Sharp GX20 Service Manual - Page 61

No Service display and, receiving/transmitting do not function.

Get Sharp GX20 PDF manuals and user guides View all Sharp GX20 manuals
Add to My Manuals
Save this manual to your list of manuals

Page 61 highlights

CONFIDENTIAL 10. "No Service" display and receiving/transmitting do not function. 10.1. "No Service" display and receiving/transmitting do not function in the EGSM band. [Checkpoints for GSM tester transmission] Fixed line: During input of -70 dBm. GX20 After replacing the main PWB unit with normal one, trans- YES mission with GSM tester possible? NO NO After replacing FPC (flexible printed circuit) with normal YES one, transmission with GSM tester possible? [Checkpoints in RF Test Tool] [Transmitting System] Is transmission possible using RF Test Tool? YES NO Voltage applied to VCO971 7 pin? NO YES Is VCO971 frequency fixed at 4 times as the EGSM-band NO transmitting frequency + 80 MHz (or 82 MHz)? YES IQ Signal input to IC901 20, 21, 22, and 23 pins? NO YES Voltage applied to VCO851 11 pin? NO YES EGSM-Band Transmitting frequency input to IC831 1 pin? NO YES EGSM-Band Transmitting frequency input to FL801 11 NO pin? YES EGSM-Band Transmitting frequency input to J801 1 pin? NO YES J801 defective. [Receiving System] Fixed line: During input of -70 dBm. Voltage applied to VCO971 7 pin? NO YES Is VCO971 frequency fixed at 4 times as the EGSM band NO receiving frequency? YES EGSM-Band Receiving frequency signal applied to IC901 YES 10 and 11 pins? NO EGSM-Band Receiving frequency signal output from YES FL801 7 pin? NO EGSM-Band Receiving frequency signal input to FL801 9 YES pin? NO J801 or FL817 defective. 2 - 55 IC104, IC102, CN201, CN202, or PWB defective. FPC defective. IC202, IC303, Q304, or Q308 defective. IC901, VCO971, FL971, TCX951, or IC304 defective. IC104, IC102, or PWB defective. Q304 or Q309 defective. VCO851, IC901, or IC993 defective. FL811, R811, IC831, IC881, or IC992 defective. IC991, IC992, IC993, FL801 or FL817 defective. IC202, IC303, Q304, or Q308 defective. IC901, VCO971, FL971, TCX951, or IC304 defective. IC104, IC102, IC901, or PWB defective. FL901 defective. IC991, IC992, IC993, or FL801 defective.

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
  • 154
  • 155
  • 156
  • 157
  • 158
  • 159
  • 160
  • 161
  • 162
  • 163
  • 164
  • 165
  • 166
  • 167
  • 168
GX20
2 – 55
CONFIDENTIAL
10.
"No Service" display and
receiving/transmitting do not function.
10.1. "No Service" display and receiving/transmitting do not function in the EGSM band.
[Checkpoints for GSM tester transmission]
Fixed line: During input of –70 dBm.
After replacing the main PWB unit with normal one, trans-
mission with GSM tester possible?
IC104, IC102, CN201, CN202, or PWB defective.
After replacing FPC (flexible printed circuit) with normal
one, transmission with GSM tester possible?
FPC defective.
[Checkpoints in RF Test Tool]
[Transmitting System]
Is transmission possible using RF Test Tool?
Voltage applied to VCO971 7 pin?
IC202, IC303, Q304, or Q308 defective.
Is VCO971 frequency fixed at 4 times as the EGSM-band
transmitting frequency + 80 MHz (or 82 MHz)?
IC901, VCO971, FL971, TCX951, or IC304
defective.
IQ Signal input to IC901 20, 21, 22, and 23 pins?
IC104, IC102, or PWB defective.
Voltage applied to VCO851 11 pin?
Q304 or Q309 defective.
EGSM-Band Transmitting frequency input to IC831 1 pin?
VCO851, IC901, or IC993 defective.
EGSM-Band Transmitting frequency input to FL801 11
pin?
FL811, R811, IC831, IC881, or IC992 defective.
EGSM-Band Transmitting frequency input to J801 1 pin?
IC991, IC992, IC993, FL801 or FL817 defective.
J801 defective.
[Receiving System]
Fixed line: During input of –70 dBm.
Voltage applied to VCO971 7 pin?
IC202, IC303, Q304, or Q308 defective.
Is VCO971 frequency fixed at 4 times as the EGSM band
receiving frequency?
IC901, VCO971, FL971, TCX951, or IC304 defective.
EGSM-Band Receiving frequency signal applied to IC901
10 and 11 pins?
IC104, IC102, IC901, or PWB defective.
EGSM-Band Receiving frequency signal output from
FL801 7 pin?
FL901 defective.
EGSM-Band Receiving frequency signal input to FL801 9
pin?
IC991, IC992, IC993, or FL801 defective.
J801 or FL817 defective.
YES
NO
NO
YES
YES
NO
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
YES
NO
YES
NO
YES
NO