HP 450c Service Manual - Page 19

If you are sure that the failure occurred just after an electricity powerĆcut, or after turning off the Printer during the bench run or other service tests, then the Printer is not faulty. You just need to reset the EEROM. In other cases, you need to find the cause: D There is always an EEROM error when you switch on the Printer: D If it is easy to reproduce a Steady EKL error, then try one or all of the following steps for a possible solution: 1 Configure the EEROM with the correct model ID (instructions ' page 4Ć27). 2 If you cannot configure the EEROM with the correct model ID after several attempts and you continue getting the same error code, replace the electronics module ' page 8Ć13. D There is sometimes an EEROM error when you switch on the Printer (normally shows up as a Steady EK error): 1 Switch on the Printer, allow it to initialize until it has completed the powerĆon LED sequence, and switch off the Printer. (You are now sure that the EEROM has not been corrupted. If a Steady EK error appeared, it also corrects the EEROM contents, and the next time you switch the Printer ON, the error should not occur in good units.) 2 Leave the unit off for 15 minutes to detect if the EEROM is losing its information. Then turn it on again and allow it to initialize. If a Steady EK error appears during the initialization sequence, and the carriage does not begin to move, then the EEROM is probably faulty. Replace the electronics module. Troubleshooting HP DesignJet 430, 450C and 455CA Printers 1-9