LG KE590 Service Manual page 49

4. TROUBLE SHOOTING
4.2.1.1 Regulator Circuit
U406
TP1
C437
U405
TP2 C435
C435(C437)
LGE Internal Use Only
Regulator
C435(C437) 2.8V?
NO
Check U101
VBAT
TPS79928DRVR
C433
0.1u
REGEN
TPS79928DRVR
<Fig.1> Regulator Circuit Diagram
Copyright © 2007 LG Electronics. Inc. All right reserved.
- 50 -
YES
Regulator is
OK.
TP1
LDO Supplies
U405
6 1
IN OUT
5 2
NC NR
4 3
EN GND
7
PGND C434 C435
0.01u 2.2u
TP2
U406
6 1
IN OUT
5 2
NC NR
4 3
EN GND
7
PGND C436 C437
0.01u 2.2u
Only for training and service purposes
VCC_SYN
C_VCCRF