Post charger HV module assemblies The post charger HV module assemblies are located on the mid- upper of the rear of the printer. Shown in figure 139 below are the assemblies in an HP Color LaserJet 8550 printer. Compare the developer/imaging drum bias supply to the same part from an HP Color LaserJet 8500 printer, in figure 140 on page 289, callouts 1 (the smaller portion) and 2 (the larger portion). The smaller portion is combined with the larger portion in HP Color LaserJet 8550 printer models, and so is not present in these models. Figure 139. Developer/imaging drum bias supply, HP Color LaserJet 8550 printer 288 Chapter 6 - Removal and replacement EN