robert_starbuck1 Posted February 3, 2008 Share Posted February 3, 2008 Yesterday my Chromegatrol (Cat#412-040) failed to turn off the lamp at the end of its timed interval and has since kept the lamp ON despite everything I have tried. (Of course, the master POWER switch still turns everything off.) My questions are: (1) Is this a problem common enough that others have experienced it and have any user-servicing suggestions as to a solution? (2) What is the cost of having Omega repair it - if they do any longer, if the fix will last, if it is "worth it", etc.? (3) Would the use of a regular timer (eg a GraLab 300 or, my favorite, the 400!) introduce a problem as to cooling since the Chromega II head's fan would not operate between exposures as with the Chromegatrol? Thanks! Link to comment Share on other sites More sharing options...
len_robertson Posted February 3, 2008 Share Posted February 3, 2008 Robert - You may find the answers you need on the wonderful Omega enlarger forum: http://www.classic-enlargers.com/cgi-bin/yabb/YaBB.pl?board=general Len Robertson Link to comment Share on other sites More sharing options...
robert_starbuck1 Posted February 3, 2008 Author Share Posted February 3, 2008 That is a WONDERFUL place...I'll check there! Thanks Link to comment Share on other sites More sharing options...
robert_starbuck1 Posted February 4, 2008 Author Share Posted February 4, 2008 Communication with Harry was very helpful. I had discovered that I already had an Omega SUPER CHROMEGA DICHROIC Power Supply (Cat. No. 412-021); an Omega Solid State Precision Timer (Cat. No. 461-012); an Omega Solid State VOLTAGE STABILIZER (Cat. No. 404-841); and a non-Omega Linemaster "Treadlite" foot switch - all connected together from another Chromega. Not only did it all work in place of the Chromegatrol, but ANY standard enlarger timer will also work by routing its power through the 412-021 power supply. So I now have the option of using a GraLab unit if desired. Thanks. Link to comment Share on other sites More sharing options...
robert_starbuck1 Posted February 4, 2008 Author Share Posted February 4, 2008 <div></div> Link to comment Share on other sites More sharing options...
gone fishing Posted February 4, 2008 Share Posted February 4, 2008 Robert-This happened to me recently and, after disconnecting the AC Line and removing the cover I found that the wiper-arm(s) on the decade switches were oxidized (probably from lack of "exercising" them by rotating through their positions). I used WD40 and a cotton swab to clean them (carefully - in order to prevent bending or twisting them) and the unit was restored to normal operation. Obviously I don't know if this is the case with your unit but the decade switches used in these units are susceptible to this type problem, particularly in humid environments. Hope this helps!Joel Edmondson Link to comment Share on other sites More sharing options...
robert_starbuck1 Posted February 4, 2008 Author Share Posted February 4, 2008 ...gonna try that...now where's my WD-40...? Thanks! Link to comment Share on other sites More sharing options...
robert_starbuck1 Posted February 4, 2008 Author Share Posted February 4, 2008 Joel - How did you possibly access the contacts within the rotary switches? They appear entirely sealed against a multi-solder connection to the circuit board. Puzzled...Bob Link to comment Share on other sites More sharing options...
gone fishing Posted February 5, 2008 Share Posted February 5, 2008 Bob - On the unit I have the contacts, other than the point which is selected at the time, are exposed enough to allow access. I don't know whether there are differing units over the life of production but most rotary switches I have seen appear similar with the wiper arms rotating to make the circuit through the decades. Usually the stationary "spring-type" contacts on the fixed wafers are the culprits as the result of oxidation forming on the contact points and units which are frequently rotated through the ranges don't seem to have the problem... Joel Link to comment Share on other sites More sharing options...
Amanda B Posted June 7, 2023 Share Posted June 7, 2023 Hello! I know this is an old post, but I have multiple Chromegatrol timers with this problem (timer stopped working, they just stay on). I wonder if Joel or someone could possibly take a photo of the decade switches that they cleaned so I know what I'm looking for? I can wield WD-40 and a Q-tip, but I know nothing at all about electronics. Thank you! Link to comment Share on other sites More sharing options...
john_shriver Posted July 6, 2023 Share Posted July 6, 2023 WD-40 is NOT suitable as a contact cleaner. There are specific electrical contact cleaners. Link to comment Share on other sites More sharing options...
Niels - NHSN Posted July 6, 2023 Share Posted July 6, 2023 Deoxit is often mentioned on vintage stereo forums. Niels Link to comment Share on other sites More sharing options...
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