Hi!!
I bought a kenwood Excelon amplifier with the power supply blown, 8 2sk3662 fets, all blown has show in the picture.
I cant find this fets in my town so i see in this forum someone replace it with irfz44n, so i take 8 irfz48n i have over there.
Now the problem is when i apply 12v to the b+ and remite the MOSFET get very hot and the 10a power supply i use for this turn off, so i know the MOSFET are ON always, they dont turn off.
The gate resistir original comes with 10 Ohm so i replace it because are blown but nothing, the fets are on always. Change it with 100 Ohm nothing, with 50 ohms nothing again, fet are on.
So i take out the gate resistir and grounded the gate directly and the power supply keeps on and i can take measures.
The upc494 seems to be ok, it has voltages ok, and the gate drivers before the resistor (resistor go out) has about 4 volts both.
I check the output transistor and are ok. Rectifiers go out and check, are ok.
What i can check or replace??
I bought a kenwood Excelon amplifier with the power supply blown, 8 2sk3662 fets, all blown has show in the picture.
I cant find this fets in my town so i see in this forum someone replace it with irfz44n, so i take 8 irfz48n i have over there.
Now the problem is when i apply 12v to the b+ and remite the MOSFET get very hot and the 10a power supply i use for this turn off, so i know the MOSFET are ON always, they dont turn off.
The gate resistir original comes with 10 Ohm so i replace it because are blown but nothing, the fets are on always. Change it with 100 Ohm nothing, with 50 ohms nothing again, fet are on.
So i take out the gate resistir and grounded the gate directly and the power supply keeps on and i can take measures.
The upc494 seems to be ok, it has voltages ok, and the gate drivers before the resistor (resistor go out) has about 4 volts both.
I check the output transistor and are ok. Rectifiers go out and check, are ok.
What i can check or replace??
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