PMCE Customer Service 1 X500 RF Trouble Shooting - Lesson Four
X500 Training Course
RF Trouble Shooting
PMCE Customer Service 2 X500 RF Trouble Shooting - Lesson Four
RF & TX Part
RF & Transmitter FieldRF & Transmitter Field
PMCE Customer Service 3 X500 RF Trouble Shooting - Lesson Four
Receiver Flow Chart
U501
F501&F502
U503
Rx
PMCE Customer Service 4 X500 RF Trouble Shooting - Lesson Four
Receiver Flow Chart
Rx : Set RF Measure Instrument: HP8960 or HP8922
1. Operating mode Test mode , Test function TW
2. 900/1800 Bend: Ch 62 947.4MHz , Cell power -60dBm (Ch699: 1842.6MHz)
3 850/1900 Band: Ch 189 881.4MHz , Cell power -60dBm (Ch661: 1.96GHz)
PMCE Customer Service 5 X500 RF Trouble Shooting - Lesson Four
GSM Receiver Placement
Comparison ListLOC. Parts Description
Step 2 C540 CERAMIC CAPACITOR 33pF 50V 0402
Step 3 C702 CERAMIC CAPACITOR 22pF 50V 0402
Step 4 L510 INDUCTOR 12nH 0402
Step 5 TP501 RXIP test point
TP502 RXIN test point
TP503 RXQP test point
TP504 RXQN test point
PMCE Customer Service 6 X500 RF Trouble Shooting - Lesson Four
Receiver Flow Chart
Step 1. Check JP1 first, if we don’t insert RF cable, pin 1 must short to pin 2Step 2. Use probe, touch C540 pin 1 : ~ -61dBm GSM Freq = 947.4MHz DCS Freq = 1842.6MHz
S1
S2
PMCE Customer Service 7 X500 RF Trouble Shooting - Lesson Four
C540 pin 1, GSM Freq = 947.4MHz
PMCE Customer Service 8 X500 RF Trouble Shooting - Lesson Four
C540 pin 1, DCS Freq = 1842.6MHz
PMCE Customer Service 9 X500 RF Trouble Shooting - Lesson Four
Receiver Flow Chart
Step 3. Use probe to touch C702 : ~ -61dBm (GSM Freq = 947.4MHz)
Use probe to touch C555 : ~ -61dBm (DCS Freq = 1842.6MHz)
S3 (DCS)
S3 (EGSM)
PMCE Customer Service 10 X500 RF Trouble Shooting - Lesson Four
C702, GSM Freq = 947.4MHz
PMCE Customer Service 11 X500 RF Trouble Shooting - Lesson Four
C555, DCS Freq = 1842.6MHz
PMCE Customer Service 12 X500 RF Trouble Shooting - Lesson Four
Receiver Flow Chart
Step 4. Use probe to touch L510 : ~ -63dBm (GSM Freq = 947.4MHz) Use probe to touch L513 : ~ -62dBm (DCS Freq = 1842.6MHz)
S4 (DCS)
S4 (EGSM)
PMCE Customer Service 13 X500 RF Trouble Shooting - Lesson Four
L510, GSM Freq = 947.4MHz
PMCE Customer Service 14 X500 RF Trouble Shooting - Lesson Four
L513, DCS Freq = 1842.6MHz
PMCE Customer Service 15 X500 RF Trouble Shooting - Lesson Four
Receiver Flow Chart
Step 5. Check RX I and Q signal , Use probe to touch U501, Pin 55 to 58.
S5
PMCE Customer Service 16 X500 RF Trouble Shooting - Lesson Four
U501, Pin 55 to 58, RX I and Q signal
PMCE Customer Service 17 X500 RF Trouble Shooting - Lesson Four
Transmitter Flow Chart
S2
S3, S4
U503
U501
U502
PMCE Customer Service 18 X500 RF Trouble Shooting - Lesson Four
Transmitter Flow Chart
1. Operating mode Test mode , Test function TW
2. 900/1800 Bend: Ch 62 902.4MHz, Cell power -60dBm, MS_TX_level 5 Ch 699 1747.6MHz, Cell power -60dBm, MS_TX_level 0
3. 850/1900 Band: Ch 189 881.4MHz, Cell power -60dBm, MS_TX_level 5 Ch 691 1.96GHz, Cell power -60dBm, MS_TX_level 0
TX : Set Transmitter Measure Instrument: HP8960 or HP8922 TX
PMCE Customer Service 19 X500 RF Trouble Shooting - Lesson Four
GSM Transmitter Placement
Comparison ListLOC. Parts Description
Step 1 R515 ROW RESISTOR 6.8K F 4P2R 0404
R516 ROW RESISTOR 6.8K F 4P2R 0404
Step 2 R526 FIXED RESISTOR 510 1/16W 0402
Step 3 R538 SPECIAL FIXED RESISTOR 39 1/16W 0402
Step 4 R546 FIXED RESISTOR 1K 1/16W 0402
PMCE Customer Service 20 X500 RF Trouble Shooting - Lesson Four
Transmitter Flow Chart Step 1. Check TX I and Q first. If TX I & Q, are not normal, this is mostly caused by G2, and in some minor cases by IOTA.
S1
PMCE Customer Service 21 X500 RF Trouble Shooting - Lesson Four
TX I & Q signal
PMCE Customer Service 22 X500 RF Trouble Shooting - Lesson Four
Transmitter Flow Chart Step 2. Use Oscilloscope probe to touch R526 : ~ 1.5V (for GSM) Use Oscilloscope probe to touch R526 : ~ 1.7V (for DCS)
S2
PMCE Customer Service 23 X500 RF Trouble Shooting - Lesson Four
R526 for GSM
PMCE Customer Service 24 X500 RF Trouble Shooting - Lesson Four
R526 for DCS
PMCE Customer Service 25 X500 RF Trouble Shooting - Lesson Four
Transmitter Flow Chart Step 3. Use probe to touch R538 : ~7 dBm, check PA_GSM_input (Freq = 902.4MHz) R540 : ~0 dBm, check PA_DCS_input (Freq = 1747.6MHz) If S2 and S3 are both ok, mean Transceiver is ok.)
S3 (EGSM)
S3 (DCS)
PMCE Customer Service 26 X500 RF Trouble Shooting - Lesson Four
R538 for GSM
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R540 for DCS
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Transmitter Flow Chart
Step 4. Press TX_APC(350), use Oscilloscope probe to touch R546 : ~ 0.8V, Then, press TX_APC(550), and touch R546 : ~ 1.3V
S4
Note:
APC controls PA output power. If PA has not enough power or no power, we must check S3 and S4. When APC is increased,the voltage of S4 will be increased as well. It means S4 is normal.
PMCE Customer Service 29 X500 RF Trouble Shooting - Lesson Four
R546 for TX_APC(350)
PMCE Customer Service 30 X500 RF Trouble Shooting - Lesson Four
R546 for TX_APC(550)
PMCE Customer Service 31 X500 RF Trouble Shooting - Lesson Four
DCS Receiver Placement
Comparison ListLOC. Parts Description
Step 2 C540 FIXED RESISTOR 18 1/16W 0402
Step 3 C555 FIXED RESISTOR 0 J 1/16W 0402
Step 4 C513 CERAMIC CAPACITOR 22pF 50V 0402
Step 5 TP501 RXIP test point
TP502 RXIN test point
TP503 RXQP test point
TP504 RXQN test point
PMCE Customer Service 32 X500 RF Trouble Shooting - Lesson Four
DCS Transmitter Placement
Comparison ListLOC. Parts Description
Step 1 R515 ROW RESISTOR 6.8K F 4P2R 0404
R516 ROW RESISTOR 6.8K F 4P2R 0404
Step 2 R526 FIXED RESISTOR 510 1/16W 0402
Step 3 R540 FIXED RESISTOR 18 1/16W 0402
Step 4 R546 FIXED RESISTOR 1K 1/16W 0402
PMCE Customer Service 33 X500 RF Trouble Shooting - Lesson Four
Any Questions?