I received this amp. The owner connected a sub with lower impedance, the amp draws current and switched off.. I want to test the amp, but its not switching on.
On the PS Driver Board is a Jumper, seems like undervoltage release. If i switch that jumper , the amp turns on. Does anybody have a diagram for this. Iam sure, that there was something in the forum, but i cant find it.
On the PS Driver Board is a Jumper, seems like undervoltage release. If i switch that jumper , the amp turns on. Does anybody have a diagram for this. Iam sure, that there was something in the forum, but i cant find it.
Attachments
Does the jumper change the voltage on any pins of the comparator on that board?
If so, which ones and how do they change?
If so, which ones and how do they change?
So, with the jumper in the correct position, I have no supply voltage, or only 0.4v. Also at pin 3 at the lm293 is 0,4v.pin 5 the same. With the jumper in the other position, I have 12v at the supply pins, pin 1 is 1.04v.
Pin 2 4.35v
Pin3 0.14v
Pin4 12v
Pin 5 0.14v
Pin6 2.55 v
Pin7 0.28v
Pin 8 supply..
Pin 2 4.35v
Pin3 0.14v
Pin4 12v
Pin 5 0.14v
Pin6 2.55 v
Pin7 0.28v
Pin 8 supply..
The circled diode is a zener with 8.2v.. The jumper is bridging this diode, and the voltage drops to 0v at the zener, and the amp switch on.
I have no diagrams that show a jumper that will control the supply voltage or one that connects to any diode.
OK, the driver board seems OK.. I will look for a diagram for the whole amp. I think, there is missing a DC from somewhere of the audio drive maybe.
