I am trying to repair a Friedland wireless doorbell receiver which has stopped sounding the chime.

I have found that the 16 Ohm speaker is no longer working. The amplifier circuit for the speaker is an LM386.

If I connect a small external powered amplifier to pin 3 of the LM386, I can hear the chime.

What I found odd was that with a 12V DC supply to the LM386, there is approximately 5V DC continuously on the output (pin 5) and about 4.7V DC after the 220µF DC block capacitor where the speaker connects?

Is this normal or could that be why the speaker has failed?