TROUBLESHOOTING
LCD
display does not light up.
|
||
YES
|
||
Is
5V applied to IC8001 pin 37?
|
NO
|
Check
STANDBY_5V line.
|
YES
|
||
Is
RESET signal released on IC8001 pin 36 (5V)?
|
NO
|
Check
line between IC501 and IC8001 pin 36.
|
YES
|
||
Is
38KHz oscillation signal output on IC8001 pin 41?
|
NO
|
Check
R8037 C8016, IC8001 and peripheral circuits.
|
YES
|
||
Are
the following signals input to each pin of IC8001?
IC8001
pin 44 LCD_DATA
IC8001
pin 43 LCD_CLK
IC8001
pin 42 LCD_CS
|
NO
|
Check
lines between pins of IC501 and IC8001.
IC501
pin 13 ® IC8001
pin 44 FIP DATA
IC501
pin 11 ® IC8001
pin 43 FIP CLK
IC501
pin 12 ® IC8001
pin 42 FIP_CS
|
YES
|
||
Are
the following signals input to each pin of LCD8003?
LCD8003
pin 33 COM1
LCD8003
pin 34 COM2
LCD8003
pin 35 COM3
|
NO
|
Check lines between pins of
IC8001 and LCD8003 as
well as IC8001. IC8001
pin 33 ® LCD8003
pin 33 COM1 IC8001
pin 34 ® LCD8003
pin 34 COM2 IC8001
pin 35 ® LCD8003
pin 35 COM3
|
YES
|
||
Check
display tube and main unit.
|
NO
|
Check
if display tube is damaged (cracked, etc.).
|
Operation
keys do not work.
|
||
YES
|
||
Is
key switch connected properly?
|
NO
|
Check
or replace key switch.
|
YES
|
||
Is
control voltage properly input to IC501 pin 87 and 88?
|
||
YES
|
||
Check
or replace IC501 peripheral circuits.
|
||
Power
does not turn on.
|
||
YES
|
||
Is
fuse normal?
|
NO
|
Replace
fuse. If the problem persists, refer to Flow chart No.18 "Fuse is
blown".
|
YES
|
||
Is
R903 normal?
|
NO
|
Is primary circuit part
leaking or short-circuited?
(L901,
D901, T901, IC901, etc.)
|
YES
|
NO
|
Is primary circuit part
leaking or short-circuited?
(L901,
D901, T901, IC901, etc.)
|
Are
voltages on AT40V, AT14V, AT5V and AT-8V normal?
|
NO
|
Check
rectification circuits of secondary side circuit.
|
YES
|
||
Is
IC501 pin 1 at "H" level?
|
NO
|
Check
power failure detection circuit (Q513 and IC506).
|
FUSE PROBLEM
|
||
CASE-1:
Is primary circuit
part leaking or short-circuited?
(L901,
D901, T901, IC901, etc.)
|
CASE-2:
Check the presence or
absence of rectifier diode and
short circuit in the
rectifier of the secondary circuit.
(D9001,9005,9007)
|
|
Power
does not switch from "OFF" to ON".
|
||
Is
AT5V normal?
|
NO
|
Refer
to Flow chart No.17 "Power does not turn on".
|
YES
|
||
Is
IC501 pin 94 at "H" level?
|
NO
|
Check
IC501 peripheral circuits.
|
YES
|
||
Is
ST_5V (STNDBY 5V) output?
|
NO
|
Check ST_5V SW circuit.
(Q9061,
Q9062, etc.)
|
YES
|
||
Is
IC501 pin 4 at "H" level?
|
NO
|
Check
IC501 peripheral circuits.
|
YES
|
||
Is
P-CON-H line at "H" level?
|
NO
|
Check
IC508 peripheral circuits.
|
YES
|
||
Are
AT_14V and PC_5V (1) output?
|
NO
|
Check
AT_14V line and PC_5V (1) circuit.
|
YES
|
||
Check
IC501 peripheral circuits.
|
||
