QSC_CX_Series_Service_Manual 电路图.pdf

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1、CX Series CX4 CX12 RadioFans.CN 收音机爱好者资料库 CX Series CX4T CX1 2T RadioFans.CN 收音机爱好者资料库 CX SERIES AMPLIFIER SERVICE MANUAL CX4 - CX4T CX6 - CX6T CX12 - CX12T QSC Technical Services Wats: 1-800-772-2834 Local: 1- 714- 957- 7150 Fax: 1-714-754-6173 QSC Online! Online Computer Information System 1- 80

2、0- 856- 6003 I- 71 4- 668- 7567 QSC Audio Products, Inc. 1675 MacArthur Blvd. Costa Mesa, CA 92626 RadioFans.CN 收音机爱好者资料库 CX Series Chassis Drawings CX4 Chassis Assembly .42 CX4T Chassis Assembly .45 CX6 direct outputs 45Hz* - 16kHz, +0, 3dB ; isolated outputs *Low Frequency is limited by 18 dB/oct

3、ave 45 Hz high pass filter 200 ( direct outputs) 1 00dB below rated output (20 Hz to 20 kHz) 10k ohms unbalanced and 20k balanced Standard 19” Rack Mounting 3.5” (13.3 cm) 5.25” (13.3 cm) 17.9” (45.5 cm) 17.9” (45.5 cm) 46/2162/28 40/18.255/25 5.25” (13.3 cm) 17.9” (45.5 cm) 75/34 67/30.4 CX Series

4、I n t r o d u c t i o n This manual is prepared to assist service personnel with the repair and calibration of the CX Series power amplifiers The procedures described in this manual require advanced technical experience and sophisticated audio test equipment. AA CAUTION: To reduce the risk of electr

5、ic shock, do not remove the cover. No user- serviceable parts inside. Refer servicing to qualified service personnel. WARNING: To prevent fire or electric shock, do not expose this equipment to rain or moisture. Documentation This manual contains schematics, printed circuit board (PCB) drawings, par

6、ts lists, and mechanical assembly drawings. This information should be used in conjunction with the test and troubleshooting guide. The electrical and electronic components are identified by circuit identification numbers on the schematics and the parts list, The test if over 3VDC present, the prote

7、ction circuit is operating normally to hold of operation. See DC FAULT WITHOUT CURRENT DRAW section to fix this DC fault. l RELAY WONT TURN ON WITH NORMAL OPERATING AMPLIFIER: 1 .Check Relay power voltage. With relay off, voltage at C516 should measure about 47VDC. With relay on, C516 should measure

8、 about 27V. if not check D516, R531, C516, D515. 2. If relay power voltage OK; check voltage on the timing capacitor C515. Should rise to 12- 15VDC, in three seconds, which triggers Q513. If not check R528, R530, C515 polarity 3.Timing voltage OK; check relay transistor Q512. If good, RN501 B- C res

9、istors from base to speaker bus should activate relay. 4. Relay driver Q512 OK, check driver Q513 and LD1 01. l NO RED “PROTECT” LED 1. Check LED voltage, If over - 2V, LED is defective. If OV with relay off (no negative voltage to LED), there is no “protect” power (open or missing R534), which defe

10、ats shutdown circuits. Be sure to correct before proceeding. l NO MUTING DELAY (be sure “protect” LED works) ALSO WITHOUT THERMAL OR DC PROTECT: relay or circuit is “stuck on! 1, Relay Q512 shorted or wrongly mounted. Check by jumping base to emitter, should turn it Off. 2. Relay Q513 shorted or wro

11、ngly mounted. Check by jumping base to emitter, should turn it Off. NO MUTING DELAY ONLY (all else OK): 1. D518 reversed ( charges timing capacitor C515 immediately) 2. R528 low (fast C515 charge) 3. R29 low (low voltage on E7 turns Q513 on too soon), missing or high R30 (no off current). EXCESS MUT

12、ING DELAY: 1. Check timing capacitor E515 voltage, If it rises normally but circuit is slow to turn on, check D517 (lift temporarily), LD501 bad or intermittent, RN501 D too low. 2. Timing capacitor voltage wrong; determine cause (R528, R530, reversed C515, reversed or wrong Q511. l NO THERMAL SHUTO

13、FF Short the amplifier load with full signal to raise heatsink temperature and put voltmeter across PTC R516 or input RN902, (CX4/T) RN500 is wrong value. (Faulty input resistors will cause the amplifier to fail the Common Mode test.) 2. Too low: Above feedback values wrong or shunt resistor R541/C5

14、20, (CX4/T) R523 wrong or open (open causes very low gain with instability. Check circuit trace). l POOR FREQUENCY RESPONSE (Be sure to correct any gain problem first) 1. High frequency, determined by feedback capacitor C519, (CX4/T) C516 (wrong value also causes instability) 2. Low frequency, deter

15、mined by DC feedback rolloff C520, and “butterworth” feedback compensation network C518/R542. (CX4/T) C502 low frequency rolloff. l STEP CIRCUIT (CX12/T only) Check step circuit components U501, U502, Q503, Q504 carefully, note exact output voltage where step cuts in (are both matched to 1V). Step t

16、urning on too late (too high) will hang up at 2 ohms. Check referent 15V zener voltages D509 and D510. After inspecting all parts, see below: 1. Step distortion: check step filter components R508/C505, R504/C501, and C528. 19 CX Series 2. No step: check 0503, Q504, U501, U502 burned to open. R505, R

17、506, R510 open. Instability (Gain problems, spurious noises, and oscillations) All Models l General Output Distortion l Excessive or unbalanced crossover - Output waveform appears “fuzzy” Possible Causes: First, distinguish between instability (fuzziness), “ringing” which is momentary instability af

18、ter a transition, step” distortion, crossover distortion (both often show ringing), or general distortion. l GENERAL OUTPUT DISTORTION SEVERE: All loads, often with current draw: often associated with feed back components (U503, C532, C520, C519, C518, C523). (CX4/T) U501, C516, C505. Check resistor

19、 values on R540, R541, R542, R568, R538, R547. (CX4/T) R502, R523, R524. MEDIUM: Check feedback capacitor C519. (CX4/T) C516, LOW GAIN: Suspect open circuit in feedback shunt R541 and C520. (CX4/T) R523. Check for broken circuit trace. Substitute IC and check IC socket for contamination. l EXCESSIVE

20、 OR UNBALANCED CROSSOVER (Excess notch or ringing at zero crossing) 1. Severe: shorted bias diode D505, D506. (CX4/T) D504, D505. 2. Moderate: Out- of- spec bias diodes. 3. Defective bias trimmer components VR501, R511. (CX4/T) R512, R532. 4. Check for open base resistors R517, 518 on output devices

21、. (CX4/T) R504, R527. l OUTPUT WAVEFORM APPEARS FUZZY 1. Check main heatsink ground continuity with chassis ground, 2. High frequency snubbers defective (C513, C514, R525, R526, R523, R527). (CX4/T) R520, C515. 3. Check capacitors on speaker output board. 4. Check/adjust driver emitter capacitors C5

22、19 and C523. (CX4/T) C516, C505. 20 CX Series Power Supply and Voltage Rail Balancing (Uneven rails and power supply problems) Symptoms: - Current limiting wrong l Current limiting too high into a short . IC rail too high into a short - Current limiting too low into a short l Uneven voltage rails Po

23、ssible Causes: l CURRENT LIMITING WRONG Current limits should remain high down to 2 ohms, and collapse to a lower value for short circuits. This is caused by the IC rails going from normal 14 - 1.5 volts to about 5- 6 volts. Current limit trimmers TR502 “. , , CX Series Voltage Conversion PARTS REQU

24、IRED FOR 230 V OPERATION FROM 12OV (Please refer to CX Series wiring diagrams in this manual for AC Voltage drawings) Model CX4/4T Part Number Description LB- 000099- 00 LABEL, CE LISTING 95 PS- 000038- 00 SERIAL LABEL WC- 003069- 00 AC POWER CORD, EXPORT NOTE: 1, Replace the cUL label with a CE lab

25、el on the rear panel. 2, Replace the serial label with appropriate VOLTAGE and CURRENT listing label. Qty Reference 1 CHASSIS 1 CHASSIS 1 CHASSIS Model CX6/6T Part Number Description Qty Reference LB-000099- 00 LABEL, CE LISTING 95 1 CHASSIS LB- 1 60226- 02 LABEL FUSE, 12A 250V 1 AC PCB MS- 1 20250-

26、 FU12A 25OV, FUSE 1F901 PS- 000038- 00 SERIAL LABEL 1 CHASSIS RE-000160- NT THERMISTOR NTC 15A 1R901 WC-003069-00 AC POWER CORD, EXPORT 1 CHASSIS NOTE: 1, Replace the cUL label with a CE label on the rear panel. 2. Replace the serial label with appropriate VOLTAGE and CURRENT listing label. 3, Place

27、 a 12A FUSE label on the AC PCB, overlapped the 2OA fuse label. Model CX12/12T Part Number Description Qty Reference LB-000099- 00 LABEL, CE LISTING 95 1 CHASSIS LB- 160226- 01 LABEL FUSE, 15A 250V 1 AC PCB MS- 1 50250- FU15A 25OV FUSE 1F901 PS-000038-00 SERIAL LABEL 1 CHASSIS RE- 000160- NT THERMIS

28、TOR NTC 15A 1R901 WC- 00306940 AC POWER CORD, EXPORT 1 CHASSIS NOTE: 1, Replace the cUL label with a CE label on the rear panel. 2, Replace the serial label with appropriate VOLTAGE and CURRENT listing label. 3, Place a 15A FUSE label on the AC PCB, overlapped the 3OA fuse label. 23 CX Series CX Ser

29、ies Voltage Conversion PARTS REQUIRED FOR 1 OOV OPERATION FROM 12OV (Please refer to CX Series wiring diagrams in this manual for AC Voltage drawings) Model CX4/4T Part Number Description PS- O00038xI0 SERIAL LABEL NOTE: 1. Remove the cUL label on the rear panel 2. Replace the serial label with appr

30、opriate VOLTAGE and CURRENT listing label. QtY Reference 1 CHASSIS Model CX6/6T Part Number Descriotion Gtv Reference PS-000038-00 NOTE: SERIAL LABEL 1 CHASSIS 1. Remove the cUL label on the rear panel 2. Replace the serial label with appropriate VOLTAGE and CURRENT listing label. Model CX12/12T Par

31、t Number Description PS- 000038- 00 SERIAL LABEL NOTE: 1. Remove the cUL label on the rear panel 2. Replace the serial label with appropriate VOLTAGE and CURRENT listing label. Qty Reference 1 CHASSIS CX Series Voltage Conversion PARTS REQUIRED FOR 12OV OPERATION FROM 1 OOV (Please refer to CX Serie

32、s wiring diagrams in this manual for AC Voltage drawings) Model CX4/4T Part Number Description LB-000052-00 LABEL, cUL APPROVAL PS- 000038-00 SERIAL LABEL NOTE: 1. Place a cUL label on the rear panel, next to the AC cord. 2. Replace the serial label with appropriate VOLTAGE and CURRENT listings. Qty

33、 Reference 1 CHASSIS 1 CHASSIS Model CX6/6T Part Number LB-OOOO52-00 PS-000038- 00 NOTE: Description Qty Reference LABEL, cUL APPROVAL 1 CHASSIS SERIAL LABEL 1 CHASSIS 24 1. Place a cUL label on the rear panel, next to the AC cord. 2. Replace the serial label with appropriate VOLTAGE and CURRENT lis

34、tings. Model CX12/12T Part Number Description LB-000052-00 LABEL, cUL APPROVAL PS-000038-00 SERIAL LABEL NOTE: 1, Place a cUL label on the rear panel, next to the AC cord. 2. Replace the serial label with appropriate VOLTAGE and CURRENT listings. Qty Reference 1 CHASSIS 1 CHASSIS CX Series Voltage C

35、onversion PARTS REQUIRED FOR 100V OPERATION FROM 230V (Please refer to CX Series wiring diagrams in this manual for AC Voltage drawings) Model CX4/4T Part Number Description PS- 000038- 00 SERIAL LABEL WC- 003070- 00 AC POWER CORD, EX/MX SERIES NOTE: 1, Remove the CE label on the rear panel. 2, Repl

36、ace the serial label with an appropriate VOLTAGE and CURRENT listing label. Qty Reference 1 CHASSIS 1 CHASSIS Model CX6/6T Part Number Description MS- 000050-MS2OA, 25OV FUSE PS- 000038- 00 SERIAL LABEL RE-000170-NR THERMISTOR NTC 30A WC- 00307040 AC POWER CORD, EX/MX SERIES NOTE: 1, Remove the CE l

37、abel on the rear panel. 2, Replace the serial label with an appropriate VOLTAGE and CURRENT listing label. 3, Remove the FUSE label on the AC PCB Qty Reference 1 F901 1 CHASSIS 1 R901 1 CHASSIS Model CX12/12T Pan Number Description MS-000055-MS3OA, 125V FUSE LB- 1 60226- 00 LABEL, FUSE, 30A 125V PS-

38、 000038- 00 SERIAL LABEL Qty Reference 1 F901 1 AC PCB 1 N/A RE-000170-NR THERMISTOR NTC 30A 1R901 WC- 003070- 00 AC POWER CORD, EX/MX SERIES 1 CHASSIS NOTE: 1, Remove the CE label on the rear panel. 25 CX Series 2, Replace the serial label with an appropriate VOLTAGE and CURRENT listing label. 3. P

39、lace a 30A FUSE label on the AC PCB, overlapped the 15A fuse label CX Series Voltage Conversion PARTS REQUIRED FOR 230V OPERATION FROM 1OOV (Please refer to CX Series wiring diagrams in this manual for AC Voltage drawings) Model CX4/4T Part Number Description LB-000099-00 LABEL, CE LISTING 95 PS- 00

40、0038- 00 SERIAL LABEL WC-003069-00 AC POWER CORD, EXPORT NOTE: 1, Place a CE label on the rear panel, next to the AC cord. 2, Replace the serial label with appropriate VOLTAGE and CURRENT listing label. Qty Reference 1 CHASSIS 1 CHASSIS 1 CHASSIS Model CX6/6T Part Number Description Qty Reference LB

41、-00009940 LABEL, CE LISTING 95 1 CHASSIS LB-16022642 LABEL FUSE, 12A 25OV 1 AC PCB MS- 1 20250-FU12A 250V, FUSE 1F901 PS-000038-00 SERIAL LABEL 1 CHASSIS RE-000160-NT THERMISTOR NTC 15A 1R901 WC- 003069- 00 AC POWER CORD, EXPORT 1 CHASSIS NOTE: 1, Place a CE label on the rear panel, next to the AC c

42、ord. 2. Replace the serial label with appropriate VOLTAGE and CURRENT listing label. 3, Place a 12A FUSE label on the AC PCB, overlapped the 20A fuse label. Model CX12/12T Part Number Description Qty Reference LB-000099-00 LABEL, CE LISTING 95 1 CHASSIS LB-16022641 LABEL FUSE, 15A 250V 1 AC PCB MS-

43、1 50250-FU15A 25OV FUSE 1F901 PS- 000038- 00 SERIAL LABEL 1 CHASSIS RE-000160-NT THERMISTOR NTC 15A 1R901 WC-003069-00 AC POWER CORD, EXPORT 1 CHASSIS NOTE: 1. Place a CE label on the rear panel, next to the AC cord. 2. Replace the serial label with appropriate VOLTAGE and CURRENT listing label. 3,

44、Place a 15A FUSE label on the AC PCB, overlapped the 30A fuse label. 26 CX4/4T Input Assembly WP-000047-00 CX4/4T INPUT PCB ASSY Part Number Description Reference CX 6/6T t SCREW, 4 REW FAN MRES TO 6E TFtlMUED TO 6So- i.25. LENGTH TU6lNG CLEAR . n s-Plc 14 CCWUCTC+7 RIBBUd CMLE WH PIN-TO-PIN INERCCN

45、NECTS I ! !lll I AC POW4 cm I I AC INPUI CWNNEL 2 M 2 AK40 SUR Al PART W J5l WIRING DIAGRAM - CX 12T, 1OOV SHOW ., _,_, .,. . _ _ _,_,.” -_,. “.“_,” ,_-.- -,. 16 CCWJCTOR RIBCW CABLE ME-l PIN-TO-PIN INlERCWNfCTS AC INPUT AC POMR CCi?D _-I- AC s-PTC r L - ,wJm !iil L_-_J CH1AuOlom (XF-OCUl24-00) WRING DIAGRAM - CX lZl, 23OV SHOWN CX4 / 4T PCB Assemblies Component Side CX4 / 4T PCB A s s e m b l i e s Solder Side CX6,6T iti? J903 J904 J905 J909 J910 FUSE i4S MARKED RISK OF FIRE- 913 REPLACE WITH