Got one of these to repair and need some advice please.
Basically it's blowing the two input 2AT fuses after the transformer on power up.
I upped them to 3.15A but they also blew.
The transformer output is ok and the speaker reads 4 ohms in circuit.
As you can see the board is a bit burned at the power transistors (TIP137 & TIP 132). One of them is reading 1ohm across two of its pins. The three serial diodes look ok.
I haven't been able to find a circuit for this amp online. Anybody got one?
Obviously I suspect one of the power transistors but I'm reluctant to take them out as the board is old and burned in that area and once I go at it I'm probably only going to get one chance before the tracks start lifting.
So I'd be thankfull for any advice on which components to lift and check first. And I'd be a bit rusty on checking the power transistors, in or out of circuit, if anybody has a good guide.
Thanks.
Basically it's blowing the two input 2AT fuses after the transformer on power up.
I upped them to 3.15A but they also blew.
The transformer output is ok and the speaker reads 4 ohms in circuit.
As you can see the board is a bit burned at the power transistors (TIP137 & TIP 132). One of them is reading 1ohm across two of its pins. The three serial diodes look ok.
I haven't been able to find a circuit for this amp online. Anybody got one?
Obviously I suspect one of the power transistors but I'm reluctant to take them out as the board is old and burned in that area and once I go at it I'm probably only going to get one chance before the tracks start lifting.
So I'd be thankfull for any advice on which components to lift and check first. And I'd be a bit rusty on checking the power transistors, in or out of circuit, if anybody has a good guide.
Thanks.
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