Electrical Troubleshooting Guide; System Control Error Correction Flow Chart - LG MAX220UB Service Manual

ELECTRICAL TROUBLESHOOTING GUIDE

1. SYSTEM CONTROL ERROR CORRECTION FLOW CHART

Something wrong with the System control?
No power?
YES
Checked the Fuse?
YES
Checked the Back up
VDD and GND?
YES
Checked the Regulator
Back up VDD?
YES
Checked the Main Micom
B+ Detect?
YES
Checked the Main
Micom VDD?
YES
Checked the Main
Micom GND?
YES
Checked the Main
Micom reset?
YES
Checked the Main
Micom X-tal?
YES
Checked the ACC in?
YES
Checked the Front
Panel Key input?
YES
OK
SECTION 2 ELECTRICAL
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
1A 1B 1C
F301 Inside of JK801
JK801(1, 2, 3, 4)
IC801(15, 14)
IC401(14, 40, 55, 89)
IC401(11, 39, 56, 88)
IC401(8), IC402
Q802, R459, IC401(3)
IC401(15, 16), CN402(7, 8)
2-1
1D 1E
IC401(4, 21)
X401, X402