1.download AVR630 service manual.
2.see P.73 C5 section.
3.Check driver transistors Q601-602 & R601-604.
4.check if 12V presence at section E5, IC59.
5.if no 12V,check,IC54 and related component to see if 23.5V inputted.
6.If no 23.5V, check transformer ac inputted, rectifier , fuses F505~506 and smoothing cap.
7.The thermistor P052/072 & P071/051 do not relate to Fan turning on. Fan On and off relates to CPU pin20 p.66. The thermistors only trigger dc protect when ambient temp. increases. You will know after you analyse the related schematics.
8.CPU sends a signal to make Q601-Q602 conduct to drive the fan to turn ON.
9.INPUT 12V to fan to check if it works .
No matter what model number it is, the structure is same.
1. download avr635 service manual.
2.see p.35 area C4. This is fan drive circuit.Check Q601-602(drive transistors as switches),R601-604(bias resistors to turn transistors on),R615(current limiting transistor).
3.p.29 check CPU pin20 fan out pwm waveform with an oscilloscope/logic probe/proskit MT-1236 when heat sink gets hot.
Lowering down the amp heat sink temp.
P.23 bias adjust. (Use Front-L channel as an example ) Adjust it from +23mV to +16mV. This lowers down the conduction rate of bias network so that the current flowing though collectors of Q437-Q438 is smallest, so is the thermal generation .
You need to adjust ALL channels.
------------------------------------------------------------
5.turn fan on on propose
a.find area E3.
b.find IC59, KIA7812API pin 3 or C526 positive, +ve, pin. connect fan +ve pin to pin3 or to C526 +ve pin and negative pin of fan to chassis or the amp large heat sink mounted with 7 power transistors.Same steps as previous mention. The fan will rotate slower if a current limiting resistors is connected between C526 +ve pin and fan +ve pin.
Besides, as previous mentioned, removing Q601-602, connecting C & E pin of the circuit board can also make fan rotate.
Hi!
First, you should check whether the + 12 V is present on the fan connector, between GND and one of the connectors.
If so, then you should check the fan to see if it is working.
Unfortunately, the fan control is quite complicated, it can be checked with many measurements.
Hifista.
In this case, I would start by checking the posistors (PTC).
Based on the drawing, you can tell that two of them are 100 Ohms, there is no specific information about the other two, but you need to check whether they are open or shorted.
Unfortunately, this part has been overcomplicated, the volume also matters, as well as the temperature, depending on these and the processor controls the fan speed.
You can find the fault in the way described by Ambrosia Heart.
I will first move from the simpler fault to the more complex, while he immediately dives into the thick of it.
I definitely recommend adjusting the idle current of the seven output stages, because a idle current that is higher than necessary causes a lot of heat generation.
1.Voltage and fan OK, check fan drive circuit.
2.See p.73 at C5 area. Check Q601-602 ,2SD1302, if they are OK. If don’t know how to check them, buy 2 new ones.
3.check 4 bias resistors resistances, R601-604.They make Q601-602 turn on,when receiving PWM signal sent from CPU ,IC600, pin20 on p.66.
4.check current limiting resistor resistance R615-616.
The above mentioned components give a fan drive circuit to turn fan on.
If they are ALL good, check CPU pin 20 with an oscilloscope or a logic or probe or Hz option on proskit MT-1236 multimeter. Connent the crocodile clip of either oscilloscope probe or logic probe or MT-1236 black probe to heat sink or chassis. Oscilloscope probe or logic probe or MT-1236 red probe to pin20 to see if there is a wavefrom or flash light or xxxKHz when the amp gets hot.
If no, CPU pwm inside circuit is faulty.
How to check resistances on board.
1.measure 2 pin of a resistor by an ohm meter.
2.The resistance(s) must be equal to or smaller than the marked value(s) in schematic.
3.You can also take them out of the circuit board to measure.
Alternative methods to turn fan on on propose. There are 2 options.
Read it carefully.
A.DO NOT connect the fan to fan socket, p810/809. Connect the positive pin of the fan directly to positive pin of C526 next to IC59,12V regulator, 78M12 pin3.PIN3 not PIN1, pin1 23.6V!!!!
Fan negative pin connect to large heat sink mounted with 7 pairs power transistors, (emitter followers) or the pin2 of 78M12 or negative pin of C526.
B.Connect fan to fan socket P810/809.
take out Q601-602 from circuit. Now no transistors are in the board. solder C and E pin together. This lets 12V current flow though fan via current-limiting resistor R615/616 to ground.
Check 2SD1302 datasheet on web to see which pins are C & E.
How to lower down the amp temperature caused by current amplification section.
Lower the Quiescent current of ALL channels by adjusting the idle currents of ALL channels. See p.62-63
adjust the value from +23mV to 16mV. (+23mV x 70%.) After lowering quiescent current, less heat will be generated. Amplitude of sine signal to be amplified will be, of course, smaller. i.e. less dB. This amp gives 30dB gain.
Option A highly recommended.
If you suspect Q601-Q602 are faulty, buy 2 new ones to replace them directly. Components do not cost you too much comparing labour cost of calling a tech to repair it. Replacing them does not ,however, guarantee the fan will turn on if no PWM comes from CPU pin20.
If you are just a user, connect the fan +ve pin to a current limiting resistor 2.2 ohms 1/4w then to C526 +ve pin and fan -ve pin to heat sink to make fan rotate or lowering down idle current can solve your problem. PWM coming from pin20 CPU just controls fan rotating speed.
1.download AVR630 service manual.
2.see P.73 C5 section.
3.Check driver transistors Q601-602 & R601-604.
4.check if 12V presence at section E5, IC59.
5.if no 12V,check,IC54 and related component to see if 23.5V inputted.
6.If no 23.5V, check transformer ac inputted, rectifier , fuses F505~506 and smoothing cap.
7.The thermistor P052/072 & P071/051 do not relate to Fan turning on. Fan On and off relates to CPU pin20 p.66. The thermistors only trigger dc protect when ambient temp. increases. You will know after you analyse the related schematics.
8.CPU sends a signal to make Q601-Q602 conduct to drive the fan to turn ON.
9.INPUT 12V to fan to check if it works .
0
You have this checklist for the avr635? Made a mistake in the subject
0
No matter what model number it is, the structure is same.
1. download avr635 service manual.
2.see p.35 area C4. This is fan drive circuit.Check Q601-602(drive transistors as switches),R601-604(bias resistors to turn transistors on),R615(current limiting transistor).
3.p.29 check CPU pin20 fan out pwm waveform with an oscilloscope/logic probe/proskit MT-1236 when heat sink gets hot.
Lowering down the amp heat sink temp.
P.23 bias adjust. (Use Front-L channel as an example ) Adjust it from +23mV to +16mV. This lowers down the conduction rate of bias network so that the current flowing though collectors of Q437-Q438 is smallest, so is the thermal generation .
You need to adjust ALL channels.
------------------------------------------------------------
5.turn fan on on propose
a.find area E3.
b.find IC59, KIA7812API pin 3 or C526 positive, +ve, pin. connect fan +ve pin to pin3 or to C526 +ve pin and negative pin of fan to chassis or the amp large heat sink mounted with 7 power transistors.Same steps as previous mention. The fan will rotate slower if a current limiting resistors is connected between C526 +ve pin and fan +ve pin.
Besides, as previous mentioned, removing Q601-602, connecting C & E pin of the circuit board can also make fan rotate.
0
HELLO:
SM
https://elektrotanya.com/harman_kardon_avr630_sm.pdf/download.html
0
Seems to be a avr635. In the SM i do not find anything specific. Coolingplate gets really hot, then go to standby mod
0
Hi!
First, you should check whether the + 12 V is present on the fan connector, between GND and one of the connectors.
If so, then you should check the fan to see if it is working.
Unfortunately, the fan control is quite complicated, it can be checked with many measurements.
Hifista.
0
12V is present. The fan works with a 12v battery. What measurements do you propose
0
In this case, I would start by checking the posistors (PTC).
Based on the drawing, you can tell that two of them are 100 Ohms, there is no specific information about the other two, but you need to check whether they are open or shorted.
Unfortunately, this part has been overcomplicated, the volume also matters, as well as the temperature, depending on these and the processor controls the fan speed.
You can find the fault in the way described by Ambrosia Heart.
I will first move from the simpler fault to the more complex, while he immediately dives into the thick of it.
I definitely recommend adjusting the idle current of the seven output stages, because a idle current that is higher than necessary causes a lot of heat generation.
1
1.Voltage and fan OK, check fan drive circuit.
2.See p.73 at C5 area. Check Q601-602 ,2SD1302, if they are OK. If don’t know how to check them, buy 2 new ones.
3.check 4 bias resistors resistances, R601-604.They make Q601-602 turn on,when receiving PWM signal sent from CPU ,IC600, pin20 on p.66.
4.check current limiting resistor resistance R615-616.
The above mentioned components give a fan drive circuit to turn fan on.
If they are ALL good, check CPU pin 20 with an oscilloscope or a logic or probe or Hz option on proskit MT-1236 multimeter. Connent the crocodile clip of either oscilloscope probe or logic probe or MT-1236 black probe to heat sink or chassis. Oscilloscope probe or logic probe or MT-1236 red probe to pin20 to see if there is a wavefrom or flash light or xxxKHz when the amp gets hot.
If no, CPU pwm inside circuit is faulty.
How to check resistances on board.
1.measure 2 pin of a resistor by an ohm meter.
2.The resistance(s) must be equal to or smaller than the marked value(s) in schematic.
3.You can also take them out of the circuit board to measure.
Alternative methods to turn fan on on propose. There are 2 options.
Read it carefully.
A.DO NOT connect the fan to fan socket, p810/809. Connect the positive pin of the fan directly to positive pin of C526 next to IC59,12V regulator, 78M12 pin3.PIN3 not PIN1, pin1 23.6V!!!!
Fan negative pin connect to large heat sink mounted with 7 pairs power transistors, (emitter followers) or the pin2 of 78M12 or negative pin of C526.
B.Connect fan to fan socket P810/809.
take out Q601-602 from circuit. Now no transistors are in the board. solder C and E pin together. This lets 12V current flow though fan via current-limiting resistor R615/616 to ground.
Check 2SD1302 datasheet on web to see which pins are C & E.
How to lower down the amp temperature caused by current amplification section.
Lower the Quiescent current of ALL channels by adjusting the idle currents of ALL channels. See p.62-63
adjust the value from +23mV to 16mV. (+23mV x 70%.) After lowering quiescent current, less heat will be generated. Amplitude of sine signal to be amplified will be, of course, smaller. i.e. less dB. This amp gives 30dB gain.
Option A highly recommended.
Let me know which option you use.
0
At both sides of R601 and R602 12V with +fan. At R616 0,3V with +fan. Broken transistor?
0
If you suspect Q601-Q602 are faulty, buy 2 new ones to replace them directly. Components do not cost you too much comparing labour cost of calling a tech to repair it. Replacing them does not ,however, guarantee the fan will turn on if no PWM comes from CPU pin20.
If you are just a user, connect the fan +ve pin to a current limiting resistor 2.2 ohms 1/4w then to C526 +ve pin and fan -ve pin to heat sink to make fan rotate or lowering down idle current can solve your problem. PWM coming from pin20 CPU just controls fan rotating speed.
0