The Grey Ghost - HP LaserJet 4+

Greetings,

Symptoms:

1) The lower the Density setting, the more grey the page.
2) Dark grey band approx. 3.5" from top of page
3) Ghost or white-shadow printing

I've searched this forum and others for the symptoms I have and the closest causes I've found are either a bad wiper in the toner cartridge or a failing High Voltage Power Supply.

The symptoms began after I opened the machine to replace the rollers to cure the "accordian jam" problem. While I was in there I removed 20 years of dust, replaced the transfer roller, and replaced the eccentric paper tray pick up roller.

I tried replacing the old toner cartridge with a new genuine HP toner cartridge. The symptoms are identical.

Most recently I cleaned all the contacts I could find on the HVPS itself, the printer chassis, and the toner cartridge.

Since pictures speak a thousand words:

Engine Test (Density = 3)
https://picasaweb.google.com/lh/photo/z7lYpffUQoriWAKl9Rzp7F4HEjtZWTkG 6bxguE6fs7w?feat=directlink

PCL Demo Test Page (Density = 3)
https://picasaweb.google.com/lh/photo/Wp71v5jAczJXLoVA1ppXd14HEjtZWTkG 6bxguE6fs7w?feat=directlink

Thanks in advance for your help,
Paul