I opened up the timer tonight and adjusted the potentiometers as outlined by Ken and Rick and everything works perfectly - most of the time! I also checked the contacts on all the cables and everything is clean as a whistle. Interestingly, after getting the adjustments made so the timer matched my iPod timer on 68F, I realized as I starting putting it all back together that the problem seems to be in the rotator switch itself! When I pull down on it (toward the base of the unit), it runs normally; push it toward the top of the unit and the film side runs fast. This action does not affect anything else. Other than replacing the switch, any ideas on how to correct that? If I keep having the problem, I will talk to Calumet as several of you suggested. Thanks again!
I've yet to see that symptom, Michael, so I'm just speculating here.
Originally Posted by mmcclellan
Since the rotator shaft is by nature exposed to external forces, any chance that a knock in the past - perhaps in the dark - could have cracked the solder joints that hold it to the "motherboard?" It seems from what you describe that perhaps an electrical connection is sporadically failing to make proper contact.
I suppose it could also be a failed contact within the switch itself. But I would be more likely to discount dirty or corroded switch contacts, as the act of using the switch normally should keep those clean enough, I would think.
In any case, if you can localize the problem to the switch in question, then perhaps it's fixable by either Calumet, or someone local to you (television repair shop?) who is experienced with circuit boards and has the proper tools.
A replacement switch can't cost too much. And given the wonderful utility of these units, I'd think be well worth it. I know I couldn't do without mine. Sets of identically exposed prints* always process out identically for me. I love the thing.
* I also use the Zone VI Compensating Enlarging timer. Another fine piece of equipment that has always worked as advertised.
"There is very limited audience for the arty stuff, and it is largely comprised of other arty types, most of whom have no money to spend because no one is buying their stuff either. More people bring their emotions to an image than bring their intellect. The former are the folks who have checkbooks because they are engineers, accountants, and bankers—and generally they are engineers, accountants and bankers because they are not artists."
— Amanda Tomlin, Looking Glass Magazine, 2014
Thanks for the suggestion! I'm a total Zone VI "junkie"so really want to get this right! I was thinking the same as you and will follow up as you suggest. Thanks again!
I would try some contact cleaner as a first try. Dirty switch contacts are, statistically, the most likely problem. Although one might think it, exercising the switch won't clean dirty oxidized contacts - at least not for long.
If the switch is soldered to a circuit board, and the collar of the switch is not screwed down to the timer's case - then the connection between the switch and the pc board may have broken, as Ken has mentioned. This is especially true if the circuit board is single-sided. What cracks isn't the solder joint but the connection between the land (the round doughnut of copper foil where the 'bump' of solder is) and the trace (the long skinny bit of copper foil that connects to the land). With a 10x loupe you should be able to see the break when you flex the switches shaft. If the land has lifted from the board then the fix is to solder a bit of wire from the land/switch pin to the place where the trace goes to, thus bypassing the crack. Don't try to solder the land back to the trace - the solder joint will just crack open again.
The next likelyhood is that the switch is broke and needs replacing. If you can post a photo of the switch I may be able to point out a possible replacement.
Wow, I've just learned a bit more about keeping this timer going. Like the DC-9 of timers, or VW bug.
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