Sharp GX15, Service Manual

Page: 62 / 122

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