Download This Bulletin provides specific troubleshooting information for the Digital Dash (Z31) Power Unit (Part Number 24821-01P11) in cases where a customer complains of the following: ^ ^ ^ Digital display flickers (intermittently, on and off). Digital display does not operate. Fuel level/trip odometer/distance-to-empty intermittent or inoperative. Follow Test Procedure, “Power Unit Check,” found on Pg. E1-77 of the 1986 300 ZX Service Manual: A. If measured voltage or continuity is not correct, the Power Unit is faulty and must be repaired/replaced. Note: In cases where intermittent display operation is experienced, the voltage or continuity checks may, falsely, appear OK. B. In most cases, the failure of the Power Unit is caused by cold solder or cracked solder at the joint formed between the pin connectors and the printed circuit board foil. The following may be used to repair those units which have defective soldered joints: 1. Remove Power Unit from vehicle. 2. Remove the seven (7) screws which hold the assembly together. Note location of “Star Washer” prior to disassembly. 3. Locate the 28 Pin Connector Socket which protrudes through the bottom side of the printed circuit board.