Wurlitzer 3700 bypassing BO/AC unit

JDB · by **JDB** » Mon Jul 27, 2015 8:28 pm

I want to put a Wulritzer 3700 on permanent free play mode and bypassing the BO/AC unit with a jumper on BO/AC connector pins 2 and 6. When I do this the latchsolenoid starts clicking like crazy (retracting/releasing). I am new and not native English speaker and try to respect definitions from the manual. I hope someone can help.

Thanks in advance!!

by **Ron Rich** » Tue Jul 28, 2015 1:40 am

Hi JDB,
Remove the plug going to the BO/AC, leave it "hang". Jump pins 2,6,7, and 8 together in the female BO/AC socket.
If it still won't work, check the switch that the plunger activates. Ron Rich

JDB · by **JDB** » Tue Jul 28, 2015 5:59 pm

Dear Ron,

Thanks I appreciate your help!!

I jumped Jump pins 2,6,7, and 8 together in the female BO/AC socket. I also disengaged the latch solenoid plunger from the arms operating the switch. In this case the latch solenoid stays retracted in free play position.

Additional info:

I switched the "5 watt 85 ohm resistor" related to latch solenoid for a new "5 watt 85 ohm resistor" This resistor became so hot it produced smoke. I replaced it with a new 10 watt 85 Ohm which worked much better.

The manual says latch solenoid "chattering" comes from the resistor, so I again replaced it with a new 10 watt 85 Ohm (as newbie I always order small parts double). When the resistor was totally removed, I tried the jukebox and the latch solenoid started chattering at twice the speed as with the resistor. Can anyone help.

Thanks in advance

by **Ron Rich** » Tue Jul 28, 2015 7:32 pm

Hi JDB
Well, one should never power that coil without the switch being activated. The coil should get "full power" only long enough to start to pull the plunger in, at which point the contacts that jump the resistor, open, and place it in series with the coil. Did you check the functionality of the switch ? I do not re-call which type switch was used in that model. Earlier models used open blade type, later ones had a black plastic slide switch. BOTH are prone to fail ! Also, WurliTzer used two different brand coils for that app, that required different value resistors. Are you sure you have the correct pair ? By now, you also may have a partly shorted coil ? Check the resistance with a meter/against the schematic/parts list, and be sure the correct coil/resistor is installed.--It's normal for the resistor to be hot--
One other thing--by chance, did some "Geppetto" modify ( shorten) , or change the spring that pulls the plunger out ?? Ron Rich