Motorola Gm328 Gm338 Gm398 Detailed 6804112j18 E Manual
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Troubleshooting Flow Chart for 25W Transmitter 3-3 2.0 Troubleshooting Flow Chart for 25W Transmitter (Sheet 1 of 3) Current increase when keyed? NO YES START Check if Pressure Pad closes S3440 Check Components between Q3441 and RF Output, Antenna Switch D3471,D3472,Q3472 VR3471,Q3471>500mA & 4A 1V Short TP3403 to Ground NO YES Voltage at TP3402 rises?Check PA StagesNO YES PCIC U3501 Pin 14 9.3V DC?Check 9.3 V Regulator U0641 NO YESPCIC U3501 Pin 16 >4V DCReplace PCIC U3501 NO YESTP3404...
Page 162
3-4 Troubleshooting Flow Chart for 25W Transmitter 2.1Troubleshooting Flow Chart for 25W Transmitter (Sheet 2 of 3) Check PA Stages No or too low Power when keyed Measure DC Voltage at Pin 2 & 3 of U3401>6 YESDC Voltage at U3501 Pin 23 =0? 2-6DC Voltage at U3402-1 Pin 1? YESPin 2 Volt- age 0.62 * Voltage at Pin 1? If U3201 Pin 2 is high, replace PCIC NOReplace U3401 YES NODC Voltage at U3402-1 Pin 3 = 8.8V? Check S3440, R3442 and R3443 YESPin 3 Volt- age 0.51 * Voltage at Pin 1? NOReplace...
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Troubleshooting Flow Chart for 25W Transmitter 3-5 2.2Troubleshooting Flow Chart for 25W Transmitter (Sheet 3 of 3) Check Final PA Stage NO 0V 1-4VBias 2 DC Voltage at TP3406? YESRF Voltage at TP3401 >100mV? YESRF Voltage U3401 Pin 6 >3V? Supply Replace Q3441 Check FGU (U3301) NOCheck Components between TP3401 & C3417 NO YESASFIC U0221 Pin 6 1-4V DC? Check Bias Tuning before replacing ASFIC U0221 Check Components between ASFIC and Q3441 before replacing Q3441 YESRF Voltage Q3421 Gate...
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3-6Troubleshooting Flow Chart for Synthesizer 3.0 Troubleshooting Flow Chart for Synthesizer +5V at U3201 Pins 13 & 30? 5V at pin 6 of D3201 Is information from µP U0101 correct? Is U3201 Pin 47 = 13VDC ? Is U3301 Pin 19 4.5 VDC in TX? (at VCO section) Sta rt Visual check of the Board OK?Correct Problem Check 5V Regulator U3211 Is 16.8MHz Signal at U3201 Pin 19? Check Y3261, Y3263 and associated parts Are signals at Pins 14 & 15 of U3201? Check R3201 Check C3319Is U3201 pin 2 >4.5 VDC in Tx...
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Troubleshooting Flow Chart for VCO3-7 4.0 Troubleshooting Flow Chart for VCO Are Q3301 Base at 0.7V Collector at 4.5V Emitter at 110mV Are Q3304 Base at 2.4V Collector at 4.5V Emitter at 1.7VAre U3301 Pins 13 at 4.4V 15 at 1.1V 10 at 4.5V 16 at 1.9V Low or no RF Signal at TP3001 Visual check of board OK? 35mV DC at U3301 Pin 19 NO YES at base of Q3301 NO NO NO NONO YES YES YES YESYESLow or no RF Signal at input to PA5V DC at U3301 Pin 14 & 18 OK ? 4.8V DC at U3301 Pin 19 Is RF available at TP3401...
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4-1 Section 4 VHF PCBS/SCHEMATICS/PARTS LISTS 1.0 Allocation of Schematics and Circuit Boards 1.1 Controller Circuits The VHF circuits are contained on the Printed Circuit Board (PCB) which also contains the Controller circuits. This Chapter shows the schematics for the VHF circuits only, refer to the Controller section for details of the related Controller circuits . The PCB component layouts and the Parts Lists in this Chapter show both the Controller and VHF circuit components. The VHF schematics...
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VHF 1-25W PCBs / Schematics / Parts Lists4-32.0 VHF 1-25W PCBs / Schematics / Parts Lists VCO-REV-T3 PA-REV-T1FE-REV-T3 IF-REV-T4 FRAC-T4 CNTL-REV-T6 C0101C0102C0104 C0106 C0107 C0131C0132C0211 C0212 C0221C0222 C0223 C0224C0225 C0226 C0227 C0228 C0231 C0232 C 0233 C0234C0235 C0236C0237 C0241 C0242 C0243 C0244 C0245C0246 C0251 C0252 C0253C0261 C0262C0267 C0421 C0441 C 0442 C 0443 C 0445 C 0446 C 0447 C 0448 C 0449 C 0470 C 0471 C 0472 C 0473 C 0474 C 0476 C 0477 C 0478 C0482 C0483 C0484...
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4-4VHF 1-25W PCBs / Schematics / Parts Lists C0103C0105 C0111 C0112C0121 C0122 C0123 C0141 C0151 C0201C0202 C0203 C0204 C0205 C0254C0255 C0265 C0266 C0271C0272 C0273C0274 C0275 C0276 C0277 C0301 C0302 C0303C0304 C0305 C0324C0325 C0331 C0341 C0342 C0343 C0344 C0351 C0352 C0353 C0354 C0422 C0423 C 0426 C 0427 C 0428 C 0429 C0430 C0431 C0485 C0491 C0492 C0497 C0499C0541C0554 C0558 C0559C0560C0575 C0576 C0591 C0592C0593 C0611 C0621C0622 C0641 C0644 C0645 C0661 C0662 C0663 C0671 C3000 C3001C3003...