LG LX-U250A Service Manual page 10

" READING " DISPLAY CHECK
(= ONLY "CD "DISPLAY)
CONNECTOR LOCKING CHECK (PN802,
PN804,PN805,PN806 )
CHECK POWER SUPPLY
PORT( PN805 ,PN806)
PN 806 PIN 4 = 12V, PIN 5 = 6.2V
PN805 PIN 12 = 5V
CHECK VOLTAGE THE PIN 2 OF IC804
IC804 PIN 2 : 3.3V
CHECK RESET SIGNAL OF PN805
PN805 PIN 4 : 3V
CHECK MICOM INTERFACE
CIRCUIT( PN805 )
PN805 PIN 3,4,5,6,7,8,9 SIGNAL CHECK
(3: WRQ, 4 : RESET 5 : DO, 6: DI, 7 : CL
8: CE, 9: FSEQ)
CHECK THE WAVE FORM #1
- 2-3 -
DEFECTIVE CONNECTOR OR
MAIN POWER SUPPLAY
DEFECTIVE IC804
DEFECTIVE MICOM OR
CONNECTOR
DEFECTIVE MICOM OR
CONNECTOR
DEFECTIVE IC801