Some time ago, I have bought the kit K8077 (100w subwoofer kit). Now it is assembled I have a problem during the test. The first test is OK (J2: + 15V, J3: -15V,…). When the IC’s are mounted there is still no problem.
When I flip the Mode switch to ‘ON’, the problem starts: the relais is flipping on and off and so does the light bulb in the test-jig, it goes on and off.
I have already controlled everything (I think) but I don’t find the cause of the problem. Is there somebody who knows the reason for that behaviour ? What is wrong ?
Something is drawing too much current, that is clear.
Most likely the power amp section.
If you disconnect the power transistors of the power stage, do you get the same behaviour ? If not, check power transistors and driver transistors of power stage.
I have bought the same kit, and wile testing I have the same problems (relais flippering on and off).
I disconnected the wire’s to the speakers before testing to prevent damage on the speakers in a faulty circuit.
Can that mayby couse the problems???
I bought two sets of this subwoofer kit to repair my Eltax Evolution 5.2 speaker system.
While testing the first one, I still have to build the second, I got the same problem.
I disconnected the collectors from both power transistors, and all voltages are good.
Have any of you solved the problem yet, and if so, How?
