Hello again
Again I need some help with this amp I have recently received.
Opening it, I found that someone had tried to repair it, without success.
There was a spark in a FET output stage, as you can see in the picture, I have extracted the two FETs, but the fet that was burned, was not the one who had the spark, it was the other, his companion.
He was also replaced an electrolytic capacitor power supply, particularly the C16.
I checked the power FETs, and more other components, and look well.
By connecting the amplifier, nothing happens, the power LED is not illuminated.
When only connect the negative and remote, to see the waveform in the legs gate Q8 and Q9 no square waveform, either in U1 output pins ...
any ideas?http://www.google.es/url?rs=rsmf&q=http://translate.google.com/toolkit?hl=eshttp://www.google.es/url?rs=rsmf&q=http://translate.google.com/manager/website/?hl=eshttp://www.google.es/url?rs=rsmf&q=http://translate.google.com/globalmarketfinder/?locale=es
Again I need some help with this amp I have recently received.
Opening it, I found that someone had tried to repair it, without success.
There was a spark in a FET output stage, as you can see in the picture, I have extracted the two FETs, but the fet that was burned, was not the one who had the spark, it was the other, his companion.
He was also replaced an electrolytic capacitor power supply, particularly the C16.
I checked the power FETs, and more other components, and look well.
By connecting the amplifier, nothing happens, the power LED is not illuminated.
When only connect the negative and remote, to see the waveform in the legs gate Q8 and Q9 no square waveform, either in U1 output pins ...
any ideas?http://www.google.es/url?rs=rsmf&q=http://translate.google.com/toolkit?hl=eshttp://www.google.es/url?rs=rsmf&q=http://translate.google.com/manager/website/?hl=eshttp://www.google.es/url?rs=rsmf&q=http://translate.google.com/globalmarketfinder/?locale=es
Attachments
If you measure the resistance between the legs of the individual output transistors in all possible combinations, do the readings for the transistors on one driver IC match the readings for the transistors on the other driver IC?
If the readings vary significantly and the output transistors are OK, you could have a bad driver IC.
If the readings vary significantly and the output transistors are OK, you could have a bad driver IC.
I have checked all the audio output stage, comparing measurements on one side and another, and I have not found significant differences.
I connected the amplifier with a car battery with a 5A fuse at B +, has been on the red LED, and turn blue, C70 has exploded ...
Rail voltage remains on the circuit..
I have a problem with the power supply ...
I connected the amplifier with a car battery with a 5A fuse at B +, has been on the red LED, and turn blue, C70 has exploded ...
Rail voltage remains on the circuit..
I have a problem with the power supply ...
Attachments
Again revised several components, replaced all FET audio output, after connecting the amplifier, red two seconds LED, blue LED lit, but the output terminals of audio, are present 40V, which soon fall to 25V ....
Nothing is heated, any fuse blows, despite having a fuse one of 5A installed in the B+ ....
something escapes my hands ...
This current can be offset voltage?
Nothing is heated, any fuse blows, despite having a fuse one of 5A installed in the B+ ....
something escapes my hands ...
This current can be offset voltage?
The two transistors that read 0 ohms have their drains connected to the positive rail. The other two have their drains connected to the source of the adjacent transistors and also to the speaker terminals.
For the two transistors that read 10k, you should read 10k between the drain and source of each of the individual transistors.
For the two transistors that read 10k, you should read 10k between the drain and source of each of the individual transistors.
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