Is this normal?

narcosisnz

Hi All,

I received a replacement ASI1600mm Pro because my first one had a faulty sensor. I ran some darks today and then integrated these in PI the result looks good but there is a dark strip at the very top edge of the calibrated frame. Is this normal? (see attachment)

20 frames, 139 gain, 21 offset, -20 deg, 60sec exposure.

(Note: I have used ASICAP and SGP for acquiring darks and the same dark strip is there when stretched in PI)

Here is a dropbox link to some fits files used in the creation of this.

https://www.dropbox.com/sh/ecyaui3knvc53k1/AAD1fPlS90IL2eaiu_s_bj66a?dl=0

dark edge.png

Kind Regards

narcosisnz

Dear Sam or Sean,

Do either of you guys have any thoughts on this? Is this normal for a 60sec Dark, 139/21 -20deg? Am I doing something wrong? Or do I have a sensor with an issue? I have seen subs taken from a different ASI1600 with same parameters which do not exhibit this dark edge.

Kind Regards

Support@ZWO

narcosisnz wrote:
Dear Sam or Sean,

Do either of you guys have any thoughts on this? Is this normal for a 60sec Dark, 139/21 -20deg? Am I doing something wrong? Or do I have a sensor with an issue? I have seen subs taken from a different ASI1600 with same parameters which do not exhibit this dark edge.

Kind Regards

Oh, it's not a big problem. It's a driver issue, we will fix this problem in next version of ascom driver.

narcosisnz

Sean.Wang wrote:

Oh, it's not a big problem. It's a driver issue, we will fix this problem in next version of ascom driver.

Hi Sean, thanks for the feedback. I have a few questions on this then.

Why would the example from my friend not suffer from this when he is running the same version of windows as me, sequence generator pro, same zwo drivers as me?

Why would my original camera not suffer from this? I have not changed computer or drivers.....I just got a replacement camera.

Other things I have tried are:

Different USB ports on my PC

Different USB speed settings in the ASCOM camera driver

Different power supply (I used a 12v Powerpack to eliminate my AC/DC power supply)

Different computer (I have a second PC already setup so I tried on that one)

Different gain and offset settings

Different integration settings in PixInsight

One thing I have not done is connect my friends camera to my computer to my computer to generate some subs. But for me unless you can tell me why there might be these differences this would be the next thing I try.

I look forward to your thoughts.

Kind Regards

narcosisnz

Hi Sean,

Do you use ASCOM for the driver selection in ASICAP? I mentioned in my original post that I checked by taking some frames in ASICAP and these too exhibited the same problem.

I have done more investigation on this and i believe it has something to do with the TEC cooling. When I'm cooling I get a lot of bands/lines in the sub...i think I have read somewhere this was a known issue. Is there a fix for this?

Then today I decided to take a 60sec dark frame without the TEC turned on the result was surprisingly better...obviously a different signal due to the sensor being warmer but there was no dark band at the top. Can you please tell me how to fix this or have this fixed if as it seems to be a TEC/Fan related problem.

Kind Regards

Jamie

narcosisnz

Dear Sean and Sam,

This is my last troubleshooting report, I do not know anything else I can test. I think I have now ruled out any PC, cabling, power, drivers (ascom and native), software, usb and environment possibilities. The only thing left is the camera itself.

I had a friend come to my home today and brought his ASI1600MM Pro. We plugged it into my PC and ran some comparable 60sec dark subs, exactly the same as I have been doing with my camera. As you can see from the photo there is no problems with his camera running on my machine, yet my camera taking subs on his PC still has the dark band at the top and multiple lines for a period of the frame (as you have seen before in my previous troubleshooting reports).

I think this would rule out the ASCOM driver and/or native driver correct since my friends ASI1600MM works perfectly on my computer?

I also bought a new USB 3.0 male A to male B cable today, this did not make a difference. I also tried a 3rd power source, this also did not make a difference.

Just so you know, I found a Customer FW updater tool on your forum For the ASI1600MM-C (I know not the pro), I ran this so I could show you the current firmware version and FPGA version…..please note I did not run any of the update functions as the files I found were for a different model of camera, this was for FW and FPGA versions reference only.

Is there anything I can do to get this camera working correctly? Or does it have to be returned to the retailer?

Support@ZWO

Hi Jamie

Our engineer is working on it. We will help you solve this issue as soon as we could.