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

Nexstar 11 GPS tracks great for about 10 mins then..

  • Please log in to reply
68 replies to this topic

#1 NickInSac

NickInSac

    Explorer 1

  • *****
  • topic starter
  • Posts: 69
  • Joined: 14 Aug 2019
  • Loc: Sacramento, CA

Posted 12 February 2020 - 12:28 AM

...The Alt changes!!!

 

 

What I have:

Nexstar 11 GPS HC 1.2 and MC 1.0.  Yah... I know.  But this is the OLD one and is not flash programmable through the connector.  I don't want/need to upgrade if it can hold onto it's Altitude.

 

 

At Orion when it was working great... Azm showed 180 03, Alt showed 46 03.

I noticed when it lost tracking,  the alt changed to 17 degrees. Azm did not change. 

 

 

Questions and my thoughts of what it could be.

  1. Seems to be and altitude sensor problem... 
  2. Seems to be a battery (internal) problem where it won't keep it's tracking, I checked tracking it is set for sidereal.
  3. Seems to be a power problem, tonight I was using a motorcycle battery tight connections all around.  At the beginning it was showing 12.58 volts, after my session it was showing 12.48 volts.  I also have a 2 amp power and a 5 amp regulated power.  These AC power units gave similar problems, but I wasn't keeping notes too well.

Something else I noticed is the level sensor is off by about 17 degrees.

After I did an alignment, I tell it to calibrate level.

It does the up and down and stays up about 17 degrees...wait for the controller, then a code flashes on the screen, twice I got 54833.  Another time, I forgot the number but it was different.

 

Another anomaly is the hand controller seems to lose connectivity in the default side connector when I twist and pull it a little.  After I did this, the direction buttons stopped.  I did it some more and it seemed to have rebooted and or needed alignment.  If I use the Aux 1 connector and twist and pull it, it doesn't seem to lose connectivity for split second.



#2 NickInSac

NickInSac

    Explorer 1

  • *****
  • topic starter
  • Posts: 69
  • Joined: 14 Aug 2019
  • Loc: Sacramento, CA

Posted 12 February 2020 - 12:32 AM

My experience tonight

I level the tripod.  I do a two star alignment and it gets pretty darn close to Venus.  Sweet!..  I am taking pictures at prime with my canon T3i and in the middle of it (around 10 minutes).  It just starts to slew to the right (West?) about 20 degrees.  The controller was mounted in the side default connector.  

 

The controller shows Venus...  Umm.. I tell it to go to Venus again, it slews left (East?) gets it left and right correct but it continues to go up ... up and up!!  I stop it since my camera is on the bottom about to hit.

 

Then I notice the controller has issues with the side default connection.

 

Plug it into Aux 1.  This doens't seem to have any issues.

 

Turn it off and on again.

I do an Auto Align.  I tells me to place the tube about horizontal and North.  I find Polaris, mostly line it up and get the tube level with a level on it.  Hit enter.  It wants to go to a star (I forgot the star).  I point it to it, then it wants to go to Rigel and it almost nails it.  Hit align and tell it to go Venus.  BAM.  Almost right on it. I tell it to go Messier 42 (Orion's Nebula).  Bam almost dead on.  I get some pics.. for about 5-10 minutes. I hear the motor change and now it's tracking is off.   :(

 

I tell it go back to Orion and it goes up and up and UP! 

Redo...  ugh.

 

Maybe this is a hand controller connection issue?

But why does it only lose ALT and consequently tracking?



#3 jrcrilly

jrcrilly

    Refractor wienie no more

  • *****
  • Administrators
  • Posts: 35,585
  • Joined: 30 Apr 2003
  • Loc: NE Ohio

Posted 12 February 2020 - 12:37 AM

The level sensor is a simple ball in a track. The ball can get stuck if the mount is not used for an extended time. It can be cleared by declutching the alt axis and swinging the tube through level several times. You'll hear the ball rolling when it is cleared.



#4 NickInSac

NickInSac

    Explorer 1

  • *****
  • topic starter
  • Posts: 69
  • Joined: 14 Aug 2019
  • Loc: Sacramento, CA

Posted 12 February 2020 - 09:40 AM

Thanks for the reply. I hear the click. The level does seem to work, but off by a considerable amount. I thought it was adjustable. But from what I can tell after taking off the two side plastic panels neither the rod (bolt with a long spacer on it that is not in a slot) on the arm rotation nor the sensor (didn’t take the metal framing part off to actually see the sensor on the other side) can be moved.
I thought it could be adjusted.

#5 NickInSac

NickInSac

    Explorer 1

  • *****
  • topic starter
  • Posts: 69
  • Joined: 14 Aug 2019
  • Loc: Sacramento, CA

Posted 12 February 2020 - 12:48 PM

I did try reseating the circuit chips in the controller a while back. Maybe I need to do it again.

 

https://www.nexstars...NEnds/HCFix.htm



#6 NickInSac

NickInSac

    Explorer 1

  • *****
  • topic starter
  • Posts: 69
  • Joined: 14 Aug 2019
  • Loc: Sacramento, CA

Posted 12 February 2020 - 08:20 PM

I can’t get it to fail in the house. I’m beginning to think the alt clutch is slipping with the extra weight of the DSLR. Could also be the cold. Or combination.

I’m setting up a DIY sliding weight bar using 80-20 bars.

🤔

#7 NickInSac

NickInSac

    Explorer 1

  • *****
  • topic starter
  • Posts: 69
  • Joined: 14 Aug 2019
  • Loc: Sacramento, CA

Posted 12 February 2020 - 08:28 PM

Aaaahhh. I spoke too soon.

I had it go to Venus. It was a little low. I had it move up a little and then told it to go back to Orion M042. According to the hand controller it’s thinks it’s at 126 10 azm and alt is 33 10. Except the scope is about 190 degrees azimuth off.

It’s got to be a bad connection in the hand controller. Right??

#8 NickInSac

NickInSac

    Explorer 1

  • *****
  • topic starter
  • Posts: 69
  • Joined: 14 Aug 2019
  • Loc: Sacramento, CA

Posted 12 February 2020 - 09:58 PM

Trying again. Right after alignment. Go to works pretty good to Orion Nebula. Azm 150 27 and alt 41 10 showing in the hand controller. I go to Venus. Alt is a little off. I correct it. And go up a little. I then tell it to go to Orion Nebula again. It goes and is pretty close.

Suddenly the motors stop humming. I check azm in the hand controller. It’s 152 27 but it thinks alt is at 00 00. 🥴

For some reason it is losing either Azm or Alt.

I’m guessing something is wrong with the hand controller or power.

Tonight I’m using a regulated 5 amp 12 laptop power supply. Ugh

#9 NickInSac

NickInSac

    Explorer 1

  • *****
  • topic starter
  • Posts: 69
  • Joined: 14 Aug 2019
  • Loc: Sacramento, CA

Posted 12 February 2020 - 10:14 PM

I noticed the tracking mode was turned to OFF. Ugh.

Firmware?
Chip?
Loss of power for a sec?

#10 NickInSac

NickInSac

    Explorer 1

  • *****
  • topic starter
  • Posts: 69
  • Joined: 14 Aug 2019
  • Loc: Sacramento, CA

Posted 12 February 2020 - 11:26 PM

I reset the chips in the hand controller. Meaning, I removed the big chip, I was able to move the smaller chips a little bit as I don’t have a chip puller.
I put a moderate amount of pressure and felt the little chip (32 pin) a little bit.
I was able to reinstall the larger 68 pin (I think) chip.

It booted and then I did a factory reset.
Reset all my settings.

I played with it for just short of an hour with no more glitches.

Maybe it is solved. I’ll try it again tomorrow night.

#11 Michael_Swanson

Michael_Swanson

    Author of The NexStar Users Guide

  • *****
  • Vendors
  • Posts: 2,546
  • Joined: 23 Apr 2003

Posted 12 February 2020 - 11:28 PM

Hi Nick,

 

There is just a lot of possible causes for the errors you are seeing.  It could be the hand control (least likely), it could be internal cabling related to the ALT motor, it could be the large "serial board" under the top panel of the circular base, it could be the motor control board, it could be the encoder on the alt motor, and I could be leaving something out.

 

A couple of things first.  The alt sensor is a switch in the GPS mount and it's sole purpose is to allow the system to move to a somewhat level starting point.  It has no affect whatsoever on operation after a successful alignment.  Second, most laptop power supplies provide 18 or 19 volts - you don't want anything higher than 14 volts for your scope.

 

Back to attempting to fix this.  I would start by opening up all the plastic covers and reseating every cable connection - just slide the plastic connectors off and on a couple of times to wipe off any minor corrosion.  BE CAREFUL that you do not misalign any pins on that connectors or you can definitely damage the electronics (permanently).  Open the back of the hand control and reseat the connector for the coiled cable (though it might actually be soldered to the board on that version).  Conduct your next tests with the hand control plugged into either of the AUX jacks on the top of the base.

 

Let us know how that goes.

 

Best regards,
Mike Swanson
https://www.NexStarSite.com



#12 Michael_Swanson

Michael_Swanson

    Author of The NexStar Users Guide

  • *****
  • Vendors
  • Posts: 2,546
  • Joined: 23 Apr 2003

Posted 12 February 2020 - 11:28 PM

I hope you just proved me wrong and the hand control was the only issue :-)


  • NickInSac likes this

#13 NickInSac

NickInSac

    Explorer 1

  • *****
  • topic starter
  • Posts: 69
  • Joined: 14 Aug 2019
  • Loc: Sacramento, CA

Posted 12 February 2020 - 11:57 PM

Thanks for the replies.

It almost seemed as if the hand controller connection was bad.
The normal side connection is loose. But I couldn’t replicate that in the aux1 port. 
but it did seem to reset either Alt or Azimuth. I’m not sure what does this tho now. 

I don’t know if resetting the chips or resetting the defaults solved it. Or if it is solved.

Curious if you’ve heard of people losing tracking by going back and forth between planets and DSOs. As I recall this changes from lunar to Sidereal. Right????

I’m done for the night. I’m going to leave it plugged in for a while to see if I can get the time clock to keep time.
is It normal for it to only keep last programmed date and time?
 


Edited by NickInSac, 13 February 2020 - 12:02 AM.


#14 NickInSac

NickInSac

    Explorer 1

  • *****
  • topic starter
  • Posts: 69
  • Joined: 14 Aug 2019
  • Loc: Sacramento, CA

Posted 13 February 2020 - 12:16 AM

Well bummer. It was tracking Orion and I left it on.

I press Get Alt-Az now it says Az at 01 10 degrees and counting and Alt was at 00 00. It wasn’t touched. It SEEMS like it kept tracking Orion. But if I told it to go to Orion it wanted to go 158 and 44. Which of course is WAY OFF.

UGH

#15 Michael_Swanson

Michael_Swanson

    Author of The NexStar Users Guide

  • *****
  • Vendors
  • Posts: 2,546
  • Joined: 23 Apr 2003

Posted 13 February 2020 - 12:18 AM

No, the system does not change tracking rate from sidereal automatically.  After a successful alignment, it stays on sidereal all night unless you change it in the menu.

 

Your experiences are not normal and in rare instances when I've heard of such erratic behavior, it was an electronic issues like the ones I was talking about above.  I was skeptical of the hand control being the issue as it seemed like you were saying the problem is always on just the alt axis.  If both axes seem affected then the HC could be the cause.  And, if both axes are affected it could be your power source or the slip ring surrounding the azimuth axis could have some corrosion on it (all power to the electronics passes through that slip ring).

 

The GPS module does have a real-time clock in it and the hand control references that for time.  If the GPS module is having issues it will have the date/time from the time you used it.  Since your scope is now nearly 20 years old, I'm sure the battery on the GPS board is bad.  On this page of my website:

https://www.nexstars...OddsEndsGPS.htm

see the article "Replacing the Battery on the GPS Board".

 

Best regards,
Mike Swanson
https://www.NexStarSite.com



#16 NickInSac

NickInSac

    Explorer 1

  • *****
  • topic starter
  • Posts: 69
  • Joined: 14 Aug 2019
  • Loc: Sacramento, CA

Posted 13 February 2020 - 08:38 AM

Ok. I will try reseating all the cable connectors.
Thanks again for your reply.

If all power goes through the Azm ring. That seems a more likely culprit. I will check this and look for corrosion and clean too.

The GPS is disabled. Since I have the old MC and HC versions.
A while back the GPS battery was dead. I left it plugged in for a few days and the battery came back to 2.6x IIRC still below the 3 volts tho.

I will go back to using my MC battery for a power supply.

Thanks again.

#17 NickInSac

NickInSac

    Explorer 1

  • *****
  • topic starter
  • Posts: 69
  • Joined: 14 Aug 2019
  • Loc: Sacramento, CA

Posted 13 February 2020 - 11:47 PM

The power ring looks excellent. The power connectors were a little loose, not much tho. I reseated the connectors in the base.

I didn’t look at the power connector near the main power board on/in the cover. I’ll look at that next.

It did it again. Both Azm and Alt went to 00 00. :(
But it continued to do sidereal. The numbers went up slowly.


Could it be a chip over heating. I was thinking of getting some programmable chips and flashing them to actually replace the existing ones.

Other suggestions?

It’s on my motorcycle battery tonight with soldered connections and the plug to the base is not and solid. The battery is holding for an hour at 12.51 volts.

Nick

#18 NickInSac

NickInSac

    Explorer 1

  • *****
  • topic starter
  • Posts: 69
  • Joined: 14 Aug 2019
  • Loc: Sacramento, CA

Posted 14 February 2020 - 12:11 AM

I’m leaning towards the MC board. I’m not sure where this is.

It seems like the MC board is losing power and therefore resets to 00 00 on both axis. IIRC there is one MC board.

So, if the MC board loses power the rest of the system thinks it’s still tracking and therefore sends its instructions to MC board... yes???

#19 Michael_Swanson

Michael_Swanson

    Author of The NexStar Users Guide

  • *****
  • Vendors
  • Posts: 2,546
  • Joined: 23 Apr 2003

Posted 14 February 2020 - 12:49 AM

I’m leaning towards the MC board. I’m not sure where this is.

It seems like the MC board is losing power and therefore resets to 00 00 on both axis. IIRC there is one MC board.

So, if the MC board loses power the rest of the system thinks it’s still tracking and therefore sends its instructions to MC board... yes???

 

There are electronics in both fork arms so take those covers off and reseat connectors there as well.  The MC board is in the fork arm with the vertical handle.  On this page of my website, you will find links to a couple of article Celestron published explaining how to get to the MC board:

https://www.nexstars.../GPSMCBoard.htm

 

You are correct that if the MC board resets it will send 0/0 coordinates to the hand control and the hand control will still keep going as if nothing happened.  

 

Best regards,
Mike Swanson
https://www.NexStarSite.com


  • NickInSac likes this

#20 NickInSac

NickInSac

    Explorer 1

  • *****
  • topic starter
  • Posts: 69
  • Joined: 14 Aug 2019
  • Loc: Sacramento, CA

Posted 14 February 2020 - 01:03 AM

Thanks for the reply. I appreciate it.

I reseated the MC board connectors. I tried wiggling the power cords to see if it would blank out. I tried to check the cords themselves with my volt/ohm meter.

Nothing seemed to phase the power connectors.
Not sure what else now.
I’ll test it again with out tracking going. I don’t think I’ve tried that yet.
I’m starting to lean to the controller again. But, I just can’t quite wrap my head around the logic.

I have a Nexstar plus from my 4Se. IIRC it’s at 4.6. Not sure tho. Can I downgrade that firmware to work with the MC 1.0?

#21 Michael_Swanson

Michael_Swanson

    Author of The NexStar Users Guide

  • *****
  • Vendors
  • Posts: 2,546
  • Joined: 23 Apr 2003

Posted 14 February 2020 - 01:25 AM

Doubtful you would be able to get the NexStar+ HC to work with MC 1.0. All info I have indicates the MC must be at 4.06 to work with the NexStar+ HC.  You might try NexRemote on a Windows PC connected via the PC Port on the top of the base.  Try the older NexStar GPS 1.6 version in NexRemote, it might work with MC 1.0.  

 

Info on NexRemote here:

https://www.nexstars...l/NexRemote.htm

 

Info on the cable for the PC Port here:

https://www.nexstars...ammingCable.htm

 

Best regards,
Mike Swanson
https://www.NexStarSite.com



#22 NickInSac

NickInSac

    Explorer 1

  • *****
  • topic starter
  • Posts: 69
  • Joined: 14 Aug 2019
  • Loc: Sacramento, CA

Posted 14 February 2020 - 09:16 AM

Thanks for the info. You and I have been here before.
:)

I did run the scope last night without alignment or tracking and it did not change Alt or Azm back to 00 00.

I’ve found I can just about run any version of the nextremote directly plugged into the bottom of my HC and run the scope.

I’m curious if the HC or MC or mother board controls the tracking ?

I’m also now curious to see if my nexremote will track and then if it will get an alt Azm reset to 00 after 20 minutes or so. I will try this. i think with this test, if the nexremote works well and no tracking issues, my hand control is the problem.

What do you think?
Thanks

Edited by NickInSac, 14 February 2020 - 09:17 AM.


#23 NickInSac

NickInSac

    Explorer 1

  • *****
  • topic starter
  • Posts: 69
  • Joined: 14 Aug 2019
  • Loc: Sacramento, CA

Posted 14 February 2020 - 12:12 PM

Hello,

I can control the scope with the NexRemote on my PC to the hand controller and to the scope.  I get the same results after about 10 minutes of tracking it goes back to Azm and DEC of 00 00.  This shows up in the NexRemote as well.

 

Sooooo.... MC is toast?

 

I might try and flash it to 1.6 and see if I can get anywhere...  IDK  frown.gif

 

I will try and get the NexRemote to connect to the PC port and see the results.  I need a USB to RJ45 adapter... hmm.


Edited by NickInSac, 14 February 2020 - 12:23 PM.


#24 mclewis1

mclewis1

    Thread Killer

  • *****
  • Posts: 19,548
  • Joined: 25 Feb 2006
  • Loc: New Brunswick, Canada

Posted 14 February 2020 - 03:20 PM

...   I need a USB to RJ45 adapter... hmm.

No, any old similar looking cable is likely to be a problem. You need the specifically wired Celestron serial cable (#93922) plus a USB to RS232 serial adapter (which you already have). There have been USB serial adapters with an RJ45 connector on the market that did not work in the Celestron PC Port.

 

Some folks did also splice the correctly wired serial cable onto a commercial USB to serial adapter so they had one solid cable and I think there was an example of one of these sold commercially but because of there being other similar setups that don't work you'd need to be really careful. 

 

IMHO it would be best to find a Celestron #93922 serial cable or make one from the info on Mike's website and use it with your existing USB-serial adapter.



#25 NickInSac

NickInSac

    Explorer 1

  • *****
  • topic starter
  • Posts: 69
  • Joined: 14 Aug 2019
  • Loc: Sacramento, CA

Posted 14 February 2020 - 04:18 PM

I’m trying to make a serial to RJ45 It’s pretty hard to find a DB9 cable locally.


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






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics