25 V Circuit; Voltage Line - Casio A-10 Operation, Service Manual & Parts List

25 V Circuit

DC-DC converter RN5RY202 (U23) generates +25 V and it makes up 25 V system for LCD.
V25LCD : +25 V source for LCD.
VOL : Connect to Contrast Dial on Z305-LD PCB.
PLCDB : Controls ON/OFF of V25LCD. From pin 167 of SYSTEM LSI.
V3SYS : +3.3 V source.
V3 Circuit
3.77 V
Q31

Voltage Line

U1 U3
HD6417096 MB87A908
CPU SYSTEM
V3SYS
V3ROM
V3RAM
V3AUD
V3IRDA
V5SYS
V5CARD
V25LCD
U4 J10
MBCG25942
3 V 5 V 3P Jack
Q30
V3SYS
Q32
Q17
PLCDB
Memory Slot
U301
32M-MASK
ROM
Connector U601
LA5312V
PCMCIA LCD D/D
D10
VDD VOUT
U23
EXT
DC/DC
Converter
(Generates 25 V)
U7/U8
UPD42S16160
D-RAM
D601/602
LCD
LED
— 37 —
V25LCD (To LCD)
(25 V)
Contrast
VOL
U6 U5 U18
MAX3241 MC34119 TFDS3000
RS232 C Audio IC IRIC
Q3 ~ Q7
Touch Panel
Dial