I've mostly found that issue to be caused by a toner .
Do the disable toner test again ..to see where the problem is...Since you probably had to do some disassembly to fix the contact issue, though you could have caused this problem..
Does the printer see both of these toners as true HP Toners ? If not, I've had cases where the printer has trouble Calibrating .. if so, nothing to do but get another toner..