RGH presents a black screen on capture or intermittant horizontal banding

Discussion in 'Legacy Models - Community Support' started by David Trotter, Mar 19, 2015.

  1. David Trotter

    David Trotter Cyanogen Customer

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    Last night I was starting a guiding run using a combination of STL6303e plus an RGH using Maxim DL as the guiding and capture software sitting on a windows 8.1 PC. All this is in a permanent setup.
    I had previously focussed successfully and test images were coming down fine from the main camera.

    On clicking capture to find a guide star, a 6 second image was taken after a six second auto dark, the image then went through the dlownload process but on completion I was presented with a pitch black screen.

    I tried this a couple of times. same result.
    I adjusted the exposure length and again tried and in this case on download there was a pitch black autoguider image but with what looked like interference lines appearing horizontally on the presenetd autoguider image, no stars.
    This has happened once before about 3 months ago and I thought it was a munted RGH so I used a replacement which worked fine up until last night .

    I shut everything down again, pulled out power cables then rebooted the PC, relaunched capture software, reconnected fine, cooled down the CCD to around minus 10 then tried again. Same result

    I then tried using the internal guide chip by turning off cooling and updating the camera settings switching to the internal chip for guiding rather than the external chip (RGH) and surprisingly I got the same issues once I recooled everything and tried again. Main CCD works fine.

    Any ideas? Cable or mechanical?

    Thanks
     
  2. Bill

    Bill SBIG Service and Repairs Staff Member

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    David,

    Was the RGH still connected to the camera when you tried the Internal Guider? If so, disconnect the RGH and try the Internal again. Have you ever recharged the desiccant plug in the RGH?

    -Bill
     
  3. David Trotter

    David Trotter Cyanogen Customer

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    Hi Bill

    I will check the internal chip tonight whilst the RGH is baking. I must admit I have never recharged the decissants before.

    Much appreciated
     
  4. Bill

    Bill SBIG Service and Repairs Staff Member

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    It's possible that the RGH may have some corrosion damage and therefore when connected to the STL, it's affecting the Internal Guider as well.
     
    Last edited: Mar 22, 2015
  5. David Trotter

    David Trotter Cyanogen Customer

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    I see. If so, is it likely to be repairable, and if not, what replacement RGH type options would be available that are compatable with an STL ?

    Thanks for the response
     
  6. Bill

    Bill SBIG Service and Repairs Staff Member

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    David,

    It's likely repairable, I'm pretty sure I have the potential replacement parts that might be needed.

    -Bill
     
  7. David Trotter

    David Trotter Cyanogen Customer

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    Thats good to hear. I will be sending 2 back, similar issue. I really must note to recharge decissant on a regular basis.

    Whats the process for returns for repairs. Is there a specific address?

    Thanks again.
     
  8. Bill

    Bill SBIG Service and Repairs Staff Member

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    Have you verified that the Internal Guider works with the RGH disconnected? Send me an email at work, bill@sbig.com, and I'll give you the details on sending them in. I'll be out Monday but will be back Tues.
     
  9. David Trotter

    David Trotter Cyanogen Customer

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    Thanks Bill
    Confirming the internal chip works fine with the RGH disconnected and I have dropped you a separate email re sending them in

    Thanks again
     
  10. Joseph Zeglinski

    Joseph Zeglinski Standard User

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    I'm a little late replying - since I originally posted using the "standard email program" to reply, which unlike Yahoo Groups, doesn't actually get delivered to the forum - to be heard, I should only reply directly from this forum.

    Not an expert, but I wonder if the main camera is getting “good and stable” DC power supplied.
    The STL is smart enough to perform a few “fallback procedures” on flakey or low power – like shutting down its cooler first, so it can still take main CCD frames before finally crashing, as the power falls to an even lower voltage level. See the write up about the power supply and the power LED indicator patterns.
    I would expect the guider RGH, or the internal guider, to be sacrificed before the STL finally gives up and shuts itself down for protection.
    Can you try a different supply – perhaps its AC power brick? Of course, loose power cable connections could do the same thing - though not likely to be repeatable with a different supply and its different power cable connection.
    BTW:
    Did you unplug the RGH cable, from the STL, when you tested the internal guider for the same problem? If not, a flaky RGH cable connection or bad DB pins. might cause random problems – especially as the scope moves around shaking cables. Certainly make sure the RGH “micro-DB connector” is screwed in straight and firm.

    But, that’s just my hunch.
    Joe Z.
     
  11. Bill

    Bill SBIG Service and Repairs Staff Member

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    Helpful suggestions Joe, low input voltage and a poor RGH connection are quick and easy checks. Historically, the Power Adapter is a low failure item, same for the RGH connector mounted in the camera. A failure of the power supply pcb would likely appear as a dead camera, or a "no response to power" type symptom. There have actually been cases of corroded RGH's , or bad RGH Cables, affecting the internal guider. A quick test, with no RGH or cable attached, will tell you whether it's the RGH or the STL.
     
    Last edited: Mar 22, 2015
  12. David Trotter

    David Trotter Cyanogen Customer

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    Hi Gents
    I have just finished doing some checks here. Calibrated the internal guider (RGH disconnected) then a slew to target, ran some test 5 minute subs and monitored both the internal guider behaviour and also the flashing lights on the STL.
    From what i can see the internal guiding is fine and the power supply is constant through the A/C brick which is the one I normally use.

    Thanks for adding thoughts Joe, always good to check.
     

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