Hello.
We try change developer 5 times (312GV), main charger 2 times (310NC), charge roller(NROLR0195QSZZ), OPC(312GR), blade(311BL), pressure roller(311LH), but the toner density value change randomly 130 between 80 and the developer coming out.
Now the machine is dead because every printing job is jam or stop by error code.
Thanks for helping!