Chromega D burning bulbs

Discussion in 'Darkroom Equipment' started by 3e8, Aug 5, 2013.

  1. 3e8

    3e8 Member

    Messages:
    71
    Joined:
    Oct 28, 2008
    Location:
    Maryland, US
    Shooter:
    4x5 Format
    I have a Chromega D2 that I put a dichroic head on a few years back. Lately the prints were getting less sharp, and the cooling fan seemed to be on the way out as it was vibrating more than usual. I replaced the original fan with this one, which matches the specs of Omega's recommended replacement quite closely. I got it wired in fine, but as soon as I powered the unit back up, the fan cam on, but the bulb burned out immediately. There was significant corrosion on one of the pins, so I figured the socket might be going bad. I replaced the socket today, and it's still burning out bulbs. Has anyone had this problem or have any suggestions?

    Thanks,
    Bryan
     
  2. Neal

    Neal Subscriber

    Messages:
    1,638
    Joined:
    Dec 3, 2004
    Location:
    Chicago, Wes
    Shooter:
    Multi Format
    Hi Bryan,

    Make sure you are still getting 24V AC to the bulb. Things might have gotten crossed up during repair.

    Neal Wydra
     
  3. Mark Layne

    Mark Layne Member

    Messages:
    919
    Joined:
    Jun 9, 2003
    Location:
    Nova Scotia
    I had a problem with bulbs burning out before their time and an electronics friend of mine dropped the voltage somewhere going from the timer but your problem seems to be somewhere else
    Mark
     
  4. brucemuir

    brucemuir Member

    Messages:
    2,265
    Joined:
    Dec 25, 2007
    Location:
    Metro DC are
    Shooter:
    Multi Format
    I was going to suggest the socket because those ceramic things are notorious for corroding into dust
    Luckily they are easily replaced.

    Sounds like a short somewhere but I am not someone to troubleshoot electrical problems.

    I will follow this post and please keep us posted because I did the exact conversion you have done and any knowledge is golden.
     
  5. Gerald C Koch

    Gerald C Koch Member

    Messages:
    6,474
    Joined:
    Jul 12, 2010
    Location:
    Southern USA
    Shooter:
    Multi Format
    Two more possibilities; vibration and current surge.
     
  6. brucemuir

    brucemuir Member

    Messages:
    2,265
    Joined:
    Dec 25, 2007
    Location:
    Metro DC are
    Shooter:
    Multi Format
    That entire socket thing that is white clay/porcelain of some sort can corrode and short out. I can barely remember how this is configured but did you replace both the socket and the bulb or just the bulb.

    If you search the archives here there is some very useful threads and at least one of them has photos of this part of the Super Chromega II head.
     
  7. RPC

    RPC Member

    Messages:
    639
    Joined:
    Sep 7, 2006
    Shooter:
    Multi Format
    The new fan could have somehow resulted in a voltage regulation problem in the power supply.

    I would try going to classic-enlargers.com and the help forum. Harry Taylor there is an expert on Omega enlargers.
     
  8. DREW WILEY

    DREW WILEY Member

    Messages:
    4,970
    Joined:
    Jul 14, 2011
    Shooter:
    8x10 Format
    Corrosion inside the socket will definitely do it. You should replace this. Cooling is an issue, and as you probably already know, you should never
    let your fingers touch the reflective part of the bulb. Best to wear cotton gloves. Another serious problem which isn't generally known is that a
    lot of bulbs nowadays are sheer crap. You use an ELC bulb probably. Try to find Japanese made Ushio or some older US made inventory. Lots of
    these el cleapo bulbs coming out of China won't last very long at all.
     
  9. brucemuir

    brucemuir Member

    Messages:
    2,265
    Joined:
    Dec 25, 2007
    Location:
    Metro DC are
    Shooter:
    Multi Format
  10. brucemuir

    brucemuir Member

    Messages:
    2,265
    Joined:
    Dec 25, 2007
    Location:
    Metro DC are
    Shooter:
    Multi Format
  11. RPC

    RPC Member

    Messages:
    639
    Joined:
    Sep 7, 2006
    Shooter:
    Multi Format
    The OP said he replaced the socket but it is still burning out bulbs.