Sometimes a previous person has mistreated the control, the wiper could be bent or broken, or the volume control itself could have a broken mounting leg which opens the circuit.Īlso, it appears from your picture of the main board that the sound board is a small daughter board or piggy-back board that is connected to the main board. Check the volume control to make sure it is not broken. The design of the sound circuit may have the sound signal moving thru the volume control to the audio amp input. Without a schematic it is guess work somewhat. Then a smaller level audio tone injected on the LM388 input pin and then on the volume control wiper will prove if the audio amp and its input circuitry is working.
Hopefully the cost for it was not too much, and if it does not fix your sound problem maybe you can save the removed LM388 for another repair in the future.īy injecting an audio tone of medium level directly on the LM388 output pin it should drive the speaker to make a sound, proving that all is ok downstream from the audio amp.
I am hoping that replacing the LM388 ic will solve your problem but like a lot of things in electronics you won't know until it is done.
