Lexmark T522 Service Manual - Page 107

4520-xxx Operator Panel Service Check Operator Panel Buttons Service Check Note: Before continuing with this service check do the "Button Test" on page 3-11 in the diagnostic aids chapter. FRU 1 Operator Panel Assembly 2 Engine Board (No buttons work) Action If any button fails the Button Test, replace the operator panel assembly. Check the voltage at J11-5. The voltage measures approximately +5 V dc with the controller board removed. If incorrect, replace the engine board. If correct, check the continuity of the operator panel cable. If incorrect, replace the cable. If correct, replace the operator panel assembly. Operator Panel Display Service Check Service Tip: The printer has detected a problem with the engine board, operator panel cable or operator panel assembly if POST does not complete and the printer emits 5 beeps and stops in a continuous pattern until the printer is turned off. The operator panel cable is an individual cable on some printers and a combination cable assembly with the cover switch cable on later models. Note: If the operator panel is operating properly except for a Pel or a few Pels missing or broken, run the "LCD Test" on page 3-11 from the hardware tests before continuing with this diagnostic service check. Diagnostic Information 2-79