I've been working on Samsung for over two years, and this is the first one that needed a drum replacement. It turns out that the drum times out at 24K clicks, 4 clicks per color, 1 click per B&W.
So my customer buys a drum unit, reads the directions, and installs the Imaging Unit. So far so good ... except for the fact that the "Replace Imaging Unit" message is still there.
Two hours of searching to find this in the Service Manual:
Press: Menu, #1934, Menu, "Tech Mode <Tech Mode>" OK, "Data Setup" OK, > x7 to "Clear Counts" OK, "Enter Password [????]", 1934, OK, "Clear Counts [Total Page CNT]", >x3 to "[Imaging Unit]" OK, "Clearing ", back.
It just doesn't make any sense to me for the manufacturer to sell an imaging unit as a user replaceable supply, but does not include the reset procedure with the drum unit, or in the users manual. And the procedure in the service manual is nearly incomprehensible.
Maybe this will save someone two hours of searching. =^..^=