
There are no errors being displayed in display.
They have had 3 techs check it out and they can't find the problem.

[JeffH]

Can you run down the things that you are positive that have already been tried?

[JJprinter]

They apparently checked all power issues/ controller/power supply/ main board and so on
Changed the cartridge twice
checked cables
checked computer program
checked ram
paper type

All above apparently working or correct for this printer
We still have not found a solution
Hope you can help Jeff
Thanx

[JeffH]

Ok.. lets run down what it could be...

High Voltage power supply
Engine Controller Board
Toner
Formatter PCA
Laser scanner and cable
Drum ground spring


I think I got them all.

It sounds like something is turning the laser on and off. Could be the cable between the laser and engine controller. What happens when you do an engine test? Was something done to this printer before it started happening or did it just start happening during normal use?

When doing a half self test, does anything get on the drum of the cartridge?

I'm not one to rely upon what the other techs found at this point. I would check things in this order yourself so you are sure...

High Voltage Power Supply and all connections including the springs at the toner cartridge.

Engine Controller board and connections.

Laser scanner and cable.

Formattter PCA.


Do you have a working unit there you can use as a test unit?

Jeff

[JJprinter]

Well Jeff it was the formatter PCA it was actually working and printing but would short out off and on creating numerous weird print outs. Blank then black then blank.
The only strange thing that is still a mystery, why the panel did not indicate an error message, even a #50 or something. You think it would give some error at one point or another.
All fixed now.
This is one my techs will not forget.HaHa
Thanks for your reply
Have a good one.