Troubleshooting SC-1 -> RCSU5 -> LPC480

[en]

Hello all,

Could use some direction trouble shooting connecting SC-1 to LPC480 via RCSU5.

Contacts have all been cleaned everywhere I could find. Coil resistances on stepper check out.

I've grounded the grey wire on APU per a post on another site. This is my understanding of 'free play' setup.

I can select letter/number and the SC-1 wheel turns and pulses are seen at the the stepper.

Nothing happens after that, the relays that start the mech moving never trip.

The symptoms are exactly as shown in this video:

www.youtube.com/watch?v=QQ60syJwUoI

Any directions to try would be much appreciated.

[jukenorman]

As far as I can tell, in the video the transfer from letter to number stepper is not happening - is that what your one is doing?

Norman.

[en]

Thank you for the help.

That's a good question. I would say that both wheels in the stepper operate when letter and number are pressed on the consolette. I will double check that today.

Once the stepper wheels stop, there is no more action. The carriage never starts moving. That video is not of my setup, but it's what I am seeing on mine.

[en]

With a closer look, it appears the the wheel closest to the front of the unit does not move very much. Only enough to trip the switch that rides on the edge of the disc, but certainly not as much as the one in the back. I think that's what you mean by letter (back) stepper vs number (front) stepper.
Any help or next thing to check is appreciated.

[jukenorman]

The back one is step relay #1 and it should operate first, the front one is step relay #2. Is #2 free enough to be able to be operated manually? The initial pulses go to step relay #1. These pulses also keep the transfer relay energised; there is a time delay on the transfer relay and it shouldn't drop out until the gap between the two pulse trains.

I've just had a look at the SC-1 manual and it appears that the number pulses are delivered first (unlike the 3WA). So if you were to select V8, you should hear 9 pulses, short gap then 20 pulses. These should advance both step relays to maximum. If the step relay #2 doesn't advance at all, selection V8 should maybe provide enough time to check the status of the transfer relay.

Norman.

[en]

I spent a lot of time yesterday observing and checking things. The step relay 2 never seems to operate so I am focused on that (as you are!).
Your description of how it should be pulsing on V8 is very helpful. Now I have something to shoot for.

To answer your question, the #2 wheel operates freely and can be rotated easily with a screw driver. If you mean the #2 relay, that's a little harder to determine when the stepper is installed and powered.

I'll continue today to see if I can figure it out.

Thank you again

[en]

Well, as one might expect, a simple issue has resolved this.
A closer look at step relay 2 and I saw that the upper part of switch 'J' was bent such that it did not close when the coiled pulled in.
I adjusted that and now a selection on the consolette results in the mechanism scanning for and playing a record properly!

I did notice that V8 selection actually is very few pulses and A1 is many more. I have to investigate this further since when I select A1, the mech picks up and plays D1; B1 picks up C1, and the like all the way thru A8->D8. The other banks of records starting with E1, etc. seem to be fine.

So off to figure that out next. I think either configured the stepper wrong, or some contacts need more cleaning.

[jukenorman]

I've obviously got the pulses the wrong way round! I did have it in my head that this was the opposite of the 3WA which I'm much more familiar - so A has the twenty pulses! In which case, it's likely that it's the contact rivets on the selector plate in the wallbox that require attention.

Norman.

[en]

I can report success and full function!
The group 7 wiring setup on plate #2 in the stepper was not correct resulting in A1 selection routing to D1, etc.
Consulted manual to check all setups. Correcting this has resolved it.

Per most troubleshooting I've ever done on the LPC-480, and now the wallbox and stepper these issues were around what is often repeated here and on other online sources:

- Clean all contacts, lubricate all moving parts first.
- Check that all switches are closed/open at the right time or state of operation.
- Read the manual!
- Specifically for steppers: check for free operation of the stepper wheels. I originally had the white plastic and cracked wheels which were completely bound up and didn't step. Replaced with black wheels and good to go.
- Be patient and methodical.
- Ask for help

Thank you again.