4. TROUBLE SHOOTING
- 67 -
(1) Checking VCTCXO Circuit
Graph 4-1(a)
Graph 4-1(b)
Test Points
Checking Flow
Circuit Diagram
Waveform
Check Pin 3.
Refer to Graph 4-1(b)
13 MHzO.K?
No
VCTCXO Circuit is OK
See next Page to check
ANT SW & Mobile SW
VCTCXO Circuit is OK
See next Page to check
ANT SW & Mobile SW
Yes
Yes
Check Pin 4.
Refer to Graph 4-1(a)
2.75V OK?
No
Changing X500
Check U101
(1005)
GND
3
OUT
4
VCC
1
VCONT
2V75_VVCXO
13MHz
X500
2
10K
R505
C529
1u
1M
C530
1000p
AFC
Z3X-BOX.COM
Summary of Contents for MG300d
Page 23: ...3 TECHNICAL BRIEF 24 Figure 3 1 SKY74400 FUNCTIONAL BLOCK DIAGRAM Z 3 X B O X C O M ...
Page 83: ...4 TROUBLE SHOOTING 84 4 6 LCD Trouble EMI FILTER CN600 Test Points Z 3 X B O X C O M ...
Page 110: ...5 DOWNLOAD AND CALIBRATION 111 8 Push the START button Z 3 X B O X C O M ...
Page 111: ...5 DOWNLOAD AND CALIBRATION 112 9 Phone test Finish is shown in below screen Z 3 X B O X C O M ...
Page 112: ...6 BLOCK DIAGRAM 113 6 BLOCK DIAGRAM Z 3 X B O X C O M ...
Page 113: ... 114 Z 3 X B O X C O M ...
Page 124: ... 125 MG300d 8 PCB LAYOUT Z 3 X B O X C O M ...
Page 125: ... 126 MG300d 8 PCB LAYOUT Z 3 X B O X C O M ...
Page 137: ... 138 Z 3 X B O X C O M ...
Page 138: ... 139 Z 3 X B O X C O M ...
Page 140: ... 141 12 EXPLODED VIEW REPLACEMENT PART LIST Z 3 X B O X C O M ...
Page 141: ... 142 Z 3 X B O X C O M ...