JRC JMR-92 Series Field Service Manual page 639

Step 4 Check operation.
After the replacement of the operation circuit B is completed, turn ON the circuit breaker for the
power supply of the display unit and check the operation as follows.
(1) Check that a keyboard open error has not occurred.
(2) By referring to "7.2.3 Checking the Operation of the Operation Unit [Key Test]," check
that all the buttons and knobs of the KOPU respond normally.
(3) By referring to "7.2.5 Testing LED Brightness [Light Test]," check the brightness of the
LEDs.
This completes the replacement of the operation circuit B.
Chapter 4 Replacement procedure 4-418