Casio CTK-591 Service Manual page 12

9. Remove 28 screws and then the PCB ASSY (CN1M).
Note: Fix the LED (D4, D5, D50, D53, D54) to the PCB according to the height as shown in the figure below while
paying attention to the polarity.
Refer to the illustration on the PCB for the details of the polarity.
D53 D5
D52 D4
D54
D50
8.7 ± 0.5 mm
D50, D52, D53
— 11 —
Anode
Cathode
D4, D54
D5
D4,D54: 11.0 ± 0.5
D5: 11.5 ± 0.5