mf731cdw is printing black as grey

[HBSammy]

mf731cdw is printing black as grey even after "adjusting gradation" the image printed during the adjustment is fine re: colors but the black is NOT black but grey. Running off a Mac. This is new, we haven't changed anything. It just started not printing a deep black. Yes the cartridge has 80% fill.

[Hector]

Hello HBsammy,

The issue could be caused by a problem with the toner cartridge, the settings or the driver being used. We would be happy to assist with the issue. To provide some feedback or some troubleshooting steps, we would need some additional information. If you could reply to this message with the information below, we can provide some assistance. For a more immediate resolution, you can contact support over the phone at 1-800-652-2666.

1. What version of the Mac operating system are you using on your computer and what program are you printing from?
2. Do you run into the same issue when you make black and white copies from the glass?