All of a sudden prints have a light but noticeable pink background. I didn't change any settings. Help!

Is your magenta drum near the end of its life? If you run beyond 200% of yeild I've had the old drums start laying down a background like this.

Could be, have been running it for a long time. Is there a way to check without buying a new one?

Go into service mode, click Copier, click Miscellaneous or Misc, and you will see the drum life displayed for each drum. There's also an option to show bars on the normal display but these aren't very accurate and won't tell you anything beyond 100% yield (just show zero bar) Be very very careful and don't press anything you don't understand in service mode or you can destroy your machine.

If you haven't already, make sure you run a Full gradation adjustment - click the additional functions on the keypad, Adjustments - Full Graduation Adjustment. (don't mean this as an insult if you already know this, just don't know how long you've been using the machine for.)

Where do you go into service mode?

To enter service mode, Hit the * key. Then press and hold 2 and 8 together for 10 seconds. Then hit the * key again quickly and you will see the display change to service mode. (to exit, hit the reset key.)

Shows 370% for magenta!

Does anyone rebuild these GPR11 drums?

I do not know of anyone currently rebuilding GPR-11 Drums as no parts are available. And with that much use on it, probably wouldn't be worth it for this drum.

Note that the new drums will have small blue dot stickers on the outside of the brown box and on the drum itself and address background issues. Also System Software Ver. 85.02 includes fixes for background issues if you encounter this on an ongoing basis with more than just this one drum. In this case however, I believe you simply have a drum that has served a long, long life and is ready for retirement.

I just replaced mine today for that same reason.
It was only at 95% life when it started the pink treatment.
Thank god for maintenance contracts!

Definltely glad we have a service contract!

We most often get up into the 150+% range before drums start dropping toner all over (and then once they background within 500 prints they usually start undulating color and then die entirely with no color from that drum) but we did just lose a magenta at 109% last week. I'm not quite sure where the yeild % comes from; one tech said rotational count is the major factor which seemed reasonable, except that after 150 they seem to sometimes jump so you'll all of a sudden see a readout of 350% within 1000 prints...