STXL-11002M, all drivers and firmware up to date. Taking 20 minute darks, 1x1, -35C. First 14 darks OK, next four show a progressively longer and darker streak from top to bottom on left side. What could it be? This did not happen with subsequent 2x2 darks, 10 minutes, -35C on same night. I have attached the first (#15) and the worst (#17) images. Thank you. Alan
https://1drv.ms/u/s!AtHc9a_3_v7tgsQ3fkUm-WMw9wNKeA https://1drv.ms/u/s!AtHc9a_3_v7tgsQpgSulMfR_uTEluw https://1drv.ms/u/s!AtHc9a_3_v7tgsQlGb7jZ4aI9mx6GQ https://1drv.ms/u/s!AtHc9a_3_v7tgsQifqv6z6Hjed0uiA
Hi Alan - thanks for uploading the darks. This is unusual - not seen this before. Doug may want a few bias frames as well, so we could determine possible cause.
Thank you for your reply. The links above are darks 15-18 in a set of 18, 20 minutes, 1x1, -35C. I will attach the preceding darks in the set, 11-14, for comparison. I will also attach several bias frames, 1x1, -35C, taken previously on the same night. https://1drv.ms/u/s!AtHc9a_3_v7tgsQfViNt0lIseSa66A https://1drv.ms/u/s!AtHc9a_3_v7tgsQjQquMQzwzpg4Qcg https://1drv.ms/u/s!AtHc9a_3_v7tgsQyiJ4Qf-ZUuLuVuw https://1drv.ms/u/s!AtHc9a_3_v7tgsQxHsM3_n488XIYUg Bias: https://1drv.ms/u/s!AtHc9a_3_v7tgsNe9KIhUQjmYNZqXw https://1drv.ms/u/s!AtHc9a_3_v7tgsNnWrRq0rsTFVQwtQ https://1drv.ms/u/s!AtHc9a_3_v7tgsNrISIn8d4ImApgcQ https://1drv.ms/u/s!AtHc9a_3_v7tgsN8voZsP20qCHo4-Q
Thanks Alan. Doug will need to have a look. I see the effect in the Bias frame as well. (eg the last attachment it is quite obvious).
The biases were a set of 25 - I included numbers 1, 9, 17 and 25. I wonder if the effect is time dependent. Focal length 540, Aperture 106.
Looks like something in the electronics is starting to fail. I expect it's one of the regulator circuits that powers the horizontal clock drivers. Could be the drivers themselves, but the ripples I'm seeing suggest poor voltage regulation. Best guess would be a bad filter capacitor. What is your camera serial number?
Built in December 2015. All the test data looks good. This must be a random component failure. Sorry for the trouble. Please contact Bill @ SBIG Service & Repair, bill@sbig.com to get that fixed.