V35 transformer broken?

[huubl]

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A few weeks ago I got a second hand v35 enlarger. Beautiful machine. After testing everything seemed to work excellently. Today I finished setting up my dark room and installed the enlarger. First time I switched the lamp on, everything still worked great. tested the autofocus, brilliant! The lamp was on for a total of not more than 5 minutes. One hour later, ... switched the lamp on again, ... nothing. Checked the wall outlet, OK. Put a new lamp in, nothing! Checked the current at the leads on the lamp house, no current! Fuse, OK. Opened the base unit, checked that the switch delivered current, OK. Transformer got current, but nothing came out at the 12 V end! Does this mean that the transformer is broken??? After many years of use, exactly at the time I finished installing a new dark room, the transformer blows??? I feel miserable...!!! Are these transformers still available? Or should I get a replacement transformer? What specifications?

Anybody has any suggestions???

Thanks in advance.

[NB23]

Mine had the same problem but I realized the light socket was burnt and so I changed it (total cost 5$). The bulbs get so hot it's possible it burned the wires over the years.

 

I am interested to know how you'll solve your problem as I have the same excellent enlarger and every info is worth gold.

 

Good luck

[huubl]

Mine had the same problem but I realized the light socket was burnt and so I changed it (total cost 5$). The bulbs get so hot it's possible it burned the wires over the years.

 

I am interested to know how you'll solve your problem as I have the same excellent enlarger and every info is worth gold.

 

Good luck

 

Thanks for your reply. It's not the wires, I think. They look OK. I used a small screwdriver with an inbuilt power indicator that glows if in touch with an active wire. They work well with 220V. Does anybody know if they're also sensitive for 12V? If they're not that may explain why the transformer seems broken. Of course that would still also mean that both my lamps are broken as well.

[marknorton]

The neon screwdrivers will not work at 12v.

 

You need to buy yourself a simple multimeter from a hardware store (say, €20) which will allow you to check the voltage going into the transformer, coming out and the continuity of the windings. A transformer is nothing more than 2 coils wound on to the same iron core; you should be able to measure the resistance of the primary winding (connecting to the household current) and of the secondary winding (which, if it is 12v will have much thicker copper wire).

 

You can also measure the continuity of the lamps, the wiring and the fuses. Take care though, and only do your continuty checks when it is disconnected from the wall socket.

 

A transformer like this is easy to source. It has to have the correct VA rating (power) and you'll want it to fit in the same space as currently. I assume there are no rectifiers in there so that the bulbs are fed from 12v AC? What is the rating information for the bulbs?

 

The more information you can post, maybe some pictures, the more I can help you.

[Irishimage]

I'v replaced the transformer in my V35 about one year ago,

reason was i had large variations in light intensity during exposure.

 

Now its in perfect working order.

 

I installed a Toroidal type Transformer with similar ratings to the original as size and design fitted perfectly into the limited space available.

 

You would need to be somewhat competent in electronics to do this yourself so i would prefer not to give to many details in an open forum.

 

Therefore it might be best to PM me if your require further information/details etc.

 

Noel

[huubl]

Thank you all for your valuable suggestions. Mark, thanks for the info on the multimeter. I borrowed one and found out that the transformer was OK. I'll see how constant it is in the coming weeks and if it proves unreliable I'll contact you Noel, to provide some details on the alternative transformer you installed. Nenad, you were right. The wiring near the lamp was completely burned. I installed some new leads and soldered them onto the lamp fitting, not a pretty job, but it works well now!

 

Thanks again, this is a wonderful helpful community!

[NB23]

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This is exactly what I suspected

 

For a neat job simply buy a new socket and tape the wires together and you should be good to go for another 20 years unless the transformer starts acting up (for which I want infos, just in case I need to change it one day).