Leica V35 Enlarger problem

[StefanJozef]

I've had my V35 for 5 years with no problems. Now the light starts flickering after about an hour, gets progressively worse until no light comes on. I've tried changing the bulb with no effect. It usually works again after a few hours switched off. I'm worried it won't come on again though. Anyone got any advice or solution? Is it a condenser problem? Is the skip the only solution?

 

[Lee L]

Sounds like it could be a problem with the lamp contacts. Heat could be causing parts to expand and lose the connection. Any way to squeeze contacts tighter? Also check the lamp contacts and other connections in that circuit for tightness or corrosion.

If you have corrosion, check out Caig products. Not cheap. Deoxit for cleaning and preventing oxidation, ProGold and ProGold XL for maximizing current flow, with the XL designed for higher current and heat like tube/valve gear. I can't speak to local availability for you. It's a US product.

Lee

 

[Nicholas Lindan]

As Lee said, this sounds like a loose connection.

I wouldn't put anything on halogen lamp contacts - they run too hot for contact cleaners. I'm very skeptical of expensive contact treatments - I did an evaluation for a client that had trouble with contact dirt and found a simple mixture of mineral oil and isopropyl alcohol worked better than any of the expensive brands on the market, except, of course, the cheap Radio Shack product made from mineral oil and alcohol. Some of the products are worthy of http://www.machinadynamica.com/machina31.htm, http://www.machinadynamica.com/machina5.htm.

Does the lamp start to flicker after: 1) the lamp has been on for one hour; or 2) after the enlarger has been on for one hour with the lamp on for the usual printing?

If it is lamp time then you should probably just replace the lamp holder and tighten/replace the clips that attach the wires to the lamp holder.

If it is enlarger time then the problem may be in the base with the transformer, though again, the lamp holder is the likely culprit.

 

[Lee L]

Nicholas has tested the products, which I haven't done.

Just as info, though, the higher heat Caig product has changed names, to Caig DeoxIT Gold GxL, and claims stability from -45 through +310 Celsius. I don't know if the MR16 (correct for the V35?) sockets would exceed that or not.

Lee

 

[StefanJozef]

Thanks for the advice. I can't see any corrosion at all. It starts to flicker after the enlarger has been on for about an hour using the lamp only when printing or doing test prints. After about an hour the lamp won't come on. I have noticed the wiring from the timer to the enlarger condenser leaves a lot to be desired. Both ends have been joined by just intertwining the 3 separate cables and covering with insulating tape. Looks a bit dodgy. I'll take that apart and do it properly and see if that makes a difference.