hello! i'm currently having issues with a sharp mx3100 distorting and sometimes blanking the black toner in both color and monochrome modes. it's an intermittent issue that seems to pop up after 100 copies are ran after the machine is powered off. i have updated firmware, tested the hv board with sim 44-06 (checked ok), tested the shutter solenoids, recalibrated, replaced the drum unit, dv unit, and laser unit, and even put a different primary belt unit just in case. when i run a 64-4, a 64-1, a 64-2, and a 61-4, i either get a good print out, or it's distorted only on the black toner, or sometimes the black toner doesn't show up at all. the wall voltage and line conditioner have been checked out ok, so i dont think its an external voltage issue. the only other thing i can try is replacing boards one by one. has anyone else had this problem? any ideas will be very much appreciated!