A speaker that can reproduce high frequencies isn't a good choice tor determining the condition of a class D amp. Use a subwoofer.
Is the noise in the speaker like this one?
http://www.bcae1.com/temp/cooleditmixedoscillator01.wav
Is that the thermal protect LED?
According to your ON numbers, that LED shouldn't be on. If it is on, I'd expect it to be barely on.
Is the noise in the speaker like this one?
http://www.bcae1.com/temp/cooleditmixedoscillator01.wav
Is that the thermal protect LED?
According to your ON numbers, that LED shouldn't be on. If it is on, I'd expect it to be barely on.
The protect not the thermal led is only on when there is b+ and ground hooked up. When you apply the remote the protect led goes out and the power light comes on.
I need the DC voltage on the inputs to comparator 3 and the output (pin 14) when the LED is on (no remote).
Re #63:
Would the noise be audible through a subwoofer?
Can you put pressure on any of the components and make the noise change like when you flex the board?
Would the noise be audible through a subwoofer?
Can you put pressure on any of the components and make the noise change like when you flex the board?
While pressing on the board with a plastic screwdriver handle I pressed on the u4 daughter board and the amp went into protect and wont come back out.
Is the U4 board a plug-in or it it soldered?
Check the output transistors to see if any are shorted.
Check the output transistors to see if any are shorted.
So I had three shorted output fets. I clipped them out and checked gate resistors. The amp is still in protect.
So back to powering on, playing,output noise is less but still have the protect light on with just power hooked up
It *Looks* like the standard MMATS 4080 fanfare with a custom 4080 eliminator PCB. So U2 and U3 will be mosfet drivers. U1 will be the rest of the missing support circuitry a 4080 would have. I personally wouldn't have poked at any card standing off a socket but it's spilled milk at this point. If you can trace out where the pins of all 3 ICs land on the 20 pin socket then Perry might be able to suggest the components they used to mock up a less integrated 4080.
Is the noise present without a signal? Can you focus in on the noise on your scope? if so, is it fixed frequency? If so, what is it?
It is playing now. The protect light is on with just b+ and b- hooked up. When you apply the remote wire the protect light goes off and the power light comes on. The amp will play.when you take the remote wire off the power light turns off and the protect light comes on.