LEM-P1000-pwr-sm 维修电路原理图.pdf

1 1 1 1 1 J J J J JCODE : 277320Index & WarningsSoldering point.Male connector.Female connector.M/F faston connector.Test point.Supply voltage.Logic supply ground.Analog supply ground.Signal ground.Chassis ground.Flag joined with one or more flags with the same signal name inscribed.GENERALMUSIC S.p.A. Sales Division: 47048 S.Giovanni in Marignano (RN) ITALY - Via delle Rose, 12 - tel. 0541/959511 - tlx 550555 GMUSIC I - fax 0541/957404Technical Specifications, Test Procedures & Adjustments2NoticeService must be carried out by qualified personnel only.Any tampering carried out by unqualified personnel during the guarantee period will forfeit the right to guarantee.For a correct operation of the instrument, after having switched off, be careful to wait at least 3 seconds before switching on again.To improve the devices specifications, the schematic diagrams may be subject to change without prior notice.Schematic NotesAll components marked by this symbol have special safety characteristics, when replacing any of these components use only manufacturers specified parts.The () micro symbol of capacitance value is substituted by U. The () omega symbol of resistance value is substituted by E. The electrolytic capacitors are 25Vdc rated voltage unless otherwise specified. All resistors are 1/8W unless otherwise specified.ATTENTIONObserve precautions when handlingelectrostatic sensitive devicesSERVICE MANUALSchematic DiagramsBlock Diagram5Protections, Fuse, Supply, Display, Sockets, Inputs Boards78Part List, LayoutDriver & Power Boards6RadioFans.CN 收音机爱 好者资料库J J J J J 2 2 2 2 2TECHNICAL SPECIFICATIONSTECHNICAL SPECIFICATIONSTECHNICAL SPECIFICATIONSTECHNICAL SPECIFICATIONSTECHNICAL SPECIFICATIONSDimensions:(WxHxD)483x88x445mm (2U)Weight:16KgPower Requirements:(230Vac15% 50/60Hz)1000VA(115Vac15% 50/60Hz)1000VAOutput Power:(4 stereo/parallel)2x 500Watts(8 stereo/parallel)2x 350Watts(8 bridge)1000Watts(16 bridge)700WattsMax. Undistorted Out: (4 stereo/parallel)126Vpp(8 stereo/parallel)149Vpp(8 bridge)250VppInput Sensitivity:(constant sensitivity)0.775Vrms (0dB)(constant gain)2.25Vrms (+9.2dB)Input Impedance:(balanced)30K(unbalanced)15KVoltage Gain:(constant sensitivity)350.5dB(constant gain)260.5dBSlew Rate:25V/SDamping Factor:(4 stereo/parallel)400(8 stereo/parallel)800Frequency Response(-0.2dB)20Hz20KHzat Full Power:(-3dB)10Hz60KHzIMD:(SMPTE 60Hz/7KHz 4:1)0.1%THD:(THD+N)95dBCrosstalk:(1KHz)70dBTEST PROCEDURES & ADJUSTMENTSTEST PROCEDURES & ADJUSTMENTSTEST PROCEDURES & ADJUSTMENTSTEST PROCEDURES & ADJUSTMENTSTEST PROCEDURES & ADJUSTMENTSPrecautionPrecautionPrecautionPrecautionPrecaution To prevent short circuit during any test, the oscilloscope must bethe oscilloscope must bethe oscilloscope must bethe oscilloscope must bethe oscilloscope must beEARTH insulatedEARTH insulatedEARTH insulatedEARTH insulatedEARTH insulated, this occurs because some test require to connect itsprobe to the amplifier output, non-compliance may cause damages tooscilloscope inputs circuitry. Before removing or installing any modules and connectors, disconnectdisconnectdisconnectdisconnectdisconnectthe amplifier from AC MAINSthe amplifier from AC MAINSthe amplifier from AC MAINSthe amplifier from AC MAINSthe amplifier from AC MAINS and measure the DC supply voltagesacross each of the power suppliy capacitors. If your measurement on anyof the caps is greater than 10Vdc, connect a 100 100W resistor acrossthe applicable caps to discharge them for your safety. Remember toremove the discharge resistor immediately after discharging caps. Do notDo notDo notDo notDo notpower up the amplifier with the discharge resistor connectedpower up the amplifier with the discharge resistor connectedpower up the amplifier with the discharge resistor connectedpower up the amplifier with the discharge resistor connectedpower up the amplifier with the discharge resistor connected. Read these notes entirely before proceeding to any operation. Thesenotes are not comprehensive of all damages that possibly occur, butincludes some specifically advices, checks and adjustments relative tothis amplifier.RemarksRemarksRemarksRemarksRemarks The output coupled transistors TR6-TR11 (MJ15022/B) and TR16-TR22(MJ15023/B) are factory selected on VBE and VBREAKDOWN (IEC0-6.6mA atV(BR)CE0=11V for NPN and IEC06.6mA at V(BR)CE0=-11V for PNP)The selection is marked by a red digit (from 0 to B) representative of VBEforward voltage categories, these are subdivided in 12 steps of 30mVeach.Only selected transistors must be used when replacing TR6-TR11 orOnly selected transistors must be used when replacing TR6-TR11 orOnly selected transistors must be used when replacing TR6-TR11 orOnly selected transistors must be used when replacing TR6-TR11 orOnly selected transistors must be used when replacing TR6-TR11 orTR16-TR22 and every coupled transistors must have the same digit.TR16-TR22 and every coupled transistors must have the same digit.TR16-TR22 and every coupled transistors must have the same digit.TR16-TR22 and every coupled transistors must have the same digit.TR16-TR22 and every coupled transistors must have the same digit. The power supply utilizes a dual bipolar DC rail configuration with low andhigh voltages; one positive and one negative low rail (+/-Vcc1) and onepositive and one negative high rail (+/-Vcc2).Visual CheckVisual CheckVisual CheckVisual CheckVisual Check Use compressed air to clear dust in the amplifier chassis. Before proceed to supply the amplifier check visually the internal assem-bly, if appears an evident damage find the most possible reasons thatcause it. Check the wiring cables for possible interruptions or shorts. If the damage has burnt a printed circuit board dont try to repair it, re-place with a new one.Test InstrumentTest InstrumentTest InstrumentTest InstrumentTest Instrument Audio Generator Dual Trace Oscilloscope Digital Multimeter 2 2000W, 4 1000W, 8 1000W, 100 100W resistors Variac Temperature MeterSetupSetupSetupSetupSetup Connect the Variac between the PROTECTION board and the TF1 andTF2 transformers and set it at zero voltage. Set the amplifier in STEREO MODE and turn full clockwise the LEVELpotentiometers. Connect the audio generator to the channel inputs and set it to 1KHz775mVRMS (0dB) sinusoidal signal. Insert the temperature meter through the IC1 interstice located at centreof heatsink. The procedures that follow must be executed subsequently in the orderspecified.Supply CheckSupply CheckSupply CheckSupply CheckSupply Check Remove the transformer secondary fuses (located on FUSE board), setthe Variac to the nominal mains voltage, check with the Multimeter thephase opposition between the secondaries of the two transformers (F1-F2,F3-F4), if not, verify the primary connections (T1T4 on ProtectionsBoard). Verify the AC supply voltages:F1-F2=722VacF3-F4=1283Vac. Re-set the Variac at zero voltage, turn off the amplifier and put the fusesback on its holders. Connect the oscilloscope probes CH1/2 to the channel outputs, set bothto 20V/div. 200S/div. Set up the Variac slowly monitoring the Outputs with the oscilloscopeCH1/2 connected, it should display the sinusoidal input signal amplifiedwith no distortions, if a distortion occur check the Driver and the PowerBoards as suggested in the ADVICES section. If the protection trips, turn off the amplifier, wait some minutes and dis-connect the supplies from the outputs modules (CN1 - CN2 - CN7 - CN8on POWER boards), continue to check the supplies. CAUTION: Before re-connecting the output modules to the supplies,CAUTION: Before re-connecting the output modules to the supplies,CAUTION: Before re-connecting the output modules to the supplies,CAUTION: Before re-connecting the output modules to the supplies,CAUTION: Before re-connecting the output modules to the supplies,you must have the capacitors discharged for your safety: connect ayou must have the capacitors discharged for your safety: connect ayou must have the capacitors discharged for your safety: connect ayou must have the capacitors discharged for your safety: connect ayou must have the capacitors discharged for your safety: connect a100100100100100 100W resistor across the caps and remove the resistor just 100W resistor across the caps and remove the resistor just 100W resistor across the caps and remove the resistor just 100W resistor across the caps and remove the resistor just 100W resistor across the caps and remove the resistor justafter they are discharged.after they are discharged.after they are discharged.after they are discharged.after they are discharged. Finally verify the DC supplies on Supply Board:CN6 (+Vcc2)=+89.52VdcCN8 (+Vcc1)=+501.5VdcCN7 (-Vcc1)=-501.5VdcCN2 (-Vcc2)=-89.52Vdcon Protections Board:CN2 pin3=+271VdcCN3 pin3=-271VdcCN1 pin4-5-6=+13.81VdcCN1 pin1-2-3=-13.81Vdc If one or more voltages dont correspond, check the rectifiers, capacitorsand transformers disconnecting them from circuitry, refer to schematics.Channels CheckChannels CheckChannels CheckChannels CheckChannels Check The channel A is facing the front and channel B the rear of the chassis. These procedures are intended for one channel at a time, repeat theseoperation for the other channel. Verify, with the Multimeter, the insulation between the heatsink and thetransistors collectors. SETUP:SETUP:SETUP:SETUP:SETUP:Connect the CH1 scope GND clip to CN5 (GND terminal).Connect the CH1 probe tip to CN6 (AMP output).Connect the CH2 probe tip to D2 cathode on POWER board.Set the LEVEL potentiometers full clockwise.The load resistor is disconnected. INITIAL TEST:INITIAL TEST:INITIAL TEST:INITIAL TEST:INITIAL TEST:Increase slowly the Variac. The channel output signals must be symmetri-cal respect the GND without visible distortion and oscillation as shown inFig.1 Trace A. If there is a distortion read the section ADVICES andproceed to check the other channel.Verify that, when the heatsink temperature is less 50c, the cooling fanFig. 1Fig. 1Fig. 1Fig. 1Fig. 1Trace B (20V/div.)Trace A (20V/div.)Trace C (20V/div.)RadioFans.CN 收音机爱 好者资料库3 3 3 3 3 J J J J Jvoltage must be between 12 and 16V. HIGH RAIL CHECK:HIGH RAIL CHECK:HIGH RAIL CHECK:HIGH RAIL CHECK:HIGH RAIL CHECK:When the output signal (Positive half-wave) is less than 44Vp the voltageon D2 cathode must remain constant at 50V, when the output signalexceeds 44Vp the voltage must follow the output signal with 6V offset(see Fig.1 Trace B), to check the negative high rail connect the probe toD18 anode (see Fig.1 Trace C).Connect the 4 1000W load on the output and repeat the INITIAL andHIGH RAIL checks.Check the signal clipping, it must occur at 1305Vpp (see Fig.2 TraceABC). SIGNAL/CLIP SENSOR CHECK:SIGNAL/CLIP SENSOR CHECK:SIGNAL/CLIP SENSOR CHECK:SIGNAL/CLIP SENSOR CHECK:SIGNAL/CLIP SENSOR CHECK:Set the LEVEL pot to minimum, set the scope timebase at 1V/div. 200S/div., then increase the level and check the SIGNAL/CLIP led activity: itmust turn on (green light) when the amplifier output is higher than 5Vpp.Set the scope at 50V/div. and increase the level, check the led: it mustchange from green to red colour when the amplifier output signal clip. CURRENT AND SHORT CIRCUIT SENSOR CHECK:CURRENT AND SHORT CIRCUIT SENSOR CHECK:CURRENT AND SHORT CIRCUIT SENSOR CHECK:CURRENT AND SHORT CIRCUIT SENSOR CHECK:CURRENT AND SHORT CIRCUIT SENSOR CHECK:Set the CH2 sensitivity to 0.5V/div., connect the scope CH1, GND clip atCN6 (AMP output) and the probe tip at CN5 (GND terminal), CH2 probetip alternatively on TR6, TR11 (NPN) and TR16, TR22 (PNP) emitters.Set the generator to have approx. 1Vp on the emitters: their differencemust be less than 10% one each other (see Fig.3 Trace A). The NPN orPNP transistors out of tolerance must be replaced with a new selectedpair.Connect a 2 2000W load. Connect the CH1 probe tip on TR16 emitterand the CH2 probe tip on TR11 emitter. Increase the input signal, theoutput current limiter must keep the emitter voltages (both half channel) at1.2Vp approx. (see Fig.3 Trace B).Temporarily short the amplifier output: the current limiter must keep theemitter voltages (both half channel) at 0.7Vp (see Fig.3 Trace C). COOLING FAN & PROTECTION CHECK:COOLING FAN & PROTECTION CHECK:COOLING FAN & PROTECTION CHECK:COOLING FAN & PROTECTION CHECK:COOLING FAN & PROTECTION CHECK:Short circuit pins 11 and 12 of OC1 on Driver board, the fan must run atmax. speed (2023Vdc on its tips).Short circuit pins 9 and 10 of OC1 on the same board, the PROTECT ledmust turn on immediately, the fan must run at max. speed. The PROTECTled of the other channel must also turn on after 2 Sec. and the relay mustdisconnect the transformers from the mains.Remove the short circuit, after 3 Sec. both PROTECT leds must turn offand the relay must re-connect the transformers to the mains.Temporarily short the emitter and the collector of TR7 (Driver board) thePROTECT led must turn on and the relay must disconnect the transform-ers from the mains.Turn off the amplifier to reset it, wait a minute to let the supply capsdischarged. OFFSET SENSOR CHECK:OFFSET SENSOR CHECK:OFFSET SENSOR CHECK:OFFSET SENSOR CHECK:OFFSET SENSOR CHECK:Set the Variac to zero voltage output, disconnect the amplifier load andthe supply connection to the Power board (CN1,2,7,8), turn on the ampli-fier, connect temporarily (by means of a suitable conductor wire) CN6 to+15Vdc, the PROTECT led must turn on immediately; the fan must run atmaximum speed).Reset the protection turning off the amplifier, turn it on again, connecttemporarily (by means of a suitable conductor wire) CN6 to -15Vdc, theled PROTECT must turn on again. SOA ADJUSTMENT:SOA ADJUSTMENT:SOA ADJUSTMENT:SOA ADJUSTMENT:SOA ADJUSTMENT:Set the scope sensitivity at 5V/div. (both channels) and connect the CH1probe on D12 cathode and the CH2 probe on D11 anode on Driver board,check the voltage across D12 and D11 zener diodes: it must be14.80.1V; increasing 10dB the generator level this voltage does notdecrease more than 0.5V.Connect the 4 1000W load, set the scope sensitivity at 2V/div. andconnect the CH1 probe tip at R43 side CN3 and the CH2 probe tip at R36side CN2. Decrease the signal level until two sinusoid appear on thescope as shown in Fig 4 Trace AB.Their max. amplitude must be 5.5Vp (the outer) and 1.5Vp (the inner) asshown in Fig 5 Trace A,B; increasing a bit the generator signal, the innersinusoid must produce spikes on its peaks as shown in Fig 5 Trace A,B.Connect the 2 1000W load, set the scope sensitivity at 1V/div. (bothchannels) and connect its probes to the collectors of TR8 (CH1) andTR11 (CH2) on Driver Board.Disconnect the fan; wait until the temperature is 90C (require someminutes) then decrease the input to zero.Adjust the trimmers R20 and R40, until the scope traces go respectivelyat -2.2Vdc and +2.3Vdc; turn on the cooling fan and wait until the tem-perature goes down to 80C; then turn it off.Fig. 2Fig. 2Fig. 2Fig. 2Fig. 2Fig. 3Fig. 3Fig. 3Fig. 3Fig. 3Trace A (0.5V/div.)Trace B (0.5V/div.)Trace C (0.5V/div.)Fig. 5