STX-16803 PRODUCING FRAMES WITH NO SIGNAL

Discussion in 'STX and STXL Series Cameras' started by Max Whitby, Aug 31, 2019.

  1. Max Whitby

    Max Whitby Standard User

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    For the past year my STX-16803 has been a delight to use, solid and reliable… until last night! I attempted to take some flats, but when I captured an image using either TheSkyX or CCDOps all I see is a blank frame. Here are the symptoms in more detail:

    1) No problem connecting to the camera, controlling temperature, exposing and downloading images.

    2) The shutter is definitely opening (I shone a torch down the OTA to check and can clearly see the CCD revealed during exposures).

    3) The histogram on the blank frames I am getting shows a very weak signal around 800 ADU, but this does not vary with length of exposure or light level.

    4) I have tried updating the camera's firmware, rebooting the controlling PC and power-cycling the camera itself multiple times, but the problem remains.

    Here is a link to download a representative FITs file from the camera:

    https://www.dropbox.com/s/uheg21qz0hxwegj/Test_Luminance_1x1_20.000secs_-25.75C_00031277.fit?dl=0

    Darks and bias frames look exactly the same.

    I will be most grateful for any thoughts or suggestions please?

    regards from Northumberland

    Dr Max Whitby
    +44 7971 962694
     
  2. Colin Haig

    Colin Haig Staff Member

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    Dr. Whitby, thanks for such a thorough report.
    Would you mind uploading a BIAS and perhaps 60second Dark frame as well (preferably taken with CCDOPS)?
    The serial number would also be helpful.
    I believe you've had a hardware failure of some kind, and that it will lkely have to come in to @Bill for service.
    It's a long weekend here, but a couple of us check for messages.
     
  3. Max Whitby

    Max Whitby Standard User

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    Thanks very much for the swift response Colin, particularly on the long weekend. Here are links to download a bias and a 2 second dark:

    https://www.dropbox.com/s/rk3d57uoombolkw/TestBIAS_1x1_0.000secs_-11.40C_00031282.fit?dl=0

    https://www.dropbox.com/s/n9w2eln8s7xlrv4/TestDARK_1x1_2.000secs_-2.66C00031281.fit?dl=0

    I do not presently have access to the camera, so cannot take a longer dark.

    I fear you are correct in your diagnosis and I will need to ship the camera to Lompoc next week.

    Have a relaxing holiday.

    regards from the UK

    Max Whitby
     
  4. Colin Haig

    Colin Haig Staff Member

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    Thanks, these are fine, and I see all of them are similar, no hot pixels, low level noise around 800 ADU.
    Do you have any clues as to what may have happened? Power outages, lightning strike, anything unusual?
     
  5. Max Whitby

    Max Whitby Standard User

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    Thanks again Colin.

    No unusual power events to my knowledge. The camera was taking beautiful images the previous night. It remained on the telescope in my fixed observatory and the cabling was not changed.

    Three possible factors come to mind:

    1) I have recently been experiencing some partial frosting of the sensor (which typically cleared in the first hour of imaging) and was planning to bake the desiccant plug to correct.

    2) Immediately prior to the failure I pointed the OTA downwards (an unusual configuration) to take the flats using an electroluminescent panel near the floor.

    3) Earlier in the day I connected the camera to CCDOps for the first time in many months to check the serial number.

    regards from the UK

    Max Whitby
     
  6. Max Whitby

    Max Whitby Standard User

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    Here is the camera serial number.
     

    Attached Files:

  7. Doug

    Doug Staff Member

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    Looks like the A/D converter is seeing no signal from the sensor. Could be an electronics problem, or possibly there's something up with the CCD chamber. Make sure it isn't super wet in there; if it is do a desiccant recharge right away, let it sit for 24 hours, and then try again. Otherwise it may have to go to @Bill for service.
     

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