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Post by jukenorman on May 23, 2021 9:41:28 GMT
Hi Eugen,
I would also be wary of increasing the fuse value - it's there to protect the selection coils. What may be a better option would be slightly shortening the write pulse? There's a 100uF capacitor on timing relay number 1 (did you change it out?). I haven't studied the circuit but I'm guessing that reducing that capacitor value would shorten the pulse - maybe try a 50uF + 33uF? Or maybe even a different 100uF capacitor might be enough, the tolerance on these is quite big!
Norman.
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Post by Ron Rich on May 23, 2021 11:45:52 GMT
Hi Eugen,
You might look at the area of the relays, where the armature contacts the pole piece-- sometimes there is a build up of "dirt" there. Just use a business card saturated with a safety solvent to clean that area-- Also look at the tail spring-- has the spring "hook" been bent ?? Ron Rich
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Post by viperz on May 24, 2021 18:00:35 GMT
It is definitely 24 VAC, so it is not for selector coils. It's basically TR1 and TR2 from what I can gather?
I cannot reproduce the issue again. Have to leave the jukebox cold for a week or two. I'm honestly thinking about just bumping to 500mA SB fuse at this point.
Ron, I did clean those spots on TR1 and TR2 previously. So not sure what causes most likely TR2 to stick just once when not used for a long time.
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Post by jukenorman on May 24, 2021 19:14:28 GMT
Hi Eugen,
I do not have a 1900 manual but looking at the picture you posted on 21st May, the fused AC (0.4A) passes through contacts of TR1 and TR2, then through the number selection pushbuttons to coils which look suspiciously like selector coils to me?
Norman.
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Post by viperz on May 27, 2021 19:59:52 GMT
Norman, yes, I see what you mean. I tried to replicate the issue, but I cannot anymore. I had the machine off for 5 days, turned it on, and still no problems. I want to try one more thing - put a quarter in it, get it to register the coin, then turn the machine off. This way when I turn it on next time, the relays should pick right away - maybe that's what caused the issue.
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Post by viperz on Jun 6, 2021 20:09:24 GMT
I think it is just time that takes the whole thing to warm up. I have turned on this jukebox twice in two weeks. Turn it on, give it 3-4 minutes to warm up (still should really do it every time for the tube amp), then it starts with no issues. This thing also ate one of the dimes for the first time - somehow it managed to skip the coin stopping lever at the bottom and went into the bag (first time in 200+ plays on dimes). I like testing with dimes rather than quarters (3 plays for 25) or with add-credit button - this way I get one full cycle on a dime...
Also been a month since Stamann put my leftover parts on the ship. Hopefully that ship is somewhat closer to Canada by now.
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Post by viperz on Jun 22, 2021 23:31:19 GMT
Woohoo, parts from Stamann finally came in. I can finally rebuild the pilasters and reinstall the title holders frame.
I also ordered new green cartridge. The note that came with it says to adjust pressure to 5g. My tracking right now on the current green cart is closer to 10g. When it was at 7-8g, the sound was muddy.
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Post by viperz on Jun 23, 2021 12:47:32 GMT
Hm, received confirmation from Stamann that yes, they strongly advice to go with 5g with their new green cart. Since my jukebox is completely assembled, now I cannot use the digital force gauge to set the pressure, and will need to source that damn mechanical gauge.
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Post by viperz on Jun 23, 2021 17:17:08 GMT
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Post by jukenorman on Jun 24, 2021 8:11:40 GMT
Looking good Eugen! You'll be pleased with how it has turned out!
Norman.
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Post by whammoed on Jun 24, 2021 14:42:14 GMT
Wowee! Looks great! I have owned 2 jukes in the past and tell my wife everyone should have 2 haha!
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Post by viperz on Jul 9, 2021 3:20:43 GMT
Printed, cut and installed the title strips. They look great with the light behind them. Also, bought the tension force gauge, installed new Cobra cartridge, and dialed down the force to 5-6 grams. Sounds fantastic for a Cobra. Photo with title strips: photos.app.goo.gl/sTKwvqk8CdSY9qVy9 |
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Post by viperz on Aug 4, 2021 2:59:54 GMT
Looks like I will have to figure out this fuse blowing issue after all. Haven't used the jukebox for a couple of weeks. Warm it up for half an hour while playing the other jukebox. Select first song - fine, 2nd song - puff, the 500mA SB fuse blows. It is really getting annoying as I can play for days with no issues, but if it sits, it is almost guaranteed to blow that fuse for some reason. As soon as my workshop benches will have space, I will start following Norman's and Ron's suggestions... This 28VAC seems to go to TR1, TR2 and selector coils? photos.google.com/share/AF1QipOFc1mAYKu-2cpgaTcDPi0f7WtOBolSKGo8SNm0M7UurYklsqUrxwiMBnd0mtQQzA?key=Zm9lWUR3UlVXek1YNUVLbkZiSGZDV2JMTUdJWnZRWhen the fuse goes, I am still able to 'make selections' meaning I can push letter/number, and credit gets subtracted until I run out of credits, it just does not select or play records anymore... Even if it is a specific coil shorting out, I am still able to select the same song without blowing the fuse after replacing the fuse. Would really checking/adjusting TR1/TR2 contact spacing make any difference? |
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Post by viperz on Aug 4, 2021 15:49:01 GMT
Played all 20 songs that I have loaded, one by one, none of them blew the fuse, so I am fairly sure it is not a selector coil blowing my fuse, unless it is somehow very intermittent.
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Post by jukenorman on Aug 4, 2021 16:43:18 GMT
Hi Eugen,
I would look particularly at TR1 because it is switching both power from the blowing fuse and ground - make sure there is no chance of any stray strands of wire from either that are likely to touch for example. I also previously suggested changing the timing capacitor on TR1 and I think you should do that as a matter of course because it is critical to the operation of the circuit. I did also suggest reducing its value but I'm going off that idea having given it a second thought!
Norman.
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