Error message about imaging unit

[GeoffCr]

Samsung Xpress SL-M2885FW Laser Multifunction printer. A message (and flashing light) tells me to 'Replace with new imaging unit.' But an imaging unit is meant to last for c. 50k pages and I've used only 4 laser cartridges = c. 12k. I therefore assume that the problem is not the imaging unit but an incorrect error message. Is that likely to be the case? And, if so, how do I override the error message?

[Valsimot]

The drum can print 9k pages, not 50k. 

https://www.hp.com/us-en/shop/pdp/samsung-mlt-r116-imaging-unit 

[GeoffCr]

Thanks. I'd clearly misread something about 50k. At 9k that means that the computer consumables are much more expensive than I'd expected. The last decade has seen a trend to cheap printers and expensive consumables. It's a viable business model, I suppose. A bit like razors....