Lexmark Optra T Service Manual - Page 61

4069-XXX FRU 3 +5 V dc at any Option Connector 4 +5 V dc at the controller board test point 5 +5 V dc at the engine board Test Point 6 LVPS Fuse F1 7 LVPS Fuse F1 - Continues to blow after LVPS installed in the printer. 8 LVPS Action Check for +5 V dc on any of the option connectors. The easiest to access is the envelope feeder connector located behind the lower front door. If +5 V dc is present at any of the connectors, go to step 9. If +5 V dc is not present, go to step 4. Check for +5 V dc at the +5 V dc test pad located on the controller board. If correct, go to step 9. Check for +5 V dc at the +5 V dc test point on the engine board. If correct, replace the engine board. If incorrect, go to step 6. Remove the LVPS from the printer and check fuse F1. Replace the fuse if the fuse is blown. Replace fuse F1 if necessary. Turn the LVPS on/off switch Off and connect the AC line cord and turn the LVPS On. CAUTION: Before checking fuse F1 turn the LVPS Off and disconnect the AC line cord. Check fuse F1. If the fuse is blown, replace the LVPS. Remove the LVPS from the machine. CAUTION: Before making any measurements on the LVPS output connector, observe all necessary safety precautions before applying AC power. Measure the voltage on LVPS output connector CN3. The voltage measures +5 V dc. If incorrect, replace the LVPS. Diagnostic Information 2-33