Elenco Auto-Scan FM Radio Model FM-88K Troubleshooting
The Eleneco FM Radio is a educational product sold by Elenco. It is a simple device devised of relatively few components. There is very many problems with these radios. As long as you can get a hold of extra capacitors, resistors, solder and a soldering iron, you should be able to conquer ony issue.
Typically when the battery dies the LED will no longer turn on and noise will not come out of the speaker. Try replacing the 9-Volt Battery.
Bad solder connections can be spotted with the naked eye. If this is the problem then you may find some cold welds, which means the solder did not settle right giving it a scuffed look instead of shiny. The other problem could be that a sufficient amount of solder was not added to area of the connection. Using a multimeter, check the voltage across each component. Begin the testing at the positive terminal of the voltage source and systematically check through the circuit until you find a component that has a voltage reading of zero. Try to solder this connection again.
The first connection you may want to test is the capacitor labeled "C-22." This capacitor amplifies the radios capacity to receive radio signals. If there is no current flowing through the capacitor then you may want to replace the capacitor or solder the connection again. If the C-22 capacitor is working properly then you may want to systematically check each connection again until you locate a component that has 0 voltage passing through it. Try soldering this connection again. If this does not work then you may have to get a replacement for this component.