Roland is a Japanese musical equipment manufacturer. The company was established in April 1972 (See Reference 1). Roland is best known for making keyboards, synthesizers and electric drums. Many vintage Roland products, such as the Roland Juno, are still popular today. Roland products were released under many brand names, notably Acetone. The Acetone PS1000 is a popular vintage synthesizer. If you have a vintage Roland keyboard, the parts may no longer by under warranty and can be difficult to find. Perform your own repairs to reduce repair and parts costs.
Troubleshoot your keyboard to identify the faulty part. Play each key on the keyboard from low to high and note any that are lower in volume. A dip in volume is likely to be caused by insufficient pressure from the key contact. When you strike the key, the key contact hits the contact board. The contact board converts that impact into an electrical impulse. If there are any keys which don't return to their original position, the contact spring may be worn. Turn each dial and make a note of any that crackle. Scroll through your presets. Note any presets that have poor latency or produce no sound. This is likely to be caused by a fault on the circuit board.
Place the keyboard face down and use a cross-head screwdriver to unscrew the base board. Some Roland keyboards, such as the Roland V-Synth, have a joystick for pitch bending (See Reference 2). Be careful not to place any weight on the joystick.
Plug your voltmeter probe into each component on the circuit board. There should be a consistent voltage across the circuit board. For example, the PS1000 has a +/- 15-volt bipolar power supply (See Reference 3). If any components have a reading more than five per cent out, replace them. The filter caps, for example, may cause the voltage controlled oscillator to malfunction. Replacing under performing board-mount parts, such as capacitors, resistors and transistors is likely to correct any sound and volume problems.
Unplug the cable plugs and tape them to the underside of the keyboard assembly. These are connected to the circuit boards. To fully access boards, carefully pull out the cable plugs. Unscrew the circuit board and look for any loose parts or damage.
Unscrew the keyboard assembly and place it to one side. Refer to your notes to identify sticky or quiet keys. Older models have key contact springs, new models have a rubber key contact strip. The Roland V Synth has 61 keys mounted on a key contact strip. These are velocity sensitive. Examine the key contact strip. Use a key contact repair kit to redefine any worn contact strip points (See Reference 4).
Spray plastic-safe contact cleaner onto any crackling potentiometers. These are located on the inside of the top panel.
Place your screws on a piece of electrical tape to keep them in order and prevent them from rolling away.
Make sure that your voltmeter is set to "ohms" when testing the circuit board. Using the incorrect setting can lead to wrong readings.