Question Brother Printer - uneven print

[THRobinson]

I see posts and vids about streaks, blotches or loose toner, but not finding anything about uneven printing, or banding.

Basically if I printed a full sheet of 100% black, you can see it go from black to grey and back again like a wave.

Cleaned the roller with isopropyl alcohol, cleaned the wire with that slider thing, shook the cartridge... Same thing.

What else is it? Cartridge just old?

 

[kerberos_20]

1.Light Print (partial).​

1. Gently shake and reinstall print cartridge(s), making sure the cover is closed securely. If this helps, the cartridge is close to being empty, and will need replacement soon.
2. If light areas are strips in the direction of paper movement (as in the picture), laser/scanner optics may be partially dirty. If one side of the page is light, check mechanical alignment between cartridge(s), drum(s) (if separate from cartridge), and transfer elements. This can also indicate high voltage problems (see next step).
3. If light areas are randomly positioned on page, check high voltage contacts to the cartridge(s), drum(s), and transfer elements.
4. If contacts look good, the high voltage power supply may be bad. Inspect the surfaces of imaging elements (cartridge(s), transfer roller or belt, etc. – and even the fuser) for visible defects corresponding to the light area on the page.

 

[THRobinson]

1.Light Print (partial).​

1. Gently shake and reinstall print cartridge(s), making sure the cover is closed securely. If this helps, the cartridge is close to being empty, and will need replacement soon.
2. If light areas are strips in the direction of paper movement (as in the picture), laser/scanner optics may be partially dirty. If one side of the page is light, check mechanical alignment between cartridge(s), drum(s) (if separate from cartridge), and transfer elements. This can also indicate high voltage problems (see next step).
3. If light areas are randomly positioned on page, check high voltage contacts to the cartridge(s), drum(s), and transfer elements.
4. If contacts look good, the high voltage power supply may be bad. Inspect the surfaces of imaging elements (cartridge(s), transfer roller or belt, etc. – and even the fuser) for visible defects corresponding to the light area on the page.

I don't see a picture, though suspect this is a cut'n'paste from another source.