HP Designjet 250c Service Manual - Page 161

EEROM Errors What is an EEROM error? An EEROM error means that some of the internal tests that the firmware performs have detected that, when reĆreading information from the EEROM, it doesn't correspond to the information that had previously been written there, or that the checksum of all the information is incorrect. This failure has five possible causes: D Faulty electronics module. D Contact problems with the trailingĆcable connections. D Faulty trailing cable. D Faulty carriage. D The plotter was turned off while a test was writing to the EEROM, thus leaving corrupt information (or a communication cable was disconnected while sending information to the EEROM using software diagnostic tools). It is generally not easy to discover the cause, due to the intermittent character of the failure modes. If you are sure that the failure occurred just after an electricity powerĆcut, or after turning off the plotter during the bench run or other service tests, then the plotter 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 plotter: If it is easy to reproduce a Steady 135 error, then try one or all of the following steps for a possible solution: 330 350C 1 Configure the EEROM with the correct model ID (instructions ' page 8Ć28). 2 Ensure that the trailing cable is properly connected at both ends. 3 Connect a new trailing cable outside the plotter to the carriage and electronics module (without installing the cable completely). If the error disappears, install the new trailing cable. 4 Connect a new carriage outside the plotter to the trailing cable, and switch on the plotter. If the error disappears, install the new carriage. 5 Change the electronics module. D There is sometimes an EEROM error when you switch on the plotter (normally shows up as a Steady 135 error): 1 Switch on the plotter, allow it to initialize until it has completed the powerĆon LED sequence, and switch off the plotter. (You are now sure that the EEROM has not been corrupted. If a Steady 135 error appeared, it also corrects the EEROM contents, and the next time you switch the plotter 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 135 error appears during the initialization sequence, and the carriage does not begin to move, then the EEROM is probably faulty. Change the electronics module. C4699Ć90000 Troubleshooting 8Ć27