Motorola Xts5000 Detailled 6881094c31 E Manual
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November 16, 20066881094C31-E 5-30Troubleshooting Charts: VOCON RX Audio (for kit NNTN5567) VOCON RX Audio—Page 2 MAEPF-27395-O Make sure that you look at all solder contacts. Check resistors and capacitors associated with this check. If all look fine, then replace U502. Make sure that you look at all solder contacts. Check resistors and capacitors associated with this check. If all look fine, then replace U503. Signal Present? Check Preamp Output Signal at C530 No No No No No Ye s Ye s Ye sYe s Ye s 1 Preamp Gain = 2.8 V/V? PA Gain = 11.2 V/V?Distortion >3%?Check Preamp U502 and its associated components Check Flex ConnectorDistortion >3%?Check Audio PA U503 and its Components
6881094C31-ENovember 16, 2006 Troubleshooting Charts: RX RF5-31 5.14 RX RF—Page 1 Frequency OK? VHF: 44.85 MHz UHF R1/R2: 73.35 MHz 700-800: 109.65 MHz Inject a standard FM test signal into the antenna port. Use CPS to ensure that attenuator feature is disabled. Use a spectrum analyzer and high-impedance RF probe to measure the IF signal at TP12 (700-800) or TP15 (VHF) or TP455 (UHF R2) on side 2 No No Yes Yes Poor RX sensitivity or no RX audio Check RXLO Replace bad part Remove cable assembly, measure insertion lossVisual inspection OK? No Yes Bad antenna connector. Replace chassis (connector is not serviceable)Loss < 0.2 db?Replace cable assembl y No YesInspect coaxial antenna connector and cable assembly Measure RF input level at TP02 Measure RF levels at TP02 and TP13 (UHF Range 1 & 700-800) or TP401 (VHF or UHF Range 2), compute SW_FL lossRF level about -47 dBm? No Yes SW_FL loss < 2 dB?Check SW_FL Yes No IF level about -38 dBm?1 23 kHz FM deviation, 1 kHz rate, -47 dBm MAEPF-27470-C
November 16, 20066881094C31-E 5-32Troubleshooting Charts: RX RF RX RF—Page 2 Q501-c = 5.0 Vdc?No No No YesYes Yes Repair Defects Visual examination OK?Check Voltage Regulator U1 Q501-e = 3.7 Vdc?No YesReplace Q501 Replace Q502 Remove SH501 (UHF R1 & 700-800) or SH502 (VHF and UHF R2), inspect 2nd LO VCO Signal Present? Measure 2nd LO at TP501 (UHF R1 & 700-800) or TP18 (VHF and UHF Range 2) on PCB side 2 No No Yes Yes LO Freq. OK? VHF: 42.6 MHz UHFs: 71.1 MHz 700-800: 107.4 MHz Measure RXCK, P1-5 RXFS, P1-6 RXDO, P1-12 Observe 0 to 3 Vdc digital signals Measure bit clock rate (Fbit) at RXCKLevels OK? 1 3 5 No Yes RXFS = 20 kHz sync pulseFbit = 1.2 MHz? 4 No Yes No Yes RXFS OK?RXDO = 24-bit I, 24-bit Q, 8-bit AGC. AGC varies with RF level Go to VOCON RX AUDIO flowchartRXDO OK? 5 5 2nd LO, 700-800: 107.4 MHz, UHF R1/R2: 71.1 MHz, VHF: 42.6 MHz, about 356 mVp p 2nd LO DC bias MAEPF-27471-C
6881094C31-ENovember 16, 2006 Troubleshooting Charts: RX RF5-33 RX RF—Page 3 TP502 = 0 Vdc?No No YesYes Repair defects Measure RF levels at first preselector filter and compute filter loss. VHF & UHF2: TP401, TP9 UHF: TP13, U401-3 700-800: TP13, D401-3 No Yes Loss < 3 db? Measure RF levels at LNA and compute LNA gain. VHF & UHF2: TP9, TP12 UHF: U401-1, TP402 700-800: D401-3, TP402 Measure RF levels at second preselector filter and compute filter loss. VHF & UHF2: TP12, TP451 UHF: TP402, TP403 700-800: TP402, TP403Gain about +12 dB? 2 6 No Yes Measure RF and IF level at mixer and compute mixer conversion gain. VHF & UHF2: TP451, TP15 UHF R1: TP403, TP404 700-800: TP403, TP404Loss < 3 dB? 8No Yes Measure control voltage at TP502 No Yes Fvco too low? VHF: < 42.6 MHz UHF R1/R2: < 71.1 MHz 700-800: < 107.4 MHz Remove Abacus shield and inspect second LO VCO. VHF & UHF2: SH502 UHF R1/R2: SH501 700-800: SH501TP502 = 5 Vdc? 3 5 5 No Yes Replace Varactor D550 (D551 for UHF R2) Check LNA Check mixerVisual examination OK? No YesMeasure IF level at XTAL filter and compute XTAL filter loss. VHF & UHF2: TP15, TP455 UHF R1: TP404, TP12 700-800: TP404, TP12 Mixer gain about 4 dB? No Yes No problem foundLoss < 3 dB? 7 MAEPF-27472-C TP502 (Vdc)TP501 (MHz) Fvco 1.7 3.771.1 75.6 UHF R1 TP502 (Vdc)TP18 (MHz) Fvco 1.40 3.2042.6 47.1TP502 (Vdc)TP501(MHz)Fvco 0.00 1.85 4.30 5.00101.0 107.4 111.9 113.0 700-800 MHzVHFTP502 (Vdc)TP501 (MHz) Fvco 1.57 3.1171.1 75.6 UHF R2
November 16, 20066881094C31-E 5-34Troubleshooting Charts: RX RF RX RF—Page 4 Ye s Fbit < 1.2 MHz?Measure tuning voltage (Vt) at R512 No No No Ye s Ye s Vt= 3 Vdc? Repair defects Replace Varactor D501Replace Abacus U500Repair defects Visual examination OK? 4 Visual examination OK? Remove SH501, inspect components No Ye s5 5No Ye s Remove SH501, inspect clock oscillator circuit at U500-19, 20Vt = 0 Vdc? 5 Clock synthesizer MAEPF-27473-O
6881094C31-ENovember 16, 2006
Troubleshooting Charts: RX RF5-35
RX RF—Page 5
dac1 = dac2? Measure prselector filter
tuning voltage dac1 and dac2.
VHF & UHF2: None, TP29
UHF R1: TP401, TP405
700-800: TP401, TP405
No
Yes Is unit
VHF or UHF2?
No Yes
Replace IF filter.
VHF & UHF2: FL451
UHF R1: FL490
700-800: FL403Repair
defects
68
Visual
inspection
OK? Remove IF filter shield. Check IF
filter and LC matching networks.
VHF & UHF2: SH451
UHF R1: SH403
700-800: SH403
No
Yes
VHF/UHF: Check discrete
preselector filters.
700-800: Replace FL401
or FL402.Replace
PCIC Dac
voltages
OK? Tune the radio across several
channels. Measure dac2,
proportional to frequency.
No
Yes7
Replace
PCIC
MAEPF-27474-C
VHF
UHF R1
UHF R2
700-800
136
174
380
470
450
520
770
8691.3
2.4
0.5
2.9
1.2
3.6
1.5
3.5 Band F (MHz) dac2 (Vdc)
November 16, 20066881094C31-E 5-36Troubleshooting Charts: TX RF (VHF and UHF Range 2) 5.15 TX RF (VHF and UHF Range 2)—Page 1 TX power OK? Place XCVR and VOCON into the analysis fixture. Key up. Measure RF power at antenna port Ye s No Ye sNo No or low TX power Check FGU Frequency OK? No Ye sCheck FGU Level about -3 dBm?Check coaxial connector and cable assembly Measure RF level at Q107 pin 2 Use a spectrum analyzer and high-impedance RF probe. Measure TXRF at C016 Level about +15 dBm?NoNo Ye s Ye sLevel about 0 dBm? No Measure drain of Q104 Measure RF level at C147 Ye s Remove SH701 and check for parts off padCheck bias of Q101, Q103, and Q106. Replace bad transistors Is voltage 5 V? 1 2 MAEPF-27635-O
6881094C31-ENovember 16, 2006 Troubleshooting Charts: TX RF (VHF and UHF Range 2) 5-37 TX RF (VHF and UHF Range 2)—Page 2 MAEPF-27420-C RAWB+ about 7.2 Vdc? Measure RAWB+ at Q107-drain No No No YesYes Yes Check continuity V.gate about 2 to 3 Vdc?Check continuity DC bias is OK, control is OK, RFIN is OK, PA has low gain Replace Q107NoYesMeasure RF level at pin 6 of Q107 Is unit VHF or UHF R2? No YesRemove SH10 1and check for parts off pad Level about +35 dBm? Replace U102. For VHF and UHF Range 2, check under SH101. if all parts soldered, replace U102.Measure gate bias at L108 for VHF and L720 for UHF Range 2 RAWB+ about 7.2 Vdc? Measure RAWB+ at U102-6 No No Yes Yes TX7V about 7.2 Vdc?Check continuity Measure Vgate at TP111, normally 4 to 5.5 Vdc Measure TX7V at U102-14 DC bias is OK, control is OK, RFIN is OK, driver has low gainVgate > 4 Vdc? 21 3 4
November 16, 20066881094C31-E 5-38Troubleshooting Charts: TX RF (VHF and UHF Range 2) TX RF (VHF and UHF Range 2)—Page 3 INT > 5 Vdc? Vgate at TP111 is low (< 4 Vdc) Measure INT at TP104 Yes No No YesYesNoReplace Q108 INT is low. Measure VLIM at TP119 PCIC is programmed. Measure TEMP at R124Bad PCIC Replace U104 VLIM about 2 to 3 Vdc? No Yes Measure RFIN at TP101TEMP < 1.0 Vdc at 25C? RFIN is low, INT is low, bad PCIC, replace U104TP101 < 0.5 Vdc?Low output power, RFIN is high, check RF detectors and op amp U106. Repair defects Repair temperatur esensor circuit (U103, Q109, R130) 4 4 TXINH < 1 Vdc? TX7V is low. Measure TXINH at P1-19, Q101-b No No Yes Yes RXH < 1 Vdc? No YesBad PCIC Replace U104 RXH > 5 Vdc?Bad control signal from VOCON Trace dc levels through switching transistors Q101, Q102, Q103, and Q106 Replace bad transistors Measure RXH at U104-23 and Q103-b 3 MAEPF-27476-A
6881094C31-ENovember 16, 2006 Troubleshooting Charts: TX RF (UHF R1/700-800 MHz) 5-39 5.16 TX RF (UHF R1/700-800 MHz)—Page 1 TX power OK? Place XCVR and VOCON into the analysis fixture. Key up. Measure RF power at antenna port Ye s NoNo Ye s Ye sNo No or low TX power Check FGU Frequency OK? No Ye sCheck FGU Level about -3 dBm?Check coaxial connector and cable assembly Measure RF level at driver amp outlet, C107. Use a spectrum analyzer and high-impedance RF probe. Measure TXRF at TP11 RF level OK? Approx. +26 dBmNoNo Ye s Ye sLevel about +36 dBm? Check switch Measure RF levels at C103 and D701- cathode. Calculate switch loss Measure RF level at PA output, C103. Measure RF levels at D701-cathode and TP02. Calculate harmonic filter lossLoss < 1 db? No Ye s Go to VOCON TX AUDIO flowchartLoss < 2 db?Remove SH700, repair defects 1 2 MAEPF-27475-B