13
5. TROUBLE SHOOTING CHART
5-1.Panel Control Circuit:
No Display
Replace panel or FFC
cable to panel
Replace L118, C137
Check U300 crystal
X300 (12MHZ)
Replace X300
Check 2.5V L301-L304
3.3V L305-L308
Replace components
if it has problem
Replace U300
OK
OK
OK
OK
NG
NG
NG
NG
Check CN101 pin 42-45
is 5V and signal on pin
35,37,39,40,25-28,30-33,15-
18,20-23,5-8,10-13
Check U300 Output to
CN101 relative circuit and
CN101 VCC at Q300,
Q301, L309 (5V)
Summary of Contents for PB20C
Page 15: ...14 5 2 Main Board Power Circuit 5 3 Remote Control Block ...
Page 16: ...15 5 4 Key Board Control Block 5 5 PC Control Block ...
Page 17: ...16 ...
Page 18: ...17 5 6 Audio Control Block ...
Page 22: ...21 7 SOFTWARE FLOW CHART ...
Page 23: ...22 ...
Page 24: ...23 ...
Page 26: ...25 8 2 POWER BOARD BLOCK DIAGRAM ...
Page 44: ...43 9 3 KEY BOARD SCHEMATIC DIAGRAM ...
Page 45: ...44 9 4 HEADPHONE JACK BOARD SCHEMATIC DIAGRAM ...
Page 46: ...45 9 5 IR BOARD SCHEMATIC DIAGRAM ...
Page 47: ...46 10 MECHANICAL OF CABINET FRONT DIS ASSEMBLY ...
Page 79: ...78 12 PCB LAYOUT 12 1 MAIN BOARD PCB LAYOUT ...
Page 80: ...79 12 2 PWPC BOARD PCB LAYOUT ...