Service Manual 2-5the configuration card, and does not change. Ethernet address is stored only on theconfiguration card, and cannot be rewritten. The ethernet address is not written to theNVRAM chip.Personality parameters are a subset of network configuration parameters which arepopulated to the configuration card over time, as the printer is configured by thecustomer. The personality parameters are copied, or “shadowed”, from the mainboard's NVRAM chip to the configuration card during the normal operation of theprinter. When the configuration card is inserted into a new printer, the personalityparameters on the configuration card are written into the NVRAM chip of the newprinter. When a printer is powered on, if it contains the configuration card of anotherprinter, the personality parameters are automatically copied to the NVRAM chip. Ifthe configuration card is removed, the printer will reboot as a B (non-networking)model configuration. Refer to the “Configuration Card Personality Parameters”section at the end of this chapter for a detailed list of “shadowed” personalityparameters.Power Control BoardThe power control board distributes drive voltages to operate the printer’s variousmotors, solenoids and clutches. The power control board also provides the interfacethat returns information from the printer's sensors to the main board. The sensors areused to track mechanical and thermal functions, such as the position and temperatureof the printhead. The power control board also generates regulated +/- 12 volt (V) and5 V from unregulated +/-15 V power.Power SupplyThere are no field adjustments necessary on the power supply. In general, the powersupply has two main, yet interrelated sections: the AC section and the DC section. Inthe AC section, power is routed to 10 triacs which, under main board logic control,supply AC power to the 10 heaters in the printer.Two fuses provide current protection to the triacs. Fuse F2 and F3 protect the powersupply from, most often, a shorted triac caused by a defective heater. If the F2 or F3fuses blow, it is best to replace the electronics module (and, of course, the defectiveheater), rather than the fuse. Otherwise uncontrolled, with the fuse replaced but thetriac shorted, AC power may be applied to the heater. Each time the main board turnson a triac to activate a heater, it is turned on for only a fraction of a second. The mainboard must constantly readdress each heater it wants to remain on. This means if theprint engine firmware should fail, the heaters automatically shut off.The printer is also protected by thermal fuses. A thermal fuse opens in the unlikelyevent of a “runaway” heater following a hardware failure. The drum and the paperpreheater thermal fuses are located on the paper preheater. Additional thermal fusesare located on the printhead and on the ink melting elements.
