Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

asi6200mm - 50% of the pixels are dead or stuck!

CMOS Equipment
  • Please log in to reply
15 replies to this topic

#1 v8vantage

v8vantage

    Sputnik

  • -----
  • topic starter
  • Posts: 31
  • Joined: 19 Feb 2021

Posted 02 December 2023 - 06:46 AM

Hi!

 

My three year old asi6200mm suddenly, and intermittently, started to deliver every second pixel as dead = 0 + offset in bin1x1. Running bin2x2 looks OK (not sure how the software binning in the camera is done, averaging or just adding):

 

Dead pixels.jpg

 

The issue is still intermittent, but the trend is bad - a month ago a simple reconnection of the camera would most often solve the problem. Today its almost impossible to get all the pixels and not only every second one.
 

I first noticed this when the humidity of the autumn came and the dew heaters kicked in, overloading the PSU - could low voltage to the camera damage it?

 

Or am I just experiencing a camera that is "worn out" - it has done at least 5000 hours...


Edited by v8vantage, 02 December 2023 - 06:47 AM.


#2 Fegato

Fegato

    Viking 1

  • -----
  • Posts: 551
  • Joined: 15 Nov 2018
  • Loc: Llanfynydd, Carmarthen, Wales

Posted 03 December 2023 - 02:34 AM

No idea I'm afraid, but as no one else has replied, I'd just say that I would write to ZWO and ask them if they know what it might be and whether it is fixable. I don't think a camera of that price should "wear out" after 3 years even with high usage...


  • PrestonE, Michael Covington, v8vantage and 1 other like this

#3 Jared

Jared

    Cosmos

  • *****
  • Moderators
  • Posts: 7,925
  • Joined: 11 Oct 2005
  • Loc: Piedmont, California, U.S.

Posted 03 December 2023 - 10:50 AM

“Worn out” camera is very unlikely. Any time I hear about intermittent issues like this, I automatically think communication issue. Try a different cable. If you are using a USB hub, try without the hub.
  • giorgio_ne and v8vantage like this

#4 Kevin_A

Kevin_A

    Surveyor 1

  • *****
  • Posts: 1,552
  • Joined: 22 Aug 2018
  • Loc: Belmont, Ontario Canada

Posted 03 December 2023 - 11:33 AM

Maybe the firmware in the camera has gotten corrupted. Contact zwo and see if the camera firmware can be over written since you said that all the cables are ok on the zwo forum. 
 


  • Michael Covington and v8vantage like this

#5 jdupton

jdupton

    Fly Me to the Moon

  • *****
  • Posts: 5,389
  • Joined: 21 Nov 2010
  • Loc: Central Texas, USA

Posted 03 December 2023 - 11:58 AM

v8vantage,

 

My three year old asi6200mm suddenly, and intermittently, started to deliver every second pixel as dead = 0 + offset in bin1x1. Running bin2x2 looks OK (not sure how the software binning in the camera is done, averaging or just adding):

 

Or am I just experiencing a camera that is "worn out" - it has done at least 5000 hours...

   This does look like a camera issue but it may be very simple to fix.
 

   There is a possibility that the thin ribbon cable that runs from the sensor card in the front of the camera has become loose in the connection to the control card in the rear of the camera. I have had this happen to one of my ASI2600Mx cameras. With handling and vibration it seems that cable can loosen. The solution is to carefully remove the rear cover from the camera and gently reseat the clamps that hold the ribbon cable in the connector of the main circuit board. It is easy to do, just be gentle.

 

   When this happened to mine, the error was that the sensor temperature always reported 0 degree C. It might be possible to see other errors if the control card cannot communicate with the sensor card on all wires in the cable.

 

   I found a post somewhere here on CN that showed how to remove the back. A search should turn it up. Posts dealing with replacing the fan will also show what you need. Check and try that before sending the camera in for repair or replacing it.

 

 

John


  • Dean J., CharLakeAstro, tosjduenfs and 2 others like this

#6 syxbach

syxbach

    Viking 1

  • *****
  • Posts: 989
  • Joined: 16 Sep 2016
  • Loc: West Texas

Posted 04 December 2023 - 09:44 AM

Contact zwo customer service. They should have a service in the U.S. Or change to QHYlol.gif Moravian may be too expensive 



#7 v8vantage

v8vantage

    Sputnik

  • -----
  • topic starter
  • Posts: 31
  • Joined: 19 Feb 2021

Posted 05 December 2023 - 01:43 PM

"Any time I hear about intermittent issues like this, I automatically think communication issue. Try a different cable. If you are using a USB hub, try without the hub.

Tried that, no glory.

 

One thing that I did find was that the voltage sometimes droppet below 11.0V when all dew heaters kicked in.

 

Changed PSU and now I am well over 12.5V no matter.

 

/S



#8 Kevin_A

Kevin_A

    Surveyor 1

  • *****
  • Posts: 1,552
  • Joined: 22 Aug 2018
  • Loc: Belmont, Ontario Canada

Posted 05 December 2023 - 02:28 PM

If you are ok with taking 4 screws out and disconnecting the fan connector you could verify that all the connectors are properly seated inside. It is a easy check and nothing too delicate or tricky to do. The whole top and then when you disconnect the fan, the can then just slips off. I have had mine apart about 10 times testing out different fans and cleaning the bugs out of it. You could visually inspect the ribbon cable too as others have suggested.  


Edited by Kevin_A, 06 December 2023 - 09:40 AM.

  • CharLakeAstro and v8vantage like this

#9 v8vantage

v8vantage

    Sputnik

  • -----
  • topic starter
  • Posts: 31
  • Joined: 19 Feb 2021

Posted 06 December 2023 - 03:39 AM

If you are ok with taking 4 screws out and disconnecting the fan connector you could verify that all the connectors are properly seated inside.

Thanks Kevin, that is a great advice! Partly because I came to the same conclusion yesterday... grin.gif

 

The observatory is in Spain (I am in Sweden) and it gets a lot of sand from Sahara and the spiders really love living in my gear. Haven't upened up the camera for three years, so it is way overdue anyway.

 

Thanks!



#10 v8vantage

v8vantage

    Sputnik

  • -----
  • topic starter
  • Posts: 31
  • Joined: 19 Feb 2021

Posted 06 December 2023 - 03:41 AM

v8vantage,

 

   This does look like a camera issue but it may be very simple to fix.
 

   There is a possibility that the thin ribbon cable that runs from the sensor card in the front of the camera has become loose in the connection to the control card in the rear of the camera. I have had this happen to one of my ASI2600Mx cameras. With handling and vibration it seems that cable can loosen. The solution is to carefully remove the rear cover from the camera and gently reseat the clamps that hold the ribbon cable in the connector of the main circuit board. It is easy to do, just be gentle.

 

Thanks John!! Great tip! I'll have the techs in Spain have a look!
 



#11 Drothgeb

Drothgeb

    Surveyor 1

  • *****
  • Posts: 1,529
  • Joined: 12 Jan 2022
  • Loc: Maryland

Posted 06 December 2023 - 02:31 PM

I have a 294 that started giving me intermittent wacky patterns. I was pretty sure it was the usb connector, and was going to replace it. But I first tried using a dental pick to slightly lift the contacts in the connector hoping for a better connection. Problem went away.


Edited by Drothgeb, 06 December 2023 - 06:58 PM.

  • v8vantage likes this

#12 v8vantage

v8vantage

    Sputnik

  • -----
  • topic starter
  • Posts: 31
  • Joined: 19 Feb 2021

Posted 13 December 2023 - 04:45 PM

Well, there was a lot to clean inside of the camera after three years of operation, but my main concern is this dent in the ribbon band. Rather tricky to measure the resistance over the leads since one end is glued.

What do you think, should the individual leads survive such a dent?

 

IMG-20231213-WA0002b.jpg



#13 Kevin_A

Kevin_A

    Surveyor 1

  • *****
  • Posts: 1,552
  • Joined: 22 Aug 2018
  • Loc: Belmont, Ontario Canada

Posted 13 December 2023 - 07:58 PM

Well, there was a lot to clean inside of the camera after three years of operation, but my main concern is this dent in the ribbon band. Rather tricky to measure the resistance over the leads since one end is glued.

What do you think, should the individual leads survive such a dent?

 

attachicon.gif IMG-20231213-WA0002b.jpg

Maybe shine a small bright maglite thru it from behind and see if you can detect any anomalies when flattened out. That might show any fractures inside the ribbon. 


  • v8vantage likes this

#14 v8vantage

v8vantage

    Sputnik

  • -----
  • topic starter
  • Posts: 31
  • Joined: 19 Feb 2021

Posted 14 December 2023 - 07:02 AM

We (and I really mean my super hero technician Jose Fernando down in Spain) managed to measure all the leads of the ribbon band and they are all OK.

However, he also found a couple of spots of corrosion/sulphite on the back side of the PCB (see picture below) that now are cleaned away. And the camera seems to working as normal again, regardless of the level of cooling, binning and exposure time!!

IMG-20231214-WA0001.jpg

 

 

Me happy. wink.gif

 

 

Thanks everyone for your advice and support!


  • Tomvictor, jdupton, Jon Rista and 3 others like this

#15 flightlogic

flightlogic

    Vostok 1

  • *****
  • Posts: 155
  • Joined: 13 Oct 2022
  • Loc: Flagstaff, Arizona 7000 ft. MSL

Posted 15 December 2023 - 07:13 PM

In the avionics world that I work in, boards have a conformal coating. It seems like a sticky mess at times. But it prevents the corrosion we see on our hobby boards. With surface mount, things are surprisingly small. Glad someone with skills was onsite. Well worth what you pay in my opinion. Though leaving Sweden for Spain on occasion is not bad. I would just be booking and telling my wife “we gotta go honey…it’s the corrosion ya know”. Always works, right?
  • CharLakeAstro likes this

#16 CharLakeAstro

CharLakeAstro

    Vanguard

  • *****
  • Posts: 2,183
  • Joined: 12 Jan 2015

Posted 15 December 2023 - 07:33 PM

Very true. We conformal coat 90%+ of the circuit boards in the products we produce. Connectors are protected with high molecular weight connector gel.

Congrats "v8vantage" on resolving this issue.

 

In the avionics world that I work in, boards have a conformal coating. It seems like a sticky mess at times. But it prevents the corrosion we see on our hobby boards. With surface mount, things are surprisingly small. Glad someone with skills was onsite. Well worth what you pay in my opinion. Though leaving Sweden for Spain on occasion is not bad. I would just be booking and telling my wife “we gotta go honey…it’s the corrosion ya know”. Always works, right?




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics





Also tagged with one or more of these keywords: CMOS, Equipment



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics