I have a jukebox that stopped playing radio, cd and cassette? any recommendation on where or how to fix it?

This is a power supply problem. First check for a blown fuse where the AC cord comes in to the circuit board. Try to put another fuse if its blown with same rating. If it blow again then there is a semicondutor that has failed. Semiconductors fail by conducting current on both direction therefore creating a short. Example of a semiconductors are: diodes, transistors, regulator packages, chips etc. Transsistor would have three pins. Diodes are usually cylindrical shape with a color band on one end, and has pin on both ends. Chips, and are also semiconductors, but rarely goes out. Thats because most chips run on very small current. The rule of thumb is the bigger a semiconductor device, the more current it operates on, and therefore more likely to naturally fail. So if you were to test one of these components. You would use a multimeter, turn the dial to select "diode" and do a go/no-go test. Meaning you would see if there is contituity on only one direction. Now in that mode, the meter actually display "voltage drop" semiconductors usually have 0.4 voltage drop across one direction, give or take a few fraction of a volt. The other direction there is almost no voltage drop. Thats because it is not suppose to conduct the other way. If you suspect a shorted out diode, or transistor in the power supply, take it out of the circuit, using a soldering iron, then measure it one more time to confirm. If it was bad, note the number on it,and hopefully it is still readable, and replace with the same kind, or one the has the same characteristic.