Converting a Seeburg jukebox for free play operation is a popular modification for home use. It eliminates the need to find coins and eliminates coin gear jams. The “old” way to free play a Seeburg was to bend the little ramp inside the CCU so that selections were not cancelled as the CCU wheel rotates. The pitfall to that approach was that the latch bar solenoid inside the selector would remain energized for long periods of time; this causes the latch solenoid to burnout, and it can even be a (slight) fire risk.
Another method to free play a Seeburg is to wire a push button switch into the coin gear switches, and ask the user to reach around to wherever that you mounted this switch. This method is rather crude in my opinion, and often requires drilling a hole that could be avoided if a different freeplay method was chosen.
Here is a popular freeplay conversion for 1950s Seeburg jukeboxes M100C, 100W, HF100G, HF100R, 100J, 100JL. This conversion is not my own. It has been floating around the internet for quite a while.
Obviously, common sense disclaimers — do not try this at home — experienced technicians only. Remove all power to jukebox and practice safety precautions.
- Locate the CCU (Credit and Cancel Unit, which is mounted on the selection receiver). Unplug the coin gear and leave it unplugged, as it will no longer be used. You may want to lightly coat the 4-pin coin gear plug socket with some hotmelt glue so that no one accidentally plugs the coin gear back in.
- Make sure that no credits are on the CCU.
- Underneath the octal socket in the CCU, jump together pins 1 and 6. Remove the connections from socket pin 7, and insert a 1N4007 diode between those connection and socket pin 7. Anode side of diode goes to socket pin 7, cathode side of diode goes towards the connections that you removed.
- I suggest that you put an instruction sticker on the CCU metal case that explains this mod, so that future owners of the jukebox will understand why the selector is working in this manner.
That’s all there is to it. The latch bar solenoid will now only engage when someone pushes a button (either letter or number). It will stay engaged until both a letter and number button are pushed. A selection will be made, and the latch bar solenoid will release.
Obviously, if someone were to engage only one button (either letter or number), the latch solenoid would stay engaged. This behavior is the same as previous coin operation — if someone had inserted a coin, pushed one button, and never finished making a selection. In this situation, you would still risk burning out the latch solenoid, but obviously such a situation would be extremely rare. I am not aware of anyone who presses one button and never finishes making a selection.