portable pa hack gone wrong!

[KJ6EAD]

The silk screen labeling suggests that the power amplifier is being supplied ±15V and there's a label for -7.5V.

 

[newjazz]

Notice, the red leds indicate mute, sub limit, and top limit! Don't know if this information will help give me an idea about what I destroyed!
The bottom right side of the board

is the spot where the negative speaker wire touched the small heat sink for the voltage regulators.

 

[newjazz]

View attachment 112033

Wouldnt i still need a buck converter to get my ebike battery from 48v to 15v?.....also, i would need some type of regulator to keep the voltage to the board constant, no?
Would you suggest taking out the 2 voltage regulators and the amplifier IC to test them or, should I wait until I get the replacement?

 

[KJ6EAD]

What are the numbers on the parts you're calling voltage regulators?

I'm also seeing another silkscreen marking of +54V. It would be nice if I could see everything.

 

[newjazz]

What are the numbers on the parts you're calling voltage regulators?

"7915A" and "L78515CV"

 

[KJ6EAD]

Those are linear regulators for ±15V. They may have used a switcher to develop 54V then fed that to the linears but I can't tell without seeing everything and making a few measurements. That -7.5V tag still has me curious of course.

 

[newjazz]

Those are linear regulators for ±15V. They may have used a switcher to develop 54V then fed that to the linears but I can't tell without seeing evdrything and making a few measurements. That -7.5V tag still has me curious of course.

Here is a pic....