HP 4250n Toner Issue

[Big Al]

This printer has about 200K pages on it. I replaced the swing plate assy. and the gear on the fuser. This proceedure went well thanks to the Printer Techs instruction set. The printer now feeds paper very well. The test cartridge they gave me was a refill and it was putting extra toner on the page. The first page will always have a band of extra toner on top of the normal header for the page about an inch and a half long. After a few more pages to work out all the extra toner the rest of the job will print fine. Much to my chagrin the brand new HP toner cartridge does the same thing. It is only the first page printed that does this. When I start up the next job I always get the same result. The customer does not have a spare printer that I could use to try swapping some parts. This is not part of the normal inventory of printers that I work on so my resources are limited. Help me Obi Wan Kenobi, you are my only hope.
Al

[redcow]

Obviously, it's the new "swing plate". Put the old one back in, and see if the heavy toner goes away!!!


Start with the EASY...xfer roller
Next....DC Controller
Next....Hi Voltage which brings the voltage to the transfer roller and drum

[Big Al]

Ckustomer does not have a parts machine to swap parts with so their decision is that this one will become their parts machine!
Thanks!
Al

[cs_steve]

Ckustomer does not have a parts machine to swap parts with so their decision is that this one will become their parts machine!
Thanks!
Al

Just for future reference, the high voltage & low voltage are 1 unit (power supply assembly). Replacing that power supply normally fixes the problem you described, we're seeing it more and more often where a band of toner appears at the top and stretches the entire width of the page, even past the normal borders.

[Big Al]

Thanks Steve! I thought that was the case but did not have a donor machine to use for parts.

Al