2420DN Printing Light on one side

[SVenice]

I have a couple of HP 2420DN Printers where they are printing very light on the left side of the page, to the point it's invisible.
I've tried the following:

Replaced the Fuser and Toner kit from a unit that is working.
Did a cold reset.
Ran a 1/2 page test and the image is on the drum, even though it's not on the page.
Replaced the foam transfer roller with a new one.

None of these have helped.

Any suggestions or ideas.

Thanks,

Steve

[Big Al]

We have several hundred of these and when we had this problem it turned out to be the laser scanner assembly. Others have reported toner contamination on the plastic corrective lenses that the laser beam shines through on its way to the toner cartridge. I have never seen this but it certainly is possible. My guess would be the laser. I cannot explain why only one side of the image but changing the laser assy. fixed it. It is easy enough to swap. The formatter drives the laser scanner so if it is not the laser try the formatter. Please let us know what you find.

Al

[SVenice]

Al,

Thanks! I was able to find a service manual online and easily got to the laser scanner assembly. I took it out and the mirror was a mess (dark film on it). I cleaned it with Isopopil (I read not to use liquids, but this stuff was on good), and put it back together.
Print looks good. Not great like brand new, but I cleaned it twice and increased some of the printing quality settings and it's more than readable.
Now I know what to do with the rest of my 2420's.
Thanks for the kick in the right direction.

Steve