Gralab 500 series Timer (Blown Up - but there is a good news ending!)

jvo said:

ah, if i remember correctly, the rh designs timer (a wonderful machine), had a 220/110 switch!

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Oh..mine doesn't state this. I think I've learnt my lesson ...Will stick with what's written on the unit

The parts you blew up are mounted on the side of the circuit board you can't see in the photo posted. I can tell by looking at the back that you have a basic transformer/regulator power supply that's doing your ac/dc conversion. If you're lucky, the voltage regulator (or regulators) that are in the DC supply acted as fuses when it smoked, leaving everything else intact. Get those replaced if so, maybe a couple diodes or resistors, and you're off and running. If you're unlucky, you also fried everything inside the thing that runs on 5V and possibly burned up the LED displays as well. In that case, just buy another one.

And burned up parts won't always be visibly burned but if you heard a bang, and smell the smell, it released the magic smoke from something so chances are really good that something is physically damaged. Also, when things get physically damaged, there's often additional damage you can't see.

Hi thanks Eurekaiv -

That's helpful. Still got to take it around to an electrician. As far as I can tell the higher end Gralab 565 series aren't common or even much in circulation these days (especially in the United Kingdom where they are way more obscure than the USA).

In the meantime, the students have discovered using red acetate gel sheets over their mobile phones with a stopclock timer works very well.

RJ- said:

Hi thanks Eurekaiv -

That's helpful. Still got to take it around to an electrician. As far as I can tell the higher end Gralab 565 series aren't common or even much in circulation these days (especially in the United Kingdom where they are way more obscure than the USA).

In the meantime, the students have discovered using red acetate gel sheets over their mobile phones with a stopclock timer works very well.

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I can set my iPhone 7 to a red darkroom safe screen with three taps. Three taps back to the normal screen.

RJ- said:

Wow mshchem ~ that really was a chariot on fire. I guess this is why public places have PAT tests unlike home dwellers and darkroom users!

I opened the Gralab - it smells of polymerised toast although it looks surprisingly non toast. The circuit board looks unmarked ...is it possible maybe the blown parts along the circuit spike surge not have destroyed it beyond repair..

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The top capacitor in the middle of the picture looks like the top is bulging up - a sure sign of toasted cap - yellow an black thing.
Replace both of those - or get someone to do it and try back on 120 supply, may be the only fault but could have caused more down the line? worth a try.

Sirius Glass said:

I can set my iPhone 7 to a red darkroom safe screen with three taps. Three taps back to the normal screen.

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Ahh....one of the students had a phone which did this and then a mobile phone alert came on and suddenly it was back to normal LED white light screen in middle of printing.

Thinking a no digital policy in the darkroom with the exception of www.digitaltruth.com paper scribbles

Steve906 said:

The top capacitor in the middle of the picture looks like the top is bulging up - a sure sign of toasted cap - yellow an black thing.
Replace both of those - or get someone to do it and try back on 120 supply, may be the only fault but could have caused more down the line? worth a try.

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It's not looking good is it. Thanks for the clarification about the capacitors. I'll find someone who might be able to swap them over and see what happens!

RJ- said:

It's not looking good is it

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It's not looking bad, really. I don't see the bulging. Which doesn't mean it isn't there - it may or may not. But it's not particularly bad in any case (I've seen and replaced hundreds of bulging caps). Neither does it (if it's bulging) explain very well an entirely non-functioning machine, especially in the light of it having been connected to the wrong mains.

Just get someone with decent working knowledge of electronics to have a look at it.

If you extinguish electrical fires with a water hose,
you could electrocute yourself , you should use a foam extinguisher.

Well, instead you just could pull the mains cable. Chances are that then you won't need an extinguisher at all...

I never thought thought was possible after blowing up my trusted Gralab 545 timer by accidentally putting 220volt through its 120volt wiring.

{threads combined by moderator}

I took the advice of the guys here and figured out a technician who could tackle it. My technician found it was just the capacitor side and the rest of the unit still working. Not only did he repair it, but also converted it to 220volt for permanent UK use.

Yay! Thanks for the help - I was so close to binning it. Now it's back in the darkroom for the students to make use of instead of counting 1 hippopotamus 2 hippopotamus 3...

Inspiration for anyone in love with these older bright dimmable LED timers ..worth hanging onto!

Great news.
I've combined your two threads!

Hi, I hope this finds you all well. Im having trouble to connect the timer Gralab 545 to my Durst CLS 450 enlarger. I could find any instructions online, even check the manual but still don't understand how it works to the enlarger. The lamp is not turning off, I may been connecting the cables wrong. Would you please help me? best

Check which plug the enlarger is plugged into A or B, on the side, then check the settings for outlet controls on the front, upper right side. Best to plug the enlarger in outlet B and set the front outlet B on and then try changing the TIME and Overstoke Time.

Giovanna Lanna said:

Hi, I hope this finds you all well. Im having trouble to connect the timer Gralab 545 to my Durst CLS 450 enlarger. I could find any instructions online, even check the manual but still don't understand how it works to the enlarger. The lamp is not turning off, I may been connecting the cables wrong. Would you please help me? best

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Hi Giovanna

I have the instruction manual in English. Yes the manual assumes extra knowledge of interfacing the dual timer function to either 1 or 2 enlargers.
when the lamp is not turning off (yet is powered on in series with the Gralab 645, you depress the far left button on the upper right panel of buttons - just visible in the image uploaded in post #36. The override setting locks the lamp on easel/composition and then the buttons on the top right panel are used interchangeably for printing/composing and focussing.

Since your lamp is on, you have the correct A or B mounted circuit attached. You can use the footswitch which can reset the lock on lamp to <<OFF>>.

If that doesn't work, perhaps an image of your cable connections. Your lamp is on so you are already half way there and not much more before sorting.