[Jukebox-list] Missing part of Wurlitzer 3700 Service Manual

[Ron Rich]

Gregor Anich <blight at blight.eu.org> wrote:    On Friday 02 February 2007 05:59:21 Ron Rich wrote:
> Answers in text, below, at (<)---Ron Rich
> >

Yes, in the manual it is referred to as the "Bonus accumulator" in some 
places.

.

>
> First of all, when I activate the free-play switch the selection
> accumulator doesn't start rotating immediately anymore, it starts when a
> letter and a number were pressed.
> Then the correct latch pin is released by the solenoid in the selection
> accumulator, it stops rotating and the keyboard switches are released.
> < All above is the correct sequence of operation

What should happen as the next step? Should the magazine start rotating?
  YES

I tried today and I think it was not stopping after two rotations. During the 
third rotation the 8A fuse in the control box blew but I think that was 
because I replaced the triac TR1. Gotta get some more of those fuses...

 It could be a mechanical problem with the override switch not opening--very common--as for causing the fuse to blow, I don't think so--
   
  > When the scan-load-run switch is in the run position the magazine lock
> solenoid should get current from signal 71 which is connected with a 10
> Ohms resistor and 0.47 uF (?) capacitor in series to signal 64.
>
> > wire colors designators in older phono schematics--I don't know if that is
> still true on that model. If true #64 should be a yellow wire, with a blue
> tracer.
>

Yes, it is a yellow wire with blue tracer.

> Signal 64 comes out of the triac board from TR1.
> There's a override relay which is activated/swiched as soon as the jukebox
> gets power and which connects the gate of TR1 to GND when it is active (I
> checked that with the DMM)
>
> 
  > < I think that you have found the problem--
>

One of the problems. I replaced the triac TR1 by a good one, and when removing 
the old one I found out that it was really blown! (probably because someone 
bypassed the 8A fuse...) The TO-220 case fell apart (the cooling plate came 
off the device and you could look at the internals) - never seen that 
before ;)

I wonder if you have any ideas - there doesn't seem to be much connected to 
the output of that triac but I don't yet have any idea what might cause the 
8A fuse to blow/what shorts the output of TR1.

I hope the replacement which I used for TR1 was ok, it was a BT137-600 600V/8A 
triac from my cheap soldering station.
Is this a proper replacement for the original which was Q2010L4 I think? 
(200V/10A like the other two triacs on the triac board)
   
  I can't find my Wurly replacement parts list, but have a note on the parts page in my 3700 manual-- #140769 triac's use NTE 5004 or NTE5633/5/7.
  I always replaced all three at once--also have a note that R-11 needs to be  5 watt resistor--
   
  Ron Rich

 
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