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Odd slewing issue with my CG5-ASGT

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#1 mikewayne3

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Posted 04 September 2012 - 10:04 AM

For over a year now I’ve been having an odd issue with my mount
Friday night while trying to image it was the worst it’s been so far
After doing a two star alignment I then did a drift alignment re-started my mount did a two star and then a 4 star calibration I started my imaging section.
While waiting for the North American nebula to clear the trees I started out on M27 then I did a precise goto it selected Sadr which at that time was on the same side of the Meridian but the mount went west all the way around till it got to Sadr. It tracked fine after that but I know it shouldn’t do that.
I was also having a different issue and replaced the input boards (I think it fixed that problem) but it didn’t fix this problem
Any ideas as to what’s going on here?
I have done a factory reset when this first started happening but it’s getting progressively worse
Mike

#2 RTLR 12

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Posted 04 September 2012 - 10:22 AM

Mike,

Have you upgraded the firmware?

Stan

#3 Eddgie

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Posted 04 September 2012 - 10:37 AM

I have had problems with both my CGE and my CG5-ASGT.

Every time I have had the problems, (It comes back), I have resolved it by using DeoxIT on the cable jacks and plugs.

These RJ type connectors were never intended for outdoor use, and I believe that in time, the contacts themselves develop either an oxide coating, or perhaps just get contaminiation.

A few years ago, someone on the forum said that the problem was the cables, so I replaced the cables, but in time, the problem recurred.

Cleaning everything with DeoxIT and plugging each plug 10 or 15 times to wipe the contact points always restores normal function.

At least for a while. Then I have to do it over again.

Again, these RJ connectors were not designed for outdoor use.

Oh, someone else mentioned that it was a ground problem with the shell of the RJ connectors on the CGE. I used a bonded grounding strap from the shell to the CGE, and it made no difference. The problem eventually came back.

Not saying it will fix your problem, but now, when I have any kind of intermittent problem start to develop, I just clean the contacts and it all goes away.

Good luck.

#4 SergeC

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Posted 04 September 2012 - 11:35 AM

I've only had my new-to-me CG5-ASGT out about a half dozen times, but on a couple of occasions it slewed in a way I thought was odd. Both happened under similar circumstances to what Mike describes: I'd done a 2+4 alignment followed by an all-star polar align. Re-doing the original alignment stars (Arcturus and Antares, west of meridian) was fine, with the OTA on the east side of the mount as it should be. But when I tried re-doing Sadr as a calibration star the mount kept the OTA on the east. At first I was tempted to just pull the power on it, afraid of a runaway slew and the OTA crashing into the tripod. But darned if it didn't slew to Sadr, putting it close to the crosshairs of my 9X60 finder. Needless to say, in that position it was a bit hard to crane my neck enough from my lying down position that I had to get into with the scope pointed the way it was. After that, everything seemed fine, using Altair and Enif as additional calibration stars the scope was positioned the way you'd expect for stars east of the meridian.

So, I'm thinking, does it have to do with the current RA limits or GoTo approach direction programmed into the HC? By the time I went to re-sync on Sadr after ASPA routine (and tweaking it with a short drift align), Sadr had moved much closer to the meridian, even though it was still to the east. Because of those limits, if an object is close to the meridian does the software point the OTA in anticipation of a flip?

#5 mikewayne3

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Posted 04 September 2012 - 12:27 PM

I updated the firmware about 3 years go
I've had this scope/mount for 7 years and love it even with the issues I'm having now

#6 RTLR 12

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Posted 04 September 2012 - 12:44 PM

Mike,

You need to update the HC and MC firmware.

Stan

#7 mikewayne3

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Posted 04 September 2012 - 01:33 PM

Thanks Stan I guess I should update them it has been a wile.
Eddie the contact problem is why I replaced the main input board as well as the Dec board. The contacts were looking ugly as well as out of alignment as of now I hadn’t given the cable’s themselves any thought, I guess I should clean them as well thanks for the suggestion
Mike

#8 mikewayne3

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Posted 04 September 2012 - 02:02 PM

One last question
Do I update each new update since my last update or just the latest?
Thanks again
Mike

#9 RTLR 12

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Posted 04 September 2012 - 02:16 PM

You just need to do the latest update Mike. Do you have the cables to do it?

Stan

#10 RobbW

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Posted 04 September 2012 - 02:19 PM

Mike,

You need to update the HC and MC firmware.

Stan


Stan, while I agree that updating firmware can often solve issues encountered with a newly-received CG5, I fail to see how it would magically correct a mount that had been performing perfectly fine for three years or so. If a mount has been working just fine for three years performing the same exact tasks the whole time, how would a new problem that arises while doing the same exact tasks be a result of firmware/coding (unless the firmware was somehow altered)? More likely it would be a mechanical/electrical issue, right?

Quite often, I see people recommend a firmware update when someone is having an issue with their mount. To me, that is akin to automatically recommending that a Windows XP user upgrade to Windows 7 even though Windows XP has been working perfectly fine for them all along. Sure, Windows 7 might offer more bells and whistles and allow them to use more complex applications, but it isn't going to fix their failing CPU fan or power supply!

#11 RTLR 12

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Posted 04 September 2012 - 02:46 PM

No Rob, it's not like updating from XP to 7. It's like updating XP to fix a known problem. This is done all the time. There are know issues with the firmware that Celestron seems to think is a corruption issue. The exact cause is not known, but the thought is power glitches. Updating the firmware not only adds more "Bells and whistles", but also installs fixes for many issues with the firmware. There are many things that can be done to diagnosis problems with these mounts, but some consumers are reluctant or uncomfortable doing them. The update suggestion is one diagnostic tool on the list of things to do. Do you suggest that people not try all the tools available? Or perhaps you can offer some constructive advise.

Stan

#12 mikewayne3

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Posted 04 September 2012 - 02:57 PM

yes I have the cable
Thanks

#13 RobbW

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Posted 04 September 2012 - 03:00 PM

No, no, Stan. I was not suggesting that people not try all tools available to fix a problem. My confusion was how the mount could suddenly develop a firmware issue if it had been working just fine for three years. If it's a firmware issue, I would think it would have reared its ugly head prior to this situation, especially if the owner isn't using their mount any differently now than they have ever used it.

#14 Stew57

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Posted 04 September 2012 - 03:04 PM

power spike from on off with the power switch is the current theory.

#15 RobbW

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Posted 04 September 2012 - 03:13 PM

Thanks, Mark. I could see that happening.

#16 mikewayne3

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Posted 04 September 2012 - 03:17 PM

I read hear in this forum about the switch so I just keep it on and plug and unplug it from power
I just replaced the main board which includes the switch so I don’t see how this is a power spike but thanks for the suggestion also I forgot to add after trying to image North American nebula I went for the pack man nebula and it did the same thing and I had to grab the Dec cable which was on it’s second rap around the head and give it some slack and then after it stopped slewing and started tracking I unplugged it untangled it and plugged it back in
I posted about this once before after it first happened and was told to reset factory settings and it did help but not for long
I’ll give updating the firmware and see what that does
Thanks for the suggestions
Mike

#17 mclewis1

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Posted 04 September 2012 - 05:26 PM

Mike,

All switches make some spikes when the contacts come together and temporarily bounce a bit, but there is usually some circuitry to reduce or eliminate it (capacitors and such). It looks like many switches that got used for a period of time by Celestron couldn't handle the amperage going though them and the contacts broke down and either welded shut (always on) or opened up (never on). Leaving the switch on and using the power cable to turn the mount on and off seems to work just fine for some folks ... and it certainly doesn't hurt anything.

What looks like is happening with the Celestron hand controller is some very rare changes to the non volatile ram (where the settings are stored). So far no one has found anything definitive for the problem and since it happens so in frequently it's very had to troubleshoot.

Like Stan mentioned, there are little changes in the past firmware updates that may help out a bit.

#18 RobbW

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Posted 04 September 2012 - 09:29 PM

I also leave my power switch in the "On" position and just plug/unplug the the power cord as needed. Actually, I have a power switch on the power cord on the end that plugs into the 12V outlet on my power supply. I also have power switches on each outlet on my power supply and a main switch for the whole unit. I may have gone a little overboard with switches!

#19 Peter D.

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Posted 04 September 2012 - 10:00 PM

Speaking as an experienced engineer and tech, switches are flaky even when new, and they get worse with use and age. Another problem area is the power recepticle on the CG5: the center pin is split to give some spring to the contacts, but after only a few dozen uses it doesn't spring back far enough to make a good contact. One quick solution is to split it back apart with a thin penknife or jeweler's screwdriver. For the switch, run it on-off a few dozen times with the power disconnected, leave it on, and don't touch it after that. Of course a better solution would be to replace (or bypass) both the switch and connector, but that's a bit more work with a soldering iron. Cheap power connections and switches are a never-ending problem in the commercial world; that's why reliable military stuff is so outrageously expensive.

#20 mikewayne3

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Posted 05 September 2012 - 01:13 AM

thanks for all the suggestions
I just updated the HC and MC firmware and I'll keep an eye on the power
Mike

#21 mikewayne3

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Posted 05 September 2012 - 09:54 AM

BTW Pete I know what your saying
I assemble equipment for the Military and it is amazing how much Mil speck connectors cost
Mike

#22 mikewayne3

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Posted 05 September 2012 - 09:55 AM

:brick::

#23 EFT

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Posted 05 September 2012 - 10:40 AM

Odd behavior in these mounts (and many others) often come down to either a power supply issue or a firmware corruption issue (and the two may even be related). These issues can happen at any time, from new out of the box to many years old. That's why factory resets and firmware updates or reinstallations are often recommended. It's a cheap and easy thing to try when things start acting wierd. From there you go to looking at your power cable and supply and from there you get into the tough (more expensive) problems. It's amazing how often a factory reset or a firmware upgrade or reinstallation fixes things right up.

#24 mikewayne3

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Posted 10 September 2012 - 11:05 PM

I have updated firmware on the hand control and replaced the jack on my power supply but now I'm thinking I have the wrong power supply
I'm using a 12V 1.5A power supply, is it possable it's not putting out enough amps?
what is the power requirments for this mount?
suggestions?



#25 EFT

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Posted 10 September 2012 - 11:15 PM

I have updated firmware on the hand control and replaced the jack on my power supply but now I'm thinking I have the wrong power supply
I'm using a 12V 1.5A power supply, is it possable it's not putting out enough amps?
what is the power requirments for this mount?
suggestions?


You definitely want more than 1.5 amps. I prefer to go with a minimum of 3 amps and 5 is even better. The old Celestron 1.5 amp power source was simply not enough for much of anything.






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