Fixing record players requires mechanical and electrical knowledge. Record players function on the basic principles of physics and geometry. The turntable rotates the record at a set speed. The needle reads the vibrations the groove produces, and this physical vibration is turned into sound or an electrical signal that is amplified for playback. After learning basic principles of diagnostics and mechanics, you too can diagnose and repair record players of historic or sentimental value.
Turn off and unplug the record player. Visually inspect the record player for signs of damage. Look for chips, dents and missing or broken parts. Compare them to a photograph or manual describing the record player when new. Prepare a list of damaged parts for replacement.
Inspect all connections to the record player. Begin at the power source by examining all plugs and cables for frayed or damaged connections. Verify that the outlet the record player is plugged into is not switched off.
Turn on the multimeter to test for continuity at all cables. Check the turntable plug and wires for continuity by connecting the leads of the multimeter to both ends of the tested cable. Replace faulty sections.
Connect the multimeter to the signal cables to test for shorts and continuity from the plug to the cartridge connections. Inspect the output cables for secure physical and electrical connections. Use a signal tracer to generate a test signal to test the signal path through the output cables. Verify the operation of the output cables and replace one or both if necessary.
Visually inspect the needle on the tonearm. Verify that it fits and operates properly by turning the turntable on and testing it on a record. Replace the needle if it is faulty or missing. Listen and compare the sound output of the old and new needle.
Test the cartridge for operation if all other components are in order. Occasionally, a cartridge will fail. This occurs when all connections are working and the needle operates properly but the cartridge does not generate a signal. Note the model and manufacturer of the cartridge and record player when buying replacement parts.
Use a screwdriver to dismount and replace the cartridge. Disconnect the old cartridge and connect the new one.
Replace faulty, frayed or damaged tonearm cables. The cables may connect to the phonograph cartridge with either crimp or solderless connections. Be careful when threading replacements through the tonearm as these wires are thin gauge and damage easily. Cable connections may be dirty or corroded. Remove and clean the connections with emery cloth or sandpaper and reinstall.
Visually inspect the drive system. Modern turntables are of two types: direct drive and belt drive. For direct-drive turntables, an AC motor is switched on and rotates a drive wheel, which rotates the turntable. The rubber on the drive wheel can deteriorate over time or lose its grip, in which case it must be replaced. A belt-driven turntable uses a motor that drives a belt to turn the turntable. The belt typically fails first, and may be due for a replacement. In addition, the motor or switch may have failed if the turntable does not rotate at the proper speed. Inspect the motor and housing for scorch or burn marks and replace if necessary.
Inspect the turntable platter for warps or vertical movement as it rotates. Warps or vertical movement indicate a twist in the turntable platter, which introduces audible distortion or needle jumping on playback. Replace the damaged platter.
Parts may be out of adjustment and do not need to be replaced. Some record players allow for fine adjustments that may be required periodically, as documented in the user manual. Lubrication and recommended scheduled maintenance is also typically identified in the user manual. To prevent misdiagnosis, verify that your amplifier or preamplifier and connections are on and functioning.
To prevent electric shock, disconnect all power cords when testing power cables.