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DECT baby monitor

slacker878

Dec 25, 2021
3
Joined
Dec 25, 2021
Messages
3
I have a baby monitor that is acting up.
the receiving unit appears to be very soft in volume.

I do not know if its a sender unit problem or a receiver unit issue.
I suspect its a sender unit issue - specifically the microphone, so i bought another cheap electret microphone to replace it - volume is much louder but it resulted in constant static as well.
now i am at a loss and do not know what to do else to test/troubleshoot. is it just the wrong microphone i bought?

original microphone has a DC resistance of 1.26kOhm. no symbols or numbering to indicate maker or model.
open voltage on the end of the wires to the microphone is 2.8v
microphone connects to TP99 (+) & TP100 (-) on the bottom of the circuit.

is it a microphone issue or another common component that can be easily replaced?
I do not have a signal generator , just a basic multi-meter.

thanks.
A

20211225-155930.jpg
 

Bluejets

Oct 5, 2014
6,901
Joined
Oct 5, 2014
Messages
6,901
Call me crazy but I would have started at the receiver amp area.
 

Bluejets

Oct 5, 2014
6,901
Joined
Oct 5, 2014
Messages
6,901
Do you have a circuit diagram.....??
If not, follow back the tracks from the speaker and draw out what you see.
Find the output amp and see what markings are on it.
Google the number to get a spec sheet.
Do some testing based on that.
Or chuck it in the bin and get a new one.
Chances are the parts are oem or not marked anyhow.
By the look of the soldering on #1 red wires you'll need all the luck you can get.
 
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