3 - 82 Phaser 840/850/860/8200 Color Printer - Service ManualInspecting the power supply fusesThree fuses (F1 - F3) are mounted on the power supply.1. Turn off the printer and remove the power cord.2. Remove side and rear covers.3. Remove the screws securing the power supply.4. Disconnect the wiring harnesses plugged into the right side of the power supply andremove power supply.5. With a DMM, determine that the fuses on the power supply are functional. Measure theresistance of all fuses to LINE as indicated on the power supplyís shield.If any fuse opens, the power supply does not function and should be replaced.Caution Fuses F2 and F3 are used for the AC heaters within the printer;they protect the power supply from, most often, a shorted triac. IfF2 or F3 blows, replace the power supply rather than the fuse.Otherwise, with the fuse replaced, but the triac shorted, AC powermay be applied to the heater without the printer even being turnedon, resulting in a thermal runaway condition.If the fuses are functional, but the printer's power supply does not output DC voltages,proceed to the topic, "Testing for shorted drivers" on page 3-83. Also refer to SF157.Fuse F1 is for the DC power supply, all DC outputs.Fuse F2 is for the following heaters: H3 Jet Stack Left H4 Paper PreHeat H10 Jet Stack Right H11 Reservoir #2 H12 Drum #2 H14 Reservoir #4Fuse F3 is for the following heaters: H1 Drum #1 H2 Reservoir #1 H5 Black Ink Melt H6 Magenta Ink Melt H7 Cyan Ink Melt H8 Yellow Ink Melt H9 Cap Wipe Heat H13 Reservoir #3
