Durst EST 450 Power Supply

[Sneetch]

Hi All,

I'm searching for a circuit diagram or maintenance manual for a Durst EST 450 power supply.
I had my new (second hand) Laborator 1200 running for about half an hour before the power supply went BANG! It's now in the care of a repair technician, but it would really help him if he could see a schematic.

I've searched the forum and some old threads make mention of one, so hoping someone still has one lying around ...

Thanks guys!

[Eric Woodbury]

Here's a similar page:
http://www.largeformatphotography.in...01-and-EST-450

And there are a couple of others, but with a quick look I don't find the schematic. I'm not familiar with this enlarger. What does the power supply power? Light, lifting motor, ...?

If it really went bang, that's usually a capacitor. Like a fire-cracker? Did it smoke, too, or smell horrible?

Lift the hood and see what it looks like in there. Exploded caps leave a 'chaff'. Smoke that smell wretched is usually a burnt circuit board. A shorted cap can do this or a hot resistor.

Is there a fuse, either external or internal? Did it blow?

Here's another interesting thread. They say it is a 24VDC 450W power supply (that's a fair amount of juice). You must keep clicking 'next' to see all the entries.

http://www.pairlist.net/pipermail/la...q2/018896.html

[Sneetch]

Here's a similar page:
http://www.largeformatphotography.in...01-and-EST-450

And there are a couple of others, but with a quick look I don't find the schematic. I'm not familiar with this enlarger. What does the power supply power? Light, lifting motor, ...?

Thanks for the reply! The power supply powers the light and fan on this model.

If it really went bang, that's usually a capacitor. Like a fire-cracker? Did it smoke, too, or smell horrible?

Lift the hood and see what it looks like in there. Exploded caps leave a 'chaff'. Smoke that smell wretched is usually a burnt circuit board. A shorted cap can do this or a hot resistor.

More a "zzzzzzt POP", I suppose. I did check for a blown cap but there were none apparent. A bit of a burning smell, but no smoke.

Is there a fuse, either external or internal? Did it blow?

The external fuse blew. Replaced it, it blew again.. :-(

Here's another interesting thread. They say it is a 24VDC 450W power supply (that's a fair amount of juice). You must keep clicking 'next' to see all the entries.

http://www.pairlist.net/pipermail/la...q2/018896.html

Yeah, I'm not all that comfortable with mains voltage, so handed it off to a repair agent who works on older equipment. But he's a bit stuck without a schematic at the moment. Although he seems mighty impressed with the Durst design and build!

[pierre506]

I bought a power supply from a factory only directly about USD 20 to be instead of the original one.
220v to 24v, 300VA

[angusparker]

By all accounts the EST versions are all fancy circuits and blow up frequently (so said Durst USA after it happened to me) but the TRA versions are far simpler and more stable. I’ve switched over.


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[fj55mike]

Hi Sneetch,
If you're unable to repair your EST, take a look at what I did when my AC1200 power supply went out: Link