Check the power cable to make sure that it is plugged in. Examine the cable for damage that might keep the unit from operating.
Reconnect the audio cabling connected to the inputs and outputs of the machine if it is loose. Check the inputs and outputs of where the cables lead to your console, computer or digital audio workstation. Test the cables with a cable tester to rule out faulty cabling.
Turn off the tape machine and keep it from other audio devices and analog audiotape. Demagnetize the tape heads with an electronic demagnetizer by slowly moving it around the tape heads while it is plugged in. Demagnetizers are found at most audio supply stores and electronics retailers. Always move slowly when using a demagnetizer.
Remove the recorder's exterior with a screwdriver and inspect the moving and rubber parts to make sure they are probably lubricated. Rubber parts should be firm, yet springy, and should not appear worn and shiny. Damaged moving rubber parts inside a recorder often are responsible for improper playback.