Durst Auto 707

Doylefotografix · Feb 2, 2020

I live in the uk and had my enlarger stored over winter but the damp has ruined the circuit boards. Now I only use it for BW work and use it for 6x7. Now rather than just bin it as it’s perfect for me and have all carriers etc , I was hoping it would be possible to just bypass all the circuitry and hook the lamp up to the 12v power supply which still works. I could put a timer inline and just use it like that. Any thoughts from you wizards out there ????

AgX · Feb 2, 2020

How can moisture ruin circuit boards?
There is no iron except for screws and other mechanical parts. Copper will deteriorate only in aggressive atmosphere, moreover the copper tracks or wires are typically either tinned or laquered. Dust and mould could be washed/wiped off.
One may argue on laquered capacitators or even the boards having got higher moisture content by diffusion, but that is something for guessing or metering.
What am I overlooking?

mpirie · Feb 2, 2020

I can't see any problem with wiring the lamp up to a suitable power supply and then using a timer to switch the PSU and lamp on and off.

After all, that's all an enlarger is.....just a lamp shining through the negative and lens to project an image on the baseboard. People are looking at doing similar things with LED's now that some electronics and lamps are no longer available/repairable.

If you're competent with electrical work then go for it and keep an eye out for replacement circuit boards, to allow a return to full functionality.

Personally, i wouldn't make any irreversible changes, just in case you change your mind or decide to sell on.

Mike

Doylefotografix · Feb 2, 2020

AgX said:
How can moisture ruin circuit boards?
There is no iron except for screws and other mechanical parts. Copper will deteriorate only in aggressive atmosphere, moreover the copper tracks or wires are typically either tinned or laquered. Dust and mould could be washed/wiped off.
One may argue on laquered capacitators or even the boards having got higher moisture content by diffusion, but that is something for guessing or metering.
What am I overlooking?

Really?? Then maybe it’s not quite as bad as I thought. Maybe it’s something less serious ??? It would be great if I could find the problem. I have metered the output from the transformer but it just seems dead. Nothing lights up. And no one in the uk seems to repair

Doylefotografix · Feb 2, 2020

mpirie said:
I can't see any problem with wiring the lamp up to a suitable power supply and then using a timer to switch the PSU and lamp on and off.

After all, that's all an enlarger is.....just a lamp shining through the negative and lens to project an image on the baseboard. People are looking at doing similar things with LED's now that some electronics and lamps are no longer available/repairable.

If you're competent with electrical work then go for it and keep an eye out for replacement circuit boards, to allow a return to full functionality.

Personally, i wouldn't make any irreversible changes, just in case you change your mind or decide to sell on.

Mike

Thanks Mike for the reply !!

AgX · Feb 2, 2020

Unless the head has a fan or seperate indicator lights, the only thing you need is a 240V/12V AC/AC 100W transformer. Hang the lamp on this and hang the transformer on a timer or meter/time as Mike proposed, and forget about the Durst built-in power-supply/meter/timer.

Of course before that you should check the obvious things: blown lamp, blown fuse at the power supply, net wiring and such.

Doylefotografix · Feb 2, 2020

AgX said:
Unless the head has a fan or seperate indicator lights, the only thing you need is a 240V/12V AC/AC 100W transformer. Hang the lamp on this and hang the transformer on a timer or meter/time as Mike proposed, and forget about the Durst built-in power-supply/meter/timer.

Of course before that you should check the obvious things: blown lamp, blown fuse at the power supply, net wiring and such.

ok. Here’s an update. Totally stripped it down and cleaned brushed everything. Turned it in and it came back to life. 100%. Maybe a connection problem. At least I know now that when it’s in it’s a runner. I will just have to find where the dodgy connection is. Thanks for all your help as it would be so sad to consign such a sweet enlarger. I do love it x

AgX · Feb 2, 2020

Connectors may develop corrosion at the contact points. I mean something that would not harm the board as such, but could be a trouble at these very points. Dis- and re-connecting, maybe added with application of a bit contact-cleaning fluid may be an approach. Also there may have been damp dust that shortcircuited something. Thus as indicated first look at the obvious suspects.

Doylefotografix · Feb 2, 2020

AgX said:
Connectors may develop corrosion at the contact points. I mean something that would not harm the board as such, but could be a trouble at these very points. Dis- and re-connecting, maybe added with application of a bit contact-cleaning fluid may be an approach. Also there may have been damp dust that shortcircuited something. Thus as indicated first look at the obvious suspects.

Thank you

Durst Auto 707

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