Hello everyone.
I new on this forum and i would like to ask if someone could help me with this chinese copy of korean board.
It's arrive with all power mosfets burned also 3525 was burned, i replaced all power transistor and IC and it start to power on, but after it start to have anomalies with a sound,( only half sinus wave is out) and something strange with a power supply.
There are some measure that i take maybe someone can understand whats going on with this amp.
Measurements from central GND. Dc supply on 13.1V. Measurements without driver board.
IC 3525: IC393
Pin1: 0 V Pin9: 5.20 V ---??? Pin1: 8.3 V
Pn 2: 4.73 V Pin10: 0.05 V Pin2: 2.4 V
Pin 3: 0.01 V Pin11: 3.7 V Pin3: 4.3 V
Pin 4: 0.47 V Pin 12: 0 Pin4: 0 V
Pin 5: 1.89 V Pin 13: 9.37 V Pin5: from 2.6V and growning up Why???
Pin 6: 3.40 V Pin 14: 3.7 V Pin6: 2.37 V
Pin 7: 1.82 V Pin 15: 9.37 V Pin7: 3.5 V
Pin 8: 4.50 V Pin 16: 4.73 V Pin8: 4.7V
Also i measured optocouplers and have some strange dates: (mesures were done between pin)
Ic 303 Ic304
1-2: 52V ??? 1-2: 1.3 V
3-4: 0.2V 3-4: 1.08 V
5-6: 5.6 V 5-6: 0.24 V
7-8: 4.8V 7-8: 4.7 V
I have tooked also measurements from driver connector (without driver board, central GND as point). Seems something wrong with negative rail.
Vnn: -109.2V ?? -15: -14.57
Drv: -109.2V ?? +15: +15.00
VPP: +129V ??
Also R330 is very hot and when i try to touch it with multemeters probe i start to hear some noise from power transformer ???
I hope someone can help with this issue.
I new on this forum and i would like to ask if someone could help me with this chinese copy of korean board.
It's arrive with all power mosfets burned also 3525 was burned, i replaced all power transistor and IC and it start to power on, but after it start to have anomalies with a sound,( only half sinus wave is out) and something strange with a power supply.
There are some measure that i take maybe someone can understand whats going on with this amp.
Measurements from central GND. Dc supply on 13.1V. Measurements without driver board.
IC 3525: IC393
Pin1: 0 V Pin9: 5.20 V ---??? Pin1: 8.3 V
Pn 2: 4.73 V Pin10: 0.05 V Pin2: 2.4 V
Pin 3: 0.01 V Pin11: 3.7 V Pin3: 4.3 V
Pin 4: 0.47 V Pin 12: 0 Pin4: 0 V
Pin 5: 1.89 V Pin 13: 9.37 V Pin5: from 2.6V and growning up Why???
Pin 6: 3.40 V Pin 14: 3.7 V Pin6: 2.37 V
Pin 7: 1.82 V Pin 15: 9.37 V Pin7: 3.5 V
Pin 8: 4.50 V Pin 16: 4.73 V Pin8: 4.7V
Also i measured optocouplers and have some strange dates: (mesures were done between pin)
Ic 303 Ic304
1-2: 52V ??? 1-2: 1.3 V
3-4: 0.2V 3-4: 1.08 V
5-6: 5.6 V 5-6: 0.24 V
7-8: 4.8V 7-8: 4.7 V
I have tooked also measurements from driver connector (without driver board, central GND as point). Seems something wrong with negative rail.
Vnn: -109.2V ?? -15: -14.57
Drv: -109.2V ?? +15: +15.00
VPP: +129V ??
Also R330 is very hot and when i try to touch it with multemeters probe i start to hear some noise from power transformer ???
I hope someone can help with this issue.
Attachments
Hello everyone.
I new on this forum and i would like to ask if someone could help me with this chinese copy of korean board.
It's arrive with all power mosfets burned also 3525 was burned, i replaced all power transistor and IC and it start to power on, but after it start to have anomalies with a sound,( only half sinus wave is out) and something strange with a power supply.
There are some measure that i take maybe someone can understand whats going on with this amp.
Measurements from central GND. Dc supply on 13.1V. Measurements without driver board.
IC 3525:
Pin1: 0 V
Pn 2: 4.73 V
Pin 3: 0.01 V
Pin 4: 0.47 V
Pin 5: 1.89 V
Pin 6: 3.40 V
Pin 7: 1.82 V
Pin 8: 4.50 V
Pin9: 5.20 V ---???
Pin10: 0.05 V
Pin11: 3.7 V
Pin 12: 0
Pin 13: 9.37 V
Pin 14: 3.7 V
Pin 15: 9.37 V
Pin 16: 4.73 V
IC393:
Pin1: 8.3 V
Pin2: 2.4 V
Pin3: 4.3 V
Pin4: 0 V
Pin5: from 2.6V and growning up Why???
Pin6: 2.37 V
Pin7: 3.5 V
Pin8: 4.7V
Also i measured optocouplers and have some strange dates: (mesures were done between pin)
Ic 303
1-2: 52V ???
3-4: 0.2V
5-6: 5.6 V
7-8: 4.8V
Ic304
1-2: 1.3 V
3-4: 1.08 V
5-6: 0.24 V
7-8: 4.7 V
I have tooked also measurements from driver connector (without driver board, central GND as point). Seems something wrong with negative rail.
Vnn: -109.2V ??
Drv: -109.2V ??
VPP: +129V ??
-15: -14.57
+15: +15.00
Also R330 is very hot and when i try to touch it with multemeters probe i start to hear some noise from power transformer ???
I hope someone can help with this issue.
I new on this forum and i would like to ask if someone could help me with this chinese copy of korean board.
It's arrive with all power mosfets burned also 3525 was burned, i replaced all power transistor and IC and it start to power on, but after it start to have anomalies with a sound,( only half sinus wave is out) and something strange with a power supply.
There are some measure that i take maybe someone can understand whats going on with this amp.
Measurements from central GND. Dc supply on 13.1V. Measurements without driver board.
IC 3525:
Pin1: 0 V
Pn 2: 4.73 V
Pin 3: 0.01 V
Pin 4: 0.47 V
Pin 5: 1.89 V
Pin 6: 3.40 V
Pin 7: 1.82 V
Pin 8: 4.50 V
Pin9: 5.20 V ---???
Pin10: 0.05 V
Pin11: 3.7 V
Pin 12: 0
Pin 13: 9.37 V
Pin 14: 3.7 V
Pin 15: 9.37 V
Pin 16: 4.73 V
IC393:
Pin1: 8.3 V
Pin2: 2.4 V
Pin3: 4.3 V
Pin4: 0 V
Pin5: from 2.6V and growning up Why???
Pin6: 2.37 V
Pin7: 3.5 V
Pin8: 4.7V
Also i measured optocouplers and have some strange dates: (mesures were done between pin)
Ic 303
1-2: 52V ???
3-4: 0.2V
5-6: 5.6 V
7-8: 4.8V
Ic304
1-2: 1.3 V
3-4: 1.08 V
5-6: 0.24 V
7-8: 4.7 V
I have tooked also measurements from driver connector (without driver board, central GND as point). Seems something wrong with negative rail.
Vnn: -109.2V ??
Drv: -109.2V ??
VPP: +129V ??
-15: -14.57
+15: +15.00
Also R330 is very hot and when i try to touch it with multemeters probe i start to hear some noise from power transformer ???
I hope someone can help with this issue.
Attachments
The attached is close to what you have.
Some of the voltage need a primary ground ans some a seccondary ground. To make this easier, connect the negative speaker terminal to the primary ground. Then repost the DC voltage on pins 15 and 16 of the SG3525.
Why do you think there is a problem with the negative rail?
Some of the voltage need a primary ground ans some a seccondary ground. To make this easier, connect the negative speaker terminal to the primary ground. Then repost the DC voltage on pins 15 and 16 of the SG3525.
Why do you think there is a problem with the negative rail?
Pin 13 - 10.26V
I thinked that i have some problem with negative rail, because on driver module connector i have
VPP 129 V
VNN 109.2 V
and when i assembled all together i had on speaker out only half period wave (only positive, no negative part of wavew.) seems work half of driver...
I also dissoldered driver for check preamp, and also in ic 107 (tl072) i had same half wave... I couldn't understand what going on.
I thinked that i have some problem with negative rail, because on driver module connector i have
VPP 129 V
VNN 109.2 V
and when i assembled all together i had on speaker out only half period wave (only positive, no negative part of wavew.) seems work half of driver...
I also dissoldered driver for check preamp, and also in ic 107 (tl072) i had same half wave... I couldn't understand what going on.
Ic 107 also 106 seems identical, right now i do test with oscilloscope, IC106 seems last point audio before driver, and on PIN 5 i have a sinus wave, but on PIN 6 and 7 out I have half wave, There are only 4 elements that can disturb a signal, I would like to change C169 and C171 because Resistors seems good.
My dc supply start with 13.1 v. Absorbement actual of amplifier is 1.78Amp (without driver board)
My dc supply start with 13.1 v. Absorbement actual of amplifier is 1.78Amp (without driver board)
I wouldn't be concerned about the driver board right now. If you're getting only 1/2 of the waveform, the problem is likely on the first IC you see with that distortion.
Check the voltage across D305. Also measure the voltage drop base to emitter and collector to emitter for Q303.
The capacitors are not likely to cause that problem. If you have both positive and negative supply voltage on the op-amp with that distortion, suspect the op-amp.
Check the voltage across D305. Also measure the voltage drop base to emitter and collector to emitter for Q303.
The capacitors are not likely to cause that problem. If you have both positive and negative supply voltage on the op-amp with that distortion, suspect the op-amp.
For now i haven't zener perhabs, i do another couple of test and i attach pictures :
1. pic of audio output wave
2. pic of switching of final audio transistors. (seems some problems with driver) ? no square wave clean...
Maybe pictures can help to understand what's wrong with amplifier...
Seems work half bridge only...
1. pic of audio output wave
2. pic of switching of final audio transistors. (seems some problems with driver) ? no square wave clean...
Maybe pictures can help to understand what's wrong with amplifier...
Seems work half bridge only...
Attachments
I have on DRV and OUT perfect sine wave also without audio signal.. Maybe i do something wrong? How it possible ? i need to see square wave not sine wave ...
Which ic start oscillation fo driver board, i think we have some problem with it.. But i remember that without final audio transistor square form were perfect...could output inductors and capacitors to create this kind of problems?
Which ic start oscillation fo driver board, i think we have some problem with it.. But i remember that without final audio transistor square form were perfect...could output inductors and capacitors to create this kind of problems?
Check the solder connections on all of the large driver board transistors by moving the body of the transistor while looking at the solder connections on the back of the board.
I don't understand what you wrote. Are you saying that the output transistors have a good square wave going to the output filter inductors?
It's possible that the output filter could cause a problem. Are the legs broken on the output inductors?
If you twist the inductors, do you see a difference in the output?
There is no single part that starts the oscillation. The class D circuit is basically an unstable circuit that oscillates and all components contribute to the oscillation. That said, problems with the small capacitors on the input and feedback to the op-amp on the driver board can cause problems but I'd leave those as is except as a last resort.
I don't understand what you wrote. Are you saying that the output transistors have a good square wave going to the output filter inductors?
It's possible that the output filter could cause a problem. Are the legs broken on the output inductors?
If you twist the inductors, do you see a difference in the output?
There is no single part that starts the oscillation. The class D circuit is basically an unstable circuit that oscillates and all components contribute to the oscillation. That said, problems with the small capacitors on the input and feedback to the op-amp on the driver board can cause problems but I'd leave those as is except as a last resort.
So, i dessoldered all finals audio mosfets, but i haven't correct oscillation, i think driver board has a problem o something go shut down oscillation.
I saw in you manual what kind of signals i need to have on driver board connector, but nothing of similar right now. As you wrote in you book, this kind of amplifier has a lot of problems. It's first time when i don't understand whats going on. Voltage is correct, audio signal is correct, why this board couldn't start with correct oscillation? Tomorrow i'll try to check all schematics, i need to finish this amplifier. Thank you a lot for you advises!!!
I saw in you manual what kind of signals i need to have on driver board connector, but nothing of similar right now. As you wrote in you book, this kind of amplifier has a lot of problems. It's first time when i don't understand whats going on. Voltage is correct, audio signal is correct, why this board couldn't start with correct oscillation? Tomorrow i'll try to check all schematics, i need to finish this amplifier. Thank you a lot for you advises!!!