Hey guys, I am relatively new to micro electronics, and am in desperate need of help!

I want to bypass the muting circuit in a electronic piano. This involves either activating the relay, or pulling it to ground (BA3-5 Relay, and the highlighted LS1 in the picture below).

Please could someone help with the relevant connections required to bypass/activate/deactivate the relay?

Thanks in advance!


For more information:

This is a Kurzweil CUP2 digital piano that is completely not working, and I think it is a problem with the engine board, but have no idea what the source of it is at this point. (No response from LCD interface or buttons; no native audio passthrough. Only the "ON" LED works). The speakers are muted during startup to avoid any crackling sounds through the engine board. I am hoping however that by bypassing the mute relay I could still use the piano in its most basic form?

Datasheet: http://www.handouk.co.kr/english/02_product/telecom/products/ba3.php --Relay "datasheet"
https://elektrotanya.com/kurzweil_cup2_sm.pdf/download.html --Service manual with all schematics

 

Forget about bypassing the relay.
Fix the existing fault first.

 

Forget about bypassing the relay.
Fix the existing fault first.

I would love to, but unfortunately I have absolutely no idea what the root of it is... If I can verify the audio through works, then the problem can be isolated from the interface board to just the engine board?

 

Presumably the “engine board” is what produces the sound, so if it is not working, don’t know how you expect it to produce anything.

If you want to see is any sound is coming through, short pin 1 of the relay to +5V. But I would not expect to hear anything.

 

Your question is not clear.

Do you want to bypass the relay so that the outputs are always on?

Or bypass the relay so that the outputs are always muted?

Or have independent control of the relay to activate/de-activate it at will?

ak

 

Your question is not clear.

Do you want to bypass the relay so that the outputs are always on?

Or bypass the relay so that the outputs are always muted?

Or have independent control of the relay to activate/de-activate it at will?

ak

Hey! Thanks for the response! I think that the relay is naturally in a engaged position, and the microcontroller then disengages it to allow sound to be engaged.

From the Manual: " associated circuits sense the presence of headphones and deactivate relay LS1 to ground, the return signal, and thus mute the speakers. "

 

I got that from the schematic. My question was about what you want to do.