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Old 19-09-2017, 03:52 PM   #1
BigTed
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Default CDU issue?

Pah! All seems to have gone wrong!

I had almost all my point motors (Peco PL-10E and gaugemaster PM-1s) wired up and working. Double throws, everything.

Then, suddenly, today, one by one, they stopped working.

It's like they're running on far less power.

I have sprun switches.

The majority of the single points wouldn't throw. They moved, twitched, made a noise, but didn't throw. Some of the double throws, one of the points would throw but not the other.

This was all working a day ago.

When I went up there I THOUGHT I heard a noise from the CDU (It's a Cobalt one). It could have been something falling off the baseboard, something falling over, but I thought it came from the CDU.

The lights still come on, to say it's charged, and they still come on quick, it just doesn't seem to be sending much power out.

Does anyone have any suggestions?
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Old 19-09-2017, 04:07 PM   #2
John squiggly
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Loose connection. Dry solder joint. Just thinking out loud.
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Old 19-09-2017, 04:32 PM   #3
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Buy a new CDU. Just get the printed circuit type without expensive lights and casing.
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Old 19-09-2017, 06:18 PM   #4
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Measure the voltage - are you getting full voltage from the CDU at the terminals?
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Old 19-09-2017, 07:41 PM   #5
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Quote:
Originally Posted by Suzie View Post
Measure the voltage - are you getting full voltage from the CDU at the terminals?
Thanks - must admit I don't know what full voltage should be, and had assumed that it probably wouldn't be sending all that much out until the split second when the switches throw.

I had another little mess around with it and can only assume it's a cabling issue. Now there are times when it doesn't throw at all (the lights stay on which I guess means there's no complete circuit) and other times when all points work perfectly.

So it can't be low on power.

I had started an RMA but I think I'll cancel it as it looks like I need to troubleshoot cabling a bit more.

Thanks for all the suggestions.
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Old 20-09-2017, 02:47 AM   #6
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Do a check with your wiring first. It sounds a bit like a connection where it is kind of connecting but sometimes it is not connecting. It wires are too thin it is possible to have burnt one out. Check switches to see if they work OK, but by the way yo suggest, it is something to do before the current gets to the switches as the CDU light shows it has charged OK.
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Old 20-09-2017, 08:41 AM   #7
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I would remove the CDU and set up a test circuit for it on the bench.

This would prove the power supply, the CDU, the switch and the point motor. Then you can best guess where the problem lies, CDU or layout.

I would be hesitant to put a meter across the output as the discharge may damage it (the meter).
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Old 20-09-2017, 04:37 PM   #8
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Thanks all.

Looks like I have a resolution, everything's working as before now.

I think it was just a bad connection between the CDU and the common return wire. I removed it, exposed a bit more inner cable and replaced it, and everything's working.

I'm used to working with data cabling where usually stuff either works or it doesn't. The concept of something working 'a bit' when there's an issue is totally alien to me!
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