LG MCV902 Service Manual page 54

1-2. "READING" DISPLAY CHECK (= ONLY "CD" DISPLAY)
CONNECTOR LOCKING CHECK
(PN802, PN803, PN804, PN805, CN806 )
CHECK POWER
SUPPLY PORT( PN805, CN806)
CN806 PIN1 : 12V, PIN2 : 6.3V,
PIN4 : 5V PN805
PIN8 = 5V_AD
CHECK VOLTAGE
THE PIN 2 OF IC804
IC804 PIN2 : 3.3V
CHECK RESET
SIGNAL OF PN805
PN805 PIN19 : 5V
CHECK
MICOM INTERFACE
CIRCUIT(PN805) PN805 PIN1,
3, 4, 15, 19, 26 SIGNAL CHECK
(1 : CE, 3 : DI, 4 : CLK, 15 : D0, 19 : RST,
18 : FSEQ, 26 : WRQ) PIN3 DI : From DSP
to Micom PIN15 DO : From Micom
to DSP CHECK THE
WAVE FORM
#1
DEFECTIVE IC801
YES
YES
YES
YES
YES
NO
DEFECTIVE CONNECTOR OR
MAIN POWER SUPPLAY
NO
DEFECTIVE IC804
NO
DEFECTIVE MICOM OR CONNECTOR
NO
DEFECTIVE MICOM OR CONNECTOR
4-3