ok il start by saying that my english is veryyyy bad.
ok so the developer is guarantied for 80000 copies but i seen 200k with a new dev. (developer type dv310) after some of the developer is lost in the copying proses the ac-dc sensor detects that the concentration is rong and it shows the C2557 error thats wen the error is shown by the copier .
solving it is simple you can replace the dev. and run F8 mode if it dosent work manually ajust the acdc to a lower value (lower value means that is les tonner in the dev. hyer value more tonner obviously ) , 0r leave the old dev. in it and ajut the acdc to about 180 (you can ajust to 180 take out the tonner botle make some black copies(30) and put back the tonner bottle and adjust to a lower value that works) .
The problem can also apear if the copier docent supply tonner so check that first .
Entering the service menu is simple pres utility > (toch screen) original size> (kepad) stop>0>0>stop>0>1 the password from the manufacturer is 00000000 , in the service menu select tech mode in ther yowl find the different start modes F8,F... ,
and you have printer select printer and acdc adjustment ,
pres C to clear the value and via keypad enter the desired value .
THE REST IS UP TU YOU MY FRIEND . CAUTION IF YOU DONT HAVE ANY IDEA ABOUT A LASER COPIER DONT
EVEN ENTER THE SERVICE MODE CAUSE YOU CAN DO MENY WRONGS IN THE COPIER . GOOD LUCK