General_Music_LEM_Procon_Series_Service_Manual电路图.pdf

1 1 1 1 1 Index Soldering point. Male connector. Female connector. M/F faston connector. Test point. Supply voltage.Logic supply ground. Analog supply ground. Chassis ground. Earth ground. Flag joined with one or more flags GENERALMUSIC S.p.A. Sales Division: 47842 S.Giovanni in Marignano (RN) ITALY - Via delle Rose, 12 Phone +39(0)541/959511 - Fax +39(0)541/957404 - Internet: PROCON 400 Test Procedure2 PROCON 750 Test Procedure2 PROCON 950 Test Procedure 4 4PROCON 1500 Test Procedure 5 PROCON 1250 Test Procedure Spare Part List 3 PROCON 1100 Test Procedure PROCON 400 Schematic PROCON 750 Schematic PROCON 950 Schematic PROCON 1500 Schematic PROCON 1250 Schematic PROCON 1100 Schematic 3 6 9 10 11 7 8 with the same signal name inscribed. ATTENTIONObserve precautions when handling electrostatic sensitive devices. Notice Service 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. All 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. All switches shown in the OFF position. All DC voltages measured to ground with a voltmeter 20KOhm/V. ? SERVICE MANUAL code 270266 RadioFans.CN 收音机爱 好者资料库 2 2 2 2 2 PROCON400 - Test procedures andPROCON400 - Test procedures andPROCON400 - Test procedures andPROCON400 - Test procedures andPROCON400 - Test procedures and adjustmentsadjustmentsadjustmentsadjustmentsadjustments PRECAUTIONPRECAUTIONPRECAUTIONPRECAUTIONPRECAUTION To prevent short circuit during any test, the oscilloscope must be EARTH INSULATED, this occurs because some test require to connect its probe to the amplifier output, non-compliance may cause damages to oscilloscope inputs circuitry. Before removing or installing any modules and connectors, disconnect the amplifier from AC MAINS and measure the DC supply voltages across each of the power supply capacitors. If your measurement on any of the caps is greater than 10Vdc, connect a 100E 30W resistor across the applicable caps to discharge them for your safety. Remember to remove the discharge resistor immediately after discharging caps. Do not power up the amplifier with the discharge resistor connected. Do not check the amplifier with the speakers connected use the appropriate load resistors only. BE CAREFUL increasing the Variac you must not exceed the nominal mains voltage plus its tolerance (see specifications) any upper voltage can be cause of damage. 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 assembly, if appears an evident damage find the most possible reasons that cause it. Check the wiring cables for possible interruptions or shorts. If the damage has burnt a printed circuit board dont try to repair it, replace with a new one. TESTING GEARTESTING GEARTESTING GEARTESTING GEARTESTING GEAR Audio Generator Dual Trace Oscilloscope Digital Multimeter 4E 300W, 8E 200W, 100E 30W resistors Variac SETUPSETUPSETUPSETUPSETUP Connect the Variac between the Mains and the amplifier and set it at zero voltage. Turn full counter-clockwise the LEVEL potentiometers. Connect the audio generator to the channel inputs and set it to 1KHz 775mVrms (0dBm) sinusoidal signal. Connect the two scope traces to the amplifier outputs, before the relay, and set them in DC at 20V/div. 2mS/div. SUPPLY CHECKSUPPLY CHECKSUPPLY CHECKSUPPLY CHECKSUPPLY CHECK Verify with the Multimeter the insulation between the heatsinks and all transistor collectors mounted on them; placing the multimeter tips between the screw heads and the collector pins you can exclude an erroneus reading due to the insulation of the heatsink anodization. Verify with the Multimeter the NTC (RT1 or RT2) and R122 or R222 paralleled resistor value, it must be about 1.17K (at 25c). Turn on the Amplifier. Remove the transformer secondary fuses, set the Variac to the nominal mains voltage, check with the Multimeter the AC supply voltages: F1-F2 = 282Vac. F3-F4 = 858Vac. Re-set the Variac at zero voltage, turn off the amplifier and put the fuses back on its holders. Set up the Variac slowly monitoring the oscilloscope screen, it should display no signal; if you notice a DC voltage or a protection trips check the amplifier as suggested in the ADVICES section. As soon as the +12VF supply circuit reaches its nominal value, all cooling fans run at their minimum and the speaker output relay (J401) switches. When the Variac ac voltage reaches the nominal voltage verify the DC supplies as follow: +VCC = +575Vdc -VCC = -575Vdc U101 pin 8 = +151Vdc U101 pin 4 = -151Vdc U401 pin 3 = +121Vdc If one or more voltages dont correspond, check the rectifiers, capacitors and transformers disconnecting them from circuitry. CHANNEL CHECKCHANNEL CHECKCHANNEL CHECKCHANNEL CHECKCHANNEL CHECK Be sure you have disconnected the load resistor. Increasing the input signal also the output signal raise accordingly, it must be symmetrical without visible distortion or oscillation as shown in figure (note: the figure is representative dont refer to the levels displayed). If there is a distortion read the section ADVICES. When the input signal exceeds -18dBm (8Vpp on output) the SIGNAL led lights and the fan turns at its maximum speed. Firstly you must check the channel without load, afterwards you must repeat the check with the loads attached, the following table reports the approx. maximum level obtainable with this amplifier: out level in level no load 110Vpp +4.5dB 1CH 8E 104Vpp +4dB 1CH 4E 92Vpp +3dB 2CH 8E 90Vpp +3dB 2CH 4E 80Vpp +2dB CLIP LED ADJUSTMENTCLIP LED ADJUSTMENTCLIP LED ADJUSTMENTCLIP LED ADJUSTMENTCLIP LED ADJUSTMENT Check if the clip led lights at approx. 0dBm on input level, if necessary adjust the trimmer W301 and W302 on display board. OFFSET ADJUSTMENTOFFSET ADJUSTMENTOFFSET ADJUSTMENTOFFSET ADJUSTMENTOFFSET ADJUSTMENT Set the input level at minimum (no signal), the output dc offset voltage must be within 20mV, if necessary adjust the W201 (CH1) or W201 (CH2) trimmers to be within this threshold. BIAS ADJUSTMENTBIAS ADJUSTMENTBIAS ADJUSTMENTBIAS ADJUSTMENTBIAS ADJUSTMENT No bias adjustment is necessary for this amplifier circuitry. ADVICESADVICESADVICESADVICESADVICES If you have determinate that the problem is a short on a rail, you must check the output transistors. To determine which transistor devices are bad, use a soldering iron to lift one leg of each emitter pin and measure the emitter- collector resistance on each device. Unsolder and lift one leg of each base pin and check the base-collector resistance of each transistor and replace any that measure as a short. If all the transistors are OK, unsolder and lift one leg of each diode and check them. Check the circuit board for open foil traces. Use the Multimeter as Ohm-meter to check the resistors, particularly the base and emitter resistors of damaged transis- tor. If the input sinewave appears to be distorted during the negative cycle, you can assume that the problem is located somewhere in the circuitry of the positive rail. If the positive cycle appears distorted, you can assume that the problem is in the circuitry of the negative rail. The dc voltages printed on the schematics are measured with the amplifier in steady state without input signal and nominal mains voltage supply, it can be useful to localize a damage. FIGURESFIGURESFIGURESFIGURESFIGURES PROCON750 - Test procedures andPROCON750 - Test procedures andPROCON750 - Test procedures andPROCON750 - Test procedures andPROCON750 - Test procedures and adjustmentsadjustmentsadjustmentsadjustmentsadjustments PRECAUTIONPRECAUTIONPRECAUTIONPRECAUTIONPRECAUTION To prevent short circuit during any test, the oscilloscope must be EARTH INSULATED, this occurs because some test require to connect its probe to the amplifier output, non-compliance may cause damages to oscilloscope inputs circuitry. Before removing or installing any modules and connectors, disconnect the amplifier from AC MAINS and measure the DC supply voltages across each of the power supply capacitors. If your measurement on any of the caps is greater than 10Vdc, connect a 100E 60W resistor across the applicable caps to discharge them for your safety. Remember to remove the discharge resistor immediately after discharging caps. Do not power up the amplifier with the discharge resistor connected. Do not check the amplifier with the speakers connected use the appropriate load resistors only. BE CAREFUL increasing the Variac you must not exceed the nominal mains voltage plus its tolerance (see specifications) any upper voltage can be cause of damage. 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 assembly, if appears an evident damage find the most possible reasons that cause it. Check the wiring cables for possible interruptions or shorts. If the damage has burnt a printed circuit board dont try to repair it, replace with a new one. TESTING GEARTESTING GEARTESTING GEARTESTING GEARTESTING GEAR Audio Generator Dual Trace Oscilloscope Digital Multimeter 4E 500W, 8E 300W, 100E 60W resistors Variac SETUPSETUPSETUPSETUPSETUP Connect the Variac between the Mains and the amplifier and set it at zero voltage. Turn full counter-clockwise the LEVEL potentiometers. Connect the audio generator to the channel inputs and set it to 1KHz 775mVrms (0dB) sinusoidal signal. Connect the two scope traces to the amplifier outputs, before the relay, and set them in DC at 20V/div. 2mS/div. SUPPLY CHECKSUPPLY CHECKSUPPLY CHECKSUPPLY CHECKSUPPLY CHECK Verify with the Multimeter the insulation between the heatsinks and all transistor collectors mounted on them; placing the multimeter tips between the screw heads and the collector pins you can exclude an erroneus reading due to the insulation of the heatsink anodization. Verify with the Multimeter the NTC (RT1 or RT2) and R122 or R222 paralleled resistor value, it must be about 1.17K (at 25c). Turn on the Amplifier. Remove the transformer secondary fuses, set the Variac to the nominal mains voltage, check with the Multimeter the AC supply voltages: F1-F2 = 282Vac. F3-F4 = 10410Vac. Re-set the Variac at zero voltage, turn off the amplifier and put the fuses back on its holders. Set up the Variac slowly monitoring the oscilloscope screen, it should display no signal; if you notice a DC voltage or a protection trips check the amplifier as suggested in the ADVICES section. As soon as the +12VF supply circuit reaches its nominal value, all cooling fans run at their minimum and the speaker output relay (J401) switches. When the Variac ac voltage reaches the nominal voltage verify the DC supplies as follow: +VCC = +755Vdc -VCC = -755Vdc U101 pin 8 = +151Vdc U101 pin 4 = -151Vdc U401 pin 3 = +121Vdc If one or more voltages dont correspond, check the rectifiers, capacitors and transformers disconnecting them from circuitry. CHANNEL CHECKCHANNEL CHECKCHANNEL CHECKCHANNEL CHECKCHANNEL CHECK Be sure you have disconnected the load resistor. Increasing the input signal also the output signal raise accordingly, it must be symmetrical without visible distortion or oscillation as shown in figure (note: the figure is representative dont refer to the levels displayed). If there is a distortion read the section ADVICES. When the input signal exceeds -18dBm (8Vpp on output) the SIGNAL led lights and the fan turns at its maximum speed. Firstly you must check the channel without load, afterwards you must repeat the check with the loads attached, the following table reports the approx. maximum level obtainable with this amplifier: out level in level no load 148Vpp +7dBm 1CH 8E 128Vpp +5.5dBm 1CH 4E 120Vpp +4.5dBm 2CH 8E 120Vpp +5dBm 2CH 4E 104Vpp +4dBm CLIP LED ADJUSTMENTCLIP LED ADJUSTMENTCLIP LED ADJUSTMENTCLIP LED ADJUSTMENTCLIP LED ADJUSTMENT Check if the clip led lights at approx. 0dBm on input level, if necessary adjust the trimmer W301 and W302 on display board. OFFSET ADJUSTMENTOFFSET ADJUSTMENTOFFSET ADJUSTMENTOFFSET ADJUSTMENTOFFSET ADJUSTMENT Set the input level at minimum (no signal), the output dc offset voltage must be within 20mV, if necessary adjust the W201 (CH1) or W201 (CH2) trimmers to be within this threshold. BIAS ADJUSTMENTBIAS ADJUSTMENTBIAS ADJUSTMENTBIAS ADJUSTMENTBIAS ADJUSTMENT No bias adjustment is necessary for this amplifier circuitry. ADVICESADVICESADVICESADVICESADVICES If you have determinate that the problem is a short on a rail, you must check the output transistors. To determine which transistor devices are bad, use a soldering iron to lift one leg of each emitter pin and measure the emitter- collector resistance on each device. Unsolder and lift one leg of each base pin and check the base-collector resistance of each transistor and replace any that measure as a short. If all the transistors are OK, unsolder and lift one leg of each diode and check them. Check the circuit board for open foil traces. Use the Multimeter as Ohm-meter to check the resistors, particularly the base and emitter resistors of damaged transis- tor. If the input sinewave appears to be distorted during the negative cycle, you can assume that the problem is located somewhere in the circuitry of the positive rail. If the positive cycle appears distorted, you can assume that the problem is in the circuitry of the negative rail. The dc voltages printed on the schematics are measured with the amplifier in steady state without input signal and nominal mains voltage supply, it can be useful to localize a damage. FIGURESFIGURESFIGURESFIGURESFIGURES RadioFans.CN 收音机爱 好者资料库 3 3 3 3 3 PROCON950 - Test procedures andPROCON950 - Test procedures andPROCON950 - Test procedures andPROCON950 - Test procedures andPROCON950 - Test procedures and adjustmentsadjustmentsadjustmentsadjustmentsadjustments PRECAUTIONPRECAUTIONPRECAUTIONPRECAUTIONPRECAUTION To prevent short circuit during any test, the oscilloscope must be EARTH INSULATED, this occurs because some test require to connect its probe to the amplifier output, non-compliance may cause damages to oscill