Seeburg 3WA Wallbox

[Ron Rich]

Gordon,
I have no idea how you are burning out the 2050's, but there is something drastic wrong--2050's are very reliable, just have never seen this happen before ? Ron Rich

[gordo]

Hi Ron and Norman,

The news is not good as I can hear a 'crackling noise' from my Power Transformer.
It stops when I remove the main J501 plug.

So, It appears that I have connected something incorrectly. This may also account for my 2050 failures?

To start my checking process I thought the first check would be that I replaced the Lytic's corectly.
My schematic (page 16022) is a poor print and difficult to read.
Can someone please tell me if I am correct?
The negative sides of the Lytic's both connect to contact number 7 in plug J502.

I will start from here and start checking every trace.

Regards
Gordon....

[Ron Rich]

Hi Gordon,
BUY a new book !! Yes both negs. go there ! Ron Rich

[gordo]

Thanks Ron,

At least they're correct and a good starting point.
The tracks on this board have been worked on so much.

If I could buy a replacement board, I would.

Cheers
Gordon..

[jukenorman]

Hi Gordon,

I also have a pdf copy of the manual that's quite poor but I also have a hard copy that's decent. So having dug out the hard copy, I've had a look at the circuit. I suspect that if the transformer is not happy that the issue must be with the 155VAC which is on J501 pin 7. Can you disconnect the pin 7 line on the stepper side? That would narrow the problem area considerably if that was the culprit. Also, is the transformer "spitting" with the stepper 2050 removed or have you still got a dodgy one there?

It's the same 155VAC winding that feeds the 2050 in the trip circuit.  Have you received your new 2050s and does that circuit work OK?

Norman.

[Ron Rich]

Hi Guys,

Maybe the 155 VDC should be fused ?? Years ago, we added a 1 amp fuse to the detent coil--perhaps we need to move it ?

Gordon,  Check that coil--didja add a fuse ?-- should be about 250 ohms--open to the frame !!--If shorted, it will take out the 2050 !

Ron Rich

[gordo]

Good Morning Gentlemen,

Thanks for your responses.
The East Coast of Australia is getting smashed with rain with 1000's of houses lost.
I have my son's family moved in with us while the floods subside.
Little time for jukebox work.

Norman, J501 pin 7 is my suggested problem area (hence my previous question that Ron answered)
The circuit board tracks in the area are very poor.
I intend to clean them all up and run some wires where needed.
I have tried without success to find a replacement.
If I disconnect the J501 plug, the transformer still 'spits'.
So, I assume this narows the problem to the Stepper Electronic Unit Board. (would you agree?).
Still awaiting my 2050's.

Ron, I have not added a fuse.
I assume you mean for me to check the number stepper coil?
If so, I had all sorts of problems with this and it's very 'dodgy'.
It reads about the 250ohms but the windings are rough and a bit tangled.
Could this be shorting the 2050? Can I test it for shorts?

Cheers Gordon..

[Ron Rich]

Hi Gordon,
Good luck on the floods---
I meant the Detent/trip coil on the mechanism--250 ohms should be OK on the other one also-- Ron Rich

[jukenorman]

Hi Gordon,
Sorry to hear of the floods! I would say that if you disconnect the stepper feed and the transformer still spits, that would suggest it isn't the stepper? If you also disconnect the mech feed J751 as shown on page 13009, does it still spit? Ron's previous suggestion of a fuse in the 155VAC line is a very sound one!

Anyway I'm sure you have other priorities meantime.

Norman.

[gordo]

Hi Ron and Norman,

Sorry, I have been caught up in other issues.

I'm still waiting for my 2050 tubes to arrive.

I am unable to select any songs (no 2050 tube) so I am unable to check if the jukebox is working at all.

I tried to locate the source of any shorting that may be causing the power transformer to burn.
I removed every plug from the rear door and added them back one at a time.
All good except when I added plug P511 which joins the Stepper Electronic Unit to the Stepper unit.
It started burning the Power Transformer.

So, if I assume the problem lies within the Stepper Unit.
All that is on that unit are 3 coils (Number coil, Letter Coil and Reset magnet) and all the contacts.

Could it be one of these three coils?
How can I test if a coil is shorting the transformer?
They all measure the correct ohms?

Could a bad coil also be shorting out my 2050 tube and the transformer? 

Cheers
Gordon....

[Ron Rich]

Hi Gordon,
My GUESS is it's going to be in the 155 volt area-- meter it - see if you can see if, where it goes to earth, or other power source -- power OFF !! Do not allow it to "cook" any more,m or you will, for sure, need a new transformer ! Yes-- if the 2050 tube and that hi voltage is crossing-it should destroy the 2050-- FUSE it NOW ! Ron Rich

[jukenorman]

Hi Gordon,
Yes absolutely fuse it! Also do not connect power to the stepper again until you've found the fault. Although you're breaking the circuit at P511, the fault might not be within the stepper section. I would suggest that you should disconnect at J501 and reconnect P511. Then try connecting your lamp tester between the 155V line and ground - see if you can identify the leak path. You might have a bit of to-ing and fro-ing before you find it.

Norman.

[gordo]

Hi Ron and Norman,
Thanks for your reply.

Where do I add the fuse?
What size fuse should I insert?

How do I actually test for grounding within the 155V line?

Regards Gordon...

[Ron Rich]

Hi Gordon,
Add the (2 A ?) fuse at the end of the 155 volt wire from the transformer--- Measure resistance to ground on both transformer wires-- you may need to un-solder things till you "find the culprit"-- I would take a GUESS that you will find it near the coil that was "messed up"-- Ron Rich

[gordo]

Thanks Ron,

I'll let you know how I go.
Gordon..