Nuarc 3140 Trouble shooting

[rmonks]

My older 3140 the one with four legs. It was working fine last week and this week i have a problem. It pulls vacuum , but does not expose. I can trick it to think the lid is down and the lamp comes on but not as bright as usual.  It usually has a loud transformer kicking in sound but not now. And there is not counting down on the display. Anyone know where to start looking for the problem. Thank goodness i have an old National exposure unit  for backup.

[Frog]

Have you called M&R?

If Rich doesn't chime in here, (or even if he does) you may also find some help at the M&R Forums http://forums.mrprint.com/

[blue moon]

My older 3140 the one with four legs. It was working fine last week and this week i have a problem. It pulls vacuum , but does not expose. I can trick it to think the lid is down and the lamp comes on but not as bright as usual.  It usually has a loud transformer kicking in sound but not now. And there is not counting down on the display. Anyone know where to start looking for the problem. Thank goodness i have an old National exposure unit  for backup.

I had a similar problem few months back (same four leg 3140). There was a burnt wire on one of the boards. I just cut it and put another connector on it and it was back to normal. You will have to open the bottom. Check an orange wire that is going from the right middle, then to the back and connecting two boards on the left side. From what I remember it was the common power for the relays. Again, if I remember right, there are two relays, one of them is to get it started and the other to keep it going. In my case the light would start, but would not stay on.
If the light will not start, you can manually push the relay and see if you can get it going. You do have to jump several safety switches and work on a live circuit with pretty high voltage.  Also as an FYI, turning the power off on the control panel does not kill the circuits, so make sure you unplug it if you want ti dead!
call me if you need any more help, not sure I will have time to tear ours apart,  but I might be able to give you some pointers on where to look and what to do. M&R tech could not help much, he said there was a problem with the electronics in the bottom and that it is most likely a loose connection. I should go and check all of them to make sure non fell off. In the end he was right as one was burned!

pierre

[rmonks]

Pierre: thanks that sounds very logical, and may be my problem. It will be a day or two before I can open it up and check it out. Yeah! it sounds like some high voltage something is not getting the juice it was, because there is a definite change in the sound when it kicks into the exposing phase of the operation.

[244]

My older 3140 the one with four legs. It was working fine last week and this week i have a problem. It pulls vacuum , but does not expose. I can trick it to think the lid is down and the lamp comes on but not as bright as usual.  It usually has a loud transformer kicking in sound but not now. And there is not counting down on the display. Anyone know where to start looking for the problem. Thank goodness i have an old National exposure unit  for backup.

I had a similar problem few months back (same four leg 3140). There was a burnt wire on one of the boards. I just cut it and put another connector on it and it was back to normal. You will have to open the bottom. Check an orange wire that is going from the right middle, then to the back and connecting two boards on the left side. From what I remember it was the common power for the relays. Again, if I remember right, there are two relays, one of them is to get it started and the other to keep it going. In my case the light would start, but would not stay on.
If the light will not start, you can manually push the relay and see if you can get it going. You do have to jump several safety switches and work on a live circuit with pretty high voltage.  Also as an FYI, turning the power off on the control panel does not kill the circuits, so make sure you unplug it if you want ti dead!
call me if you need any more help, not sure I will have time to tear ours apart,  but I might be able to give you some pointers on where to look and what to do. M&R tech could not help much, he said there was a problem with the electronics in the bottom and that it is most likely a loose connection. I should go and check all of them to make sure non fell off. In the end he was right as one was burned!

pierre

You are correct. There is probably a bad connection or burned wire by the bottom boards. These units were made prior to us purchasing Nuarc and they used a lighter gage wire than the ones we build now. FYI rmonks this is a capacitive circuit and even after turning off the power there can still be voltage. Disconnect power and then short the capacitors to ground to be sure or wait at least 20 minutes before touching any wires.

[rmonks]

Come to think of it I did smell something that smelled like wiring getting hot or burning a few days ago. Thanks

[inkbrigade]

Call Ron Hopkins at Nuarc. That guy knows everything and is super cool!

[rmonks]

I found my problem, I removed the cover from the left side of the electrical component compartment, and there is a long brown coil looking thing with a wire bolted on each end. One of the wires was not attached, Strange thing is I cannot find the bolt and nut that held it on. I replaced the bolt and nut and works fine.