Brother 8860DN repeating smudge in left margin

[LightGuy48]

I have an older Brother 8860 that has been a very reliable MFC until recently. It has a very severe dark repeating smudges covering the left 1" side of the page.

I have replaced the toner cartridge, the image drum, and the fuser. I found the left side of the fuser had some wrinkles in the drum material. I have also cleaned all of the electrical contacts for the drum/toner module. They all appear to be in good condition, they are not dirty or burned.

Due to the way the smudging is it's difficult to get an exact measurement on it but some of the patterns do seem to be around 3.75" or 95.25mm which is fairly close to the imaging drum, however, two different imaging drums both have the same issue.

I've attached a scan of the issue. I'm completely out of ideas short of replacing the HV power supply

 

[LightGuy48]

I performed some additional troubleshooting on the printer tonight and entered the maintenance mode on the unit and printed a test / pattern page for the unit which has various patterns, blocks, shading, grids, etc. toward the bottom 1/3 of the page it prints a solid black bar. I noticed when examining the paper I literally found thick blotches of toner on that solid black bar and after that bar the paper remained white without the typical residual toner smudges.

However, on the next page print the smudges return to the left margin again. Does this indicate potentially a bad toner cartridge or maybe a bad developer drum? Maybe the nipping blade is not clearing excess toner off the developer drum?

Although when I examine the developer drum I don't see excessive mounts of toner on one end of the drum.