Amplifier send power to the speakers but no audio

Thread Starter

TieBravo

Joined Aug 21, 2021
50
Hello i was scavenging my dads "garbage box" yesterday. I found a very simple amplifier and a fm radio receiver circuit. A 9v transformer was connected to the amplifier with a 4700uf cap parallelly. It was working before my magic touch ☹. But when i desolder the transformer output to dust things off and give it a shape and solder them back, MAGIC! no music is playing but speaker got a cracky noise when i switch on the transformer.
I have also tried using my smartphone to send it Audio (which was working before) but no results.
I am sorry I couldn't remove the heatsink.
Update: ic is CTC810
 

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Audioguru again

Joined Oct 21, 2019
3,632
A transformer produces AC. the bridge rectifier and 4700uF capacitor convert 9VAC to about 11VDC.
The solder joints on the wires has the solder falling apart. Didn't you use rosin-core tin-lead solder?
 

Thread Starter

TieBravo

Joined Aug 21, 2021
50
A transformer produces AC. the bridge rectifier and 4700uF capacitor convert 9VAC to about 11VDC.
The solder joints on the wires has the solder falling apart. Didn't you use rosin-core tin-lead solder?
Yah i do have that, maybe i didn't wait for the solder heating up completely. But can you tell me if i damaged the circuit ?
 

Audioguru again

Joined Oct 21, 2019
3,632
To solder a wire on a pcb you do not drip the solder from up high, instead the soldering iron tip is placed on the joint and solder is added. It takes 1 second of time to do it.
 
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