Lexmark Optra T Service Manual - Page 134

4069-XXX FRU 4 Smart Cartridge Cable Engine Board Action Check the voltage on the smart cartridge contact. The voltage measures approximately +5 V dc when not writing data to the engine board. If data is being written, the voltage measures approximately +12 V dc. If incorrect, disconnect the cable from J21 on the engine board and check the voltage on J21-1. The voltage measures approximately +5 V dc. If incorrect, replace the engine board. If correct, replace the smart cartridge cable. Serial Port Service Check Run the "Serial Wrap Test" on page 3-12. Note: The Serial Wrap Test is designed to check the serial port hardware by using a wrap plug (P/N 1329048) and invoking the Serial Post Diagnostic Test. The test helps isolate the printer from the serial cable and host. The test provides failure information on the display for approximately three seconds. If the test indicates a problem, replace the controller board. Toner Sensor Service Check Service Tip: Check the print darkness MENU setting before checking the toner sensor. This service check is intended to be used when a 929 Service Error displays. FRU 1 Developer Drive Assembly Action Incorrect operation of the developer drive assembly can cause the printer to display a 929 error code (Toner Sensor). Check the developer drive assembly for correct installation, any sign of worn, loose or broken parts. 2-106 Service Manual