LG MAX221UB Service Manual

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

LG MAX221UB Specifications

General

Brand	LG
Model	MAX221UB
Category	Receiver
Language	English