Basically my friend had just had his amplifier repaired (he is a bit careless)
He was placing the amplifier in the car, and basically he was giving power to the amplifier while the car was on...
I don't know what he exactly did but he is saying that he by mistake touched or overchanged the plus or negative terminals.
The amplifier fell in protect mode and is stuck there.
So basically i have a situation where no RCA or speaker cables are attached and the amplifier is still in protect mode.
The amplifier is a 2channel amplifier branded Boschmann.
Now i opened up the unit and figured out the various power supply transistors and output transistors with the other various components.
If i understood well in such situation it is most like that the output transistors are shorted.
Thus i tested with the multimeter set as diode check.
The output transistors type is BD912 and complementary BD911.
The ohmage between the legs of the transistors 1-3, 1-2, 2-3 are all in the megaohm range while regarding the voltages achieved in diode check,
between legs 1-2 and 1-3 it is 0.481v while between legs 2-3 it is 0.745v
These are the values that read for the output transistors, can anyone describe me what they mean?
I also gave a look to the power supply transistors type IRFZ24N
between legs 1-2 it is in the kohm range, between legs 1-3 it is 320ohm, while between legs 2-3 it shows 0ohm.
Can anyone give me a help what shall i do to repair it?
He was placing the amplifier in the car, and basically he was giving power to the amplifier while the car was on...
I don't know what he exactly did but he is saying that he by mistake touched or overchanged the plus or negative terminals.
The amplifier fell in protect mode and is stuck there.
So basically i have a situation where no RCA or speaker cables are attached and the amplifier is still in protect mode.
The amplifier is a 2channel amplifier branded Boschmann.
Now i opened up the unit and figured out the various power supply transistors and output transistors with the other various components.
If i understood well in such situation it is most like that the output transistors are shorted.
Thus i tested with the multimeter set as diode check.
The output transistors type is BD912 and complementary BD911.
The ohmage between the legs of the transistors 1-3, 1-2, 2-3 are all in the megaohm range while regarding the voltages achieved in diode check,
between legs 1-2 and 1-3 it is 0.481v while between legs 2-3 it is 0.745v
These are the values that read for the output transistors, can anyone describe me what they mean?
I also gave a look to the power supply transistors type IRFZ24N
between legs 1-2 it is in the kohm range, between legs 1-3 it is 320ohm, while between legs 2-3 it shows 0ohm.
Can anyone give me a help what shall i do to repair it?