Banda 4000.4

[Hexhclass]

This amp will play audio for about 3 minutes and stop,then the red LED(clip/short) will start blinking .
The manual indicates a solid blue light and a blinking red light is a short on the speaker output or wrong impedance.I
could not find any short. Any suggestions?

 

[Perry Babin]

Post a good quality photo of the component side of the entire main board and the component side of any driver boards if no one can help.

 

[Hexhclass]

I tried all channels same results

 

[Perry Babin]

If you let the amp idle (no audio) for 10 minutes, is there any heating of the heatsink?

If you let the amp idle (no audio) for 10 minutes and then try to get audio out of it, does it still play for 3 minutes?

 

[Hexhclass]

The heatsink seem to be getting warm evenly.Without audio while idling it will do the same thing but it takes a little longer to do it.

 

[Perry Babin]

If you let the amp idle (no audio) for 10 minutes and then try to get audio out of it, does it still play for 3 minutes?

 

[Hexhclass]

It will not idle for 10 minutes .If I apply a signal just before I no it’s about to shutdown it will still shutdown .
Am starting to think it is heat related.I will pull it from the heatsink.

 

[Hexhclass]

All the output FETs heating up evenly.
There is a smd thermistor in the middle of the board I remove it but no change.

 

[Perry Babin]

Have you tried to get a schematic diagram from the manufacturer?

Monitoring pin 5 on each of the driver ICs, does the voltage on that terminal change (5v down to 0v?) as the amp shuts down?

 

[Hexhclass]

All of them have -1.773v when it shuts down

 

[Perry Babin]

Have you tried to get a schematic diagram from the manufacturer?

Where was the black meter probe when you read negative voltage?

 

[Hexhclass]

I will try to get get it from them.

Black prob on main ground.I also tried RCA ground