Casio CTK-591 Service Manual

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3) Equipment connection/Procedure
Vop voltage setting
Watching the LCD at a 34.9° angle to the horizontal, adjust Vop
voltage so that unenergized segments are seen dimly.
ADJUSTMENT
DISPLAY PCB
1) Items to be adjusted:
2) Adjustment and Test Point Locations
(TOP VIEW)
Input
Connection
Input
Point
Input
Signal
Adjust
Output
Connection
Output
Point
Adjust for
VR1
Voltmeter VLCD-
VD5
Adjust for 4.2 ~ 4.3 V reading
on voltmeter under the tem-
perature 20 ~ 25 °C.
Make fine adjustment accord-
ing to the next instruction.
Output
Set Voltmeter
VLCD
VD5
34.9°
LCD
Eye
Item Measuring Instrument
Vop voltage setting Voltmeter
VLCD
VD5
30 pin
33 pin

Casio CTK-591 Specifications

General

Number of Keys	61
Rhythms	100
MIDI	Yes
Power Supply	9V DC
Keyboard	Standard
Display	LCD
Polyphony	12 notes
Terminals	MIDI
Effects	Reverb
Auto Accompaniment	CAS (Casio Auto-Accompaniment System)