Sharp GX15 Service Manual page 62

GX15
11. The display does not appear on Display.
Is Display unit fully inserted to CN102?
Clean the contact point of CN102 and insert the unit again.
Does the display appear?
Replace Display.
Does the display appear?
Is 3.6 or more voltage applied to VBAT terminal
(IC110 pin 4) ?
Is 2.93 + 0.37, – 0.53 V applied to VDC terminal (CN102 pin
15 to VEXT)?
Is 3.0 ± 0.1 V or more applied to VCC2 terminal (CN102 pin
14 to IC110 pin 3)?
Is voltage on VDD2 terminal (C194) boosted to approx. 6 V?
Is the voltage approx. -10 V on VSS2 terminal (C200) and
approx. 15 V on VDD1 terminal (C211)? Are capacitors C209,
C210, C217, C218, C200, and C211 in good appearance and
mounted properly?
Is approx. 3 V applied to LCD reset (R178)? Is R178 in good
appearance and mounted properly?
Are C216, C218, C221, C222, C223, C227, R157, R176,
R186, R197, R142, R151, R152, and R154 good in appear-
ance and mounted properly?
Display unit is defective, or connector CN102 is mounted
improperly.
CONFIDENTIAL
YES
YES
NO
YES
YES
YES
YES
YES
YES
YES
Improperly inserted to the connector.
NO
The contact point of the connector is dirty.
NO
Display unit is defective.
YES
Go to the section "Power dose not turn on." (see page 2-44)
NO
Go to the section "Power dose not turn on." (see page 2-44)
Is short terminal (between CN102 pin 15 and VEXT) defec-
NO
tive?
Short terminal is defective.
Regulator IC110 is mounted improperly or short terminal is
soldered improperly.
Are IC110 and short terminal (between IC110 pin 3 and
NO
CN102 pin 14) good in appearance and mounted properly?
Regulator IC110 is defective.
Capacitors C215 (between C1+ and C1-) and C212/C194
(between C2+ and C2-) are defective or mounted improperly.
Are capacitors C215 (between C1+ and C1-) and C212/C194
NO
(between C2+ and C2-) in good appearance and mounted
properly?
Display unit is defective.
Capacitors C209, C210, C217, C218, C200, and C211 are
NO defective or mounted improperly.
R178 is defective or mounted improperly. Otherwise the digital
NO
IC (IC105) is defective.
C216, C218, C221, C222, C223, C227, R157, R176, R186,
NO
R197, R142, R151, R152, and R154 are defective or mounted
improperly.
2 – 54
NO
YES
NO
YES
NO
YES