Buzzer 1 Buzzer 2

(Click on images for larger view.)

The AC indoor unit I own has an 85dB, 2kHz piezo-buzzer on the PCB. I find it unnecessarily loud, so after coming across this question I filled its hole with blu-tack. This muffled the sound it produces, but not as much as I expected. I'm willing to try hot glue in the future.

What I'd like to know is whether it is safe to remove the piezo-buzzer from the circuit. If not, what can I replace it with?

Buzzer 5 Buzzer 6

(Click on images for larger view.)

The schematic diagram and PCB diagram above are taken from the unit's service manual (the location of the buzzer is BZ61). Bearing in mind I don't have much of a background in electronics, and have little experience fiddling with PCB's (sorry!), is there anything useful I can safely assume from these diagrams?

  • 1
    \$\begingroup\$ Just clipping the metal wire leading into the buzzer shown in the top picture should do. Then bend the leads away. This way you can re-hook it up if necessary. No harm will be done. \$\endgroup\$
    – ACD
    Commented Jul 24, 2015 at 12:43

1 Answer 1


You can completely remove it without any substitution. The Transistors are fully biased in the system by resistors already.

In fact, they have slightly over-engineered it, if you ask me, but these days I'd say I'm pleasantly surprised by such things.

You/it should not even notice the removal by a change in power required for the buzzer circuit to any noticeable extend.

  • \$\begingroup\$ Wow ... lets add a few more transistors - just in case. :) \$\endgroup\$
    – brhans
    Commented Jul 24, 2015 at 13:12
  • 2
    \$\begingroup\$ @brhans certainly the first time I saw an appliance use a piezo with a balanced amplifier layout, heck I've seen shoddier speaker set-ups. \$\endgroup\$
    – Asmyldof
    Commented Jul 24, 2015 at 18:41

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