Conn brand organs were fairly common tube-style organs that were typically designed to simulate the slow attack time of a pipe organ, making them popular for classical music. Conn went out of business in 1979, but many of their organs are still readily available on the used market. However, repairs are often quite difficult, and major electrical problems should be evaluated by a professional technician. There are some problems that users and musicians can fix though, which are very common among tube-style electric organs of all types.
Organ Will Not Power Up
Unplug the organ from the wall outlet or surge protector. Move the organ away from the wall so you will have access to the front and back portions of the organ for repairs.
Remove the power cable that is connected to the organ. If the cable is not removable do not attempt to remove it by cutting it. Some Conn organs have removable power cables while others do not.
Test the power cable with a multimeter which can check to make sure your organ is sending and receiving enough power to function. All multimeters are different, so if you do not know how to test the power cable, you need to read the instructions in your operation manual.
Replace the power cable with a new cable of the same type if you have a removable cable. Do not attempt to repair an unattached power cable yourself. There's a serious risk of electrical shock. Seek help from a professional technician.
Low Audio Output
Turn the organ around so you have access to the back panel where the vacuum tubes are located.
Plug the organ in and allow it to warm up for 15 to 20 minutes.
Inspect the vacuum tubes to make sure they are all lit and none of them are dim or flickering. Make a note of any tubes that may have a problem.
Turn the organ off and allow it to cool down for 30 minutes. Replace any damaged tubes with a new tube of the same type.
Plug the organ back in and test it by playing something. Damaged or partially working power tubes are a common cause of low volume on older organs, especially if they have been moved recently.
Do not perform any repairs, even basic ones that you are not sure how to do. You could damage the organ further, which will just cost more money when a professional repairs the organ.