K8081

I have the K8081 Power Amplifier and i have some problems with it.
First of all: When i turned on the first time i noticed that i have confused the two transistors.
What followed was a little firework… The resistor R42 and transistor T4 were damaged, the resistor R16 was completely burned up.

So i started to remove every prefabricated part and then checked/replaced them. Then i put a sinusoidal signal on it and the oscilloscope showed me the signal with an amplification of 200. But only in one way. So i looked for the mistake and found it. The transistor T4 was damaed, i forgot to replace him.

Next time i turned on, both high resistances R42/R43 started to smoke. So i checked all of the components again and replaced R42/R43. RV1 is still turned low.
Then it started to smoke again.

So where is the problem now? I can´t imagine any mistake.

Best regards

Dj Wooks

When the power transistors have been swapped accidentally, we recommend to replace all semiconductors of the power amplifier section (transistors and diodes).
If the problem persists, you can return your kit for inspection to:

Velleman Projects Tech. Dept.
Legen Heirweg 33
9890 Gavere
Belgium