View Full Version : Durst CLS 1840, 220 volt equipment problem

scott palmer
9-Jun-2017, 18:41
Okay, long story with, perhaps, a simple solution. Durst 8x10 with CLS1840 head and EST 1500 N, 220 volt, power source. Using a Philmore ST-3000 step-up, step-down transformer to power the EST 1500. Using a Gralab 451, 110 volt timer. The relay in the 1500 is set for a 110 volt timer. Turn the transformer and power source on and everything is wonderful. Fan works and everything seems to be ready. Turn the timer on and everything stays wonderful. Hit the timer button for an exposure and all hell rains down on the world. The transformer starts buzzing loudly and vibrating like a magic fingers bed. As it's buzzing, the lamp comes on, but does not respond to the timer settings or switching just stays on until the power is cut at the transformer. The same thing occurs if I switch the timer to 'Focus': transformer goes nuts and lamp stays on until the power is cut. This equipment is new to me and was supposedly working as designed when I picked the unit up. All fuses in the power source read good on a continuity test. The transformer is delivering the correct voltage at the receptacle. Switched out timers and had to same problem. Everything works, just not the right way. I spoke with J.J. at Durst Oregon. He said everything is connected properly. I have a lot of experience with repairing and restoring darkroom equipment, as well as vintage audio amplifiers. But this 220 stuff is new to me. There is nothing obviously wrong with the equipment or the connections. J.J. said that his only thought was that the power source may have a problem. But shipping it all the way up there is expensive, and I do much more complicated electronics work than this could require. Unfortunately, I don't know were to start with this mixed voltage set-up. Anyone have any thoughts on the problem?

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9-Jun-2017, 19:45
At first I thought this was the EST 1000N, but on closer reading I see you have the EST1500N. Is the EST 1500N something unique to Durst USA, I can't seem to find a schematic for that unit.

Ted R
10-Jun-2017, 09:17
This shows some confusing symptoms but 220V AC works just like 110V just bigger. Was this made in the USA or Europe? If Europe the wire color codes are brown=live, blue=neutral, green+yellow=earth. Perhaps it would be worthwhile to open up each unit in turn and verify that the live neutral and earth connections go where they should and that there are no polarity inversions or mix ups between neutral and earth.

10-Jun-2017, 10:03
After some more research it seems as if the EST1500N is not a Durst Phototechnik GmbH Bolzano/Italy product. I checked the Durst-PRO USA site and can't find the schematic or repair manual for that unit. I'd contact them for more information.
The picture of EST1500N on the Durst-PRO site looks a little different than what you posted. Maybe you have a newer or older model.

10-Jun-2017, 10:07
This is the Durst GmbH EST1000N schemiatic but I don't think it shares anything with your unit other than the initials EST in the name.

10-Jun-2017, 10:19
In USA there are two common 220 hookups.

I can't say anything about the EST1500N, but the Durst EST1000N uses #2 below. Not #1. I don't know anything about running it off a transformer.




scott palmer
10-Jun-2017, 11:21
Thanks so much for the responses. The unit is manufactured in the US. I haven't been able to find a schematic either. Also, I understand that 220 is the same as 110 in theory, I just don't understand why the malfunction seems to manifest through the step-up transformer, which vibrates and buzzes loudly when the timer button is pressed for exposure, or the switch is clicked to 'Focus'. Also, I can't figure out why the lamp stays lit, even after the timer exposure has expired. That seems like it might be a problem with the relay. I'm stumped. Additionally, the focus motor won't work properly either. But that is, as far as I can tell, completely unrelated to the lamp head. It's not even on the same circuit. However, the switch continuity tests good, but I can't get any power to the motor. The motor does work. It ran a couple times, but somehow independent of the switch. It seems to be in 'Lock' mode.

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10-Jun-2017, 14:40
Just a thought, are you running two switching power supplies in series? Sometimes that does not work so well.

scott palmer
11-Jun-2017, 15:24
No, just the one power supply. The only other equipment in the line is the step-up transformer, which was used for years with this enlarger. It's just that something has changed during the transport process. It was only a few miles, but I still needed a trailer and had to remove the head. But the head is attached with only four bolts. Not a big deal. But by the time I unloaded the unit and reassembled everything, all these problems cropped up. With the head, it's the introduction of the timer into the circuit that causes the problem, which doesn't make any sense to me. Plus, the focus motor, a 24 volt, DC unit is a big question mark as well. I can't find a schematic for it either. It's connected to the switch with Cat 5 cable, and I don't know how it's wired. So checking the circuit is no simple matter. The switch is good, but that's about all I'm able to confirm. It's all 110v, but how it's wired is a little weird.

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