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Wurlitzer 1900
Posted: Mon Feb 10, 2014 10:47 pm
by wedgehead
I am new here, and have a service manual. I have my 1900 up and running but have an issue that I can not see the flow on the schematic.
the 1900 will only select D , if I press A1 D1 is loaded if I press c14 D14 is loaded
anyone that push me in the right direction ?
i looks like the D is stuck engaged
I have a strong background in EM pinball machines so I have some knowledge on older machines.
Re: Wurlitzer 1900
Posted: Mon Feb 10, 2014 11:08 pm
by wedgehead
added note. i check the physical A B C D Buttons on the panel and they look to be functioning correctly. i think the issue is down stream
Re: Wurlitzer 1900
Posted: Mon Feb 10, 2014 11:41 pm
by wedgehead
update: i managed to get it to select a1 but had to manually move the wobble plate. still confused on what actuates the wobble plate coil?
Re: Wurlitzer 1900
Posted: Tue Feb 11, 2014 12:05 am
by Ron Rich
One thing to check on that model--make SURE that there is a large piece of "fish-paper" glued under the ABCD buttons --it should be attached to the casting. If not there, that machine will do jut what you describe, plus, other "crazy"things"
Wobble plate is controlled via the four buttons-(ABCD), as far as I recall--check the schematic tobesure--
Ron Rich
Re: Wurlitzer 1900
Posted: Tue Feb 11, 2014 2:46 am
by hirdlej
I'll add another bit to this as well, a friend of mine was having issues with his 2104 where the selections were always 1 off. If he did B2, he got B3. If he did B3, he got B4, etc. I stuck my head in the machine and took a look. I found that on the keyboard plugged labeled "2", that the keyway was broken. He didn't have the plug clocked right and it was off that 1 position. Check all your plugs in the front and make sure the keyways are there and that none of them are missing or cracked off. Good luck and let us know.

Re: Wurlitzer 1900
Posted: Tue Feb 11, 2014 2:53 am
by wedgehead
ok went back to the schematic, I think the issue is the driver solenoid
my reasoning is as follows
A-is determined by the stop finger (no circuit)
B-is determined by B stop magnet
C-is determined by C stop magnet
D-uses a circuit that uses the driver solenoid determined by stop finger
does this sound correct?
ok now to find the driver solenoid
Re: Wurlitzer 1900
Posted: Tue Feb 11, 2014 3:01 am
by wedgehead
ok the coil that moves the wobble plate is the driver solenoid.
it looks like it is not energized ? so why is D being selected?
I will have to put a meter on it once I get time and the shop isn't 20 deg F
Re: Wurlitzer 1900
Posted: Tue Feb 11, 2014 5:08 am
by Rob-NYC
"Wedge" Since "D" is the farthest travel of the rocker assembly, my guess here is the rocker assembly center bearing is frozen and not allowing the spring to rest it.
My old shop manuals only go beck to 2104 -but that is essentially the same. Frozen bearings are common on those old machines, the oil has turned to molasses.
I had a similar problem on one of my 2300's. In thta case the crank/stop switch assembly was sludged and stuck. Even after the whole mech was bathed and degreased, that center shaft had to be taken apart. A heat gun would free it -for a while. but only getting out the old grease permanently fixed it.
Rob/NYC
Re: Wurlitzer 1900
Posted: Tue Feb 11, 2014 12:31 pm
by wedgehead
rob/nyc
I am not sure that is the case with mine? if i move the wobble plate as the A button is pressed the press a # BUTTON it will load the A title.
so from what i understand (which is little at this point) that the D selection is for some reason stays active due to it being the only one with a curcuit.
Re: Wurlitzer 1900
Posted: Tue Feb 11, 2014 5:04 pm
by Rob-NYC
Well, this statement is what confuses me:
ok the coil that moves the wobble plate is the driver solenoid.
it looks like it is not energized ? so why is D being selected?
As I see on the schematic, if the driver solenoid is not energized all selections are to be "A". If the solenoid is not pulling and you still get all "D"s then the problem is mechanical.
Does the driver coil pull on "B" or "C" -?
BTW: The "wobble plate" is what gets pushed upwards by a selected pin and starts the AC relay to initiate search/play. The part that punches pins is the rocker assembly
Rob
Re: Wurlitzer 1900
Posted: Tue Feb 11, 2014 6:02 pm
by wedgehead
Rob
let see if i am looking at the wobble plate correctly.
if you are looking at the wobble plate from the front of the jukebox through all the other parts
the plate at rest moves counter clockwise when activated correct OR does the coil release it and the wobble plate moves clockwise when activated ?
i think i may be looking at this backwards. if that is the case than the drive coil stays on
(i may have a bad coil) i will ohm it when i get home and see what i get.
I did see the C magnet coil move when C button is pressed but if the D- driver coil is locked on then that would override any other button A, B Or C
Does that sound correct?
thanks for helping out i know sometime it is hard to help when the other person doesn't know the correct terms
Re: Wurlitzer 1900
Posted: Tue Feb 11, 2014 6:41 pm
by Ron Rich
As Rob wrote--it is NOT the "wobble plate" that you should be concerned with--yet--it's the "Rocker Plate"
If NOT "Gummed up" ( coil, OR, linkage) did you check for the "fish-paper" I wrote about above ?
If neither of the two items above are "bad", did you check all plugs for "keying", and to be sure they are plugged in correctly ?
If all of that is correct--check continuity of all wires to the four switches, thru the plugs/sockets, to the J box.
If it still fails--check power supply to the coil--
Ron Rich
Re: Wurlitzer 1900
Posted: Tue Feb 11, 2014 7:07 pm
by wedgehead
OK ron
if i get time after work i will go through the list you gave me and see what i find and report back
thanks again
Re: Wurlitzer 1900
Posted: Wed Feb 12, 2014 4:25 am
by Rob-NYC
Re: Wurlitzer 1900
Posted: Wed Feb 12, 2014 12:16 pm
by wedgehead
Ron Rich wrote:As Rob wrote--it is NOT the "wobble plate" that you should be concerned with--yet--it's the "Rocker Plate"
Thanks for the scans Ron; they look the same as what is in my w1900 manual.
The term” rocker plate” I can not find on the print. Their are short and long rockers that are associated with the selector solenoids. Is that what what you are referring to?
thanks