Help with Durst CLS 1840

[rp_analog]

I need help troubleshooting this issue. The enlarger bulb will only burn at the warming rate. I have the main power unit, the Code ST1000N voltage stabilizer and the ECU 1000 control unit. I have checked all fuses and replaced the 1000wt bulb and socket. I have taken covers off the power unit, stabilizer and cord heads and find no obvious issues.


Backstory: I purchase the unit a few years ago and hauled it in a trailer from NJ to Ga. it sat in storage for three years. I recently installed it for the first time. The first time I connect everything and turned it on the lamp came on. I turn it off and flipped the head up to horizontal and the lamp then did not come on. I did not remove the top at that time and don’t know if was then burning at warning rate. The bulb may have been like that se in the socket, as I found evidence of some arcing and black carbon. I installed a new bulb and a new socket.

Any ideas on where to start?
Thanks!

[dsphotog]

I'm no expert, my first thought is the timer, and how it's connected.

[ic-racer]

Is the shutter opening and closing? The shutter makes a lot of clatter, so you should be able to hear it opening and closing. Or you can take off the UBEN Larabox piece and look up there. (CLS2000 shown but yours is likely similar)

[ic-racer]

According the the documentation the pre-heat on the lamp is only supposed to be 15V. Since my head runs from 240V, I have always had it unplugged when I access the lamp for safety, so I actually have never seen how much mine glows during pre-heat. I was always under the impression the lamp would not even glow at that low voltage, but I could be wrong.

Attachment 205502

[ic-racer]

I suspect you have checked the pins on your Siemens connectors. THREE pins to carry the current to the lamp. On my cable connector one pin had burned off, so I'm down to only two pins carrying the current (the 3 pins are all connected to single wire BTW).

[ic-racer]

Send a PM to me to get the service manual and schematics as a ZIP file.

[rp_analog]

I can hear a switch when I go from focus to off on the ECU The shutter in the enlarger head is not firing. The lamp fan
Is also not working. The up/down controls for the head and lens board are working.

[rp_analog]

All the pins and connections appear to be OK

[ic-racer]

The timer counts down OK?

[rp_analog]

The timer counts down OK?

Yes the timer counts down and I can hear it switch off in the power unit but nothing in the enlarger head.