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CG5 ASGT problem- Round 2

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#1 WOBentley

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Posted 02 February 2011 - 09:44 PM

I posted my problem with this mount a few months ago. Living in the PacNW we don't get to go out much this time of year so last night was my next chance. On attempting to align...the computer/hand control (which oddly does not ask for lat/long input) asks for time information, asks which alignment (one star/two star etc.) I want to do, has me pick a star (from a seemingly very limited list, Betelgeuse and Rigel were not included but in good position for me to see from my limited visibility lot). I selected Sirius...it started to slew, then after a few seconds of slow slewing, the computer wanted me to re-enter all the initial information, like it had reset, However, the telescope after a short pause (even though it was still asking for initial information again) continued to slew, paused again and then slewed to fairly close to Sirius. Of course the computer was not asking me to center the star, it was still asking for re-entry of the initial information. When I posted this last time I was told that intermittent power issues were common and I should slightly spread the power connector (which I did). There was absoultely NO flashing of the red light, power seemed continuous but this still happened. Last time I do not remember it continuing to slew...but as I didn't know the mount I probably just reentered the information too quickly for the "pause" to have ended.
Any other ideas? Faulty computer? It is most frustrating indeed! We don't get that many clear nights. Any suggestions for next steps (just buy an AP900 :) )
For full disclosure the scope is an Antares 1529 (6" f6.5) achromat that was well balanced (and the previous owner used a CG5 without problem with this scope).
Thanks for any help...I suppose it may be time to send it back to Celestron/Dealer???

#2 Trev

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Posted 02 February 2011 - 09:59 PM

Well if you know for sure that it isn't a power problem then the next step would be to check for broken wires, cracked solder, faulty connectors or a HC that may be faulty from factory.

#3 RTLR 12

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Posted 02 February 2011 - 11:02 PM

Simply spreading the connector does not eliminate all power problems. Before you dive into the electronics you need to do some other test. What you are using to power the mount and the power cable it's self need to be checked and eliminated first. All of my Celestron power cables (3) that came with my mounts have failed for one reason or another. I had a problem exactly as you describe that turn out to be a faulty Celestron power cable. Upon replacing the faulty cable with one of better quality the problem was fixed.

Stan

#4 Mary B

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Posted 02 February 2011 - 11:23 PM

The stock power cable is a joke. The inner conductors are very fine and breakage would be easy. The symptoms would be intermittent like you were having. Low voltage could also be a problem. What were you using for a power supply?

#5 WOBentley

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Posted 02 February 2011 - 11:39 PM

Thanks for your help, here are the answers to the questions...
Power supply is a 12 volt deep cycle marine battery that is essentially new and fully charged.
I have only used one power cable...where would one find a better quality one (as I assume the answer is not celestron). I will need a good one anyway when I do get this sorted out. How would one look for broken wires (VOM?)
Cracked solder may be beyond my ability to fix...but I am happy to look if anyone has a suggestion as to exactly where to look. Also how would i be able to tell if the handset is "faulty from the factory"? I am an Eq. noobie having used a Meade LX 90 for the last several years. I expected a learning curve, but this seems like more than I should have to learn!
Thanks again
Dave

#6 Fred1

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Posted 02 February 2011 - 11:57 PM

On attempting to align...the computer/hand control (which oddly does not ask for lat/long input) asks for time information, asks which alignment (one star/two star etc.)

...I suppose it may be time to send it back to Celestron/Dealer???


Just hit "Undo" when you start alignment to get to the coordinates input.

If you can provide a link to your older thread we might be able to avoid some duplication of effort.

It does sound like a power supply issue. Here's a cable source: http://scopestuff.net/ss_cc14.htm

Otherwise, it might be time to return it to Celestron.

#7 RTLR 12

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Posted 03 February 2011 - 12:40 AM

I use these on all my mounts...8'long, coiled, fused, has an ON/OFF switch with LED power indicator, and has a 90° connector on the mount end.

Stan

http://www.radioshac...$10.00 - $14.99

#8 jimb1001

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Posted 03 February 2011 - 12:59 AM

Thanks for your help, here are the answers to the questions...
Power supply is a 12 volt deep cycle marine battery that is essentially new and fully charged.
I have only used one power cable...where would one find a better quality one (as I assume the answer is not celestron). I will need a good one anyway when I do get this sorted out. How would one look for broken wires (VOM?)
Cracked solder may be beyond my ability to fix...but I am happy to look if anyone has a suggestion as to exactly where to look. Also how would i be able to tell if the handset is "faulty from the factory"? I am an Eq. noobie having used a Meade LX 90 for the last several years. I expected a learning curve, but this seems like more than I should have to learn!
Thanks again
Dave


I was experiencing similar problems. I bought a new cable from Radio Schack, one with its own switch on the adapter, at the suggestion of several on this forum. I spread the pins inside the Celestron end and put the Celestron cable in a box.
No problems since. I never remove the cable from the scope or the power supply or use the switch on the mount, just flip the switch on the adapter. The switch on the mount seems to be a weak link, too.

#9 Jim-M

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Posted 03 February 2011 - 01:48 AM

Dave,
I also had a bad Celestron power cable. Recommend that you replace it with a heavier duty model, such as the Radio Shack unit mentioned above or similar. If you use Radio Shack, the "Type M" end adapter fits a CG-5. It is 5.5mm OD, 2.1mm ID.

If you want to check the cable and have an ohmmeter that can measure less than one ohm, you can measure center pin to center pin resistance, and outer contact to outer contact resistance. Assume that you know how to do this with the cable disconnected from any power and the mount. Each leg should be less than 1 ohm, preferably closer to one-half ohm. If it is much more than one ohm in one or both legs, the voltage drop during high speed slews will cause highly erratic mount behavior.

My original cable did not appear to have broken wires or intermittent contact. Just relatively high resistance of 5 ohms in each leg.

Good luck.

#10 rmollise

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Posted 03 February 2011 - 06:21 AM

The stock power cable is a joke. The inner conductors are very fine and breakage would be easy. The symptoms would be intermittent like you were having. Low voltage could also be a problem. What were you using for a power supply?


That's true. But the usual problem is using a battery that's not fully charged or an AC adapter not able to put out enough clean current.

#11 WOBentley

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Posted 03 February 2011 - 10:12 AM

Gentlemen
Thanks for the input. Thanks also for the "undo" tip, I did not think of that!
I will be off to Radio Shack as soon as they are open (only 7am here!) I like the idea of the on/off switch on the cable and I can likely get one today...we may have clear enough skies that I can try it out tonight.
As far as the old thread...I will try to find it, but essentially it was all about finding electrical faults...
I can use a VOM (I even own some VTVM's) and have a Ham Radio license...but it has been more than 30 years since I have picked up a soldering iron for any real work so I would be uncomfortable doing that, would prefer to send it back to the factory if I have to go that far.
Dave

#12 mclewis1

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Posted 03 February 2011 - 11:09 AM

Dave,

That re initialize that you saw is definitely power related. The problem may not be the power source, it could be the cable (good to get the RS version) or could be some connection problem .. but a momentary loss of power (no matter how brief) is what will cause the HC to start the initialize routine again. One thing to keep an eye on is the power switch itself. These have been notorious for going bad on a CG-5, when then do they usually don't work any more but they can break down internally and cause an intermittent re set like you saw. The full fix is to replace the switch (there have been a few threads on this and the replacement switch has been documented) but the easier way to mitigate it is to cycle the switch on/off a number of time (with no power) to "exercise" it a bit, maybe check it with a VOM (you don't want to see any resistance across the switch when it's on) and then to leave it in the on state and use the power plug to turn the mount on or off.

With a good cable and the switch checked out you should be confident that you don't have a power related problem. I would use the VOM on a voltage setting and keep an eye on your battery power level ... you can learn a lot about it's current state and how effective your charging is just by monitoring the voltage level when the mount is turn on (a light load). You should see voltages up in the 13.5 or 13.8 range for a fully charged battery ... going down to maybe just under 12v when it's under 50% used.

You got the direction to use the Undo to back into the location information. I would do a reset to Factory Settings just to clear out any strange inputs and start over on all the Time/location data entry ... just to be sure.

As for the limited selection of the alignment stars remember that the mount will only choose stars on one side of the meridian or the other, so effectively there are two lists. You can tell which list is in use by the little E or W in the upper RH part of the display when selecting the stars from the list. To get to the other list simply press the Menu button. This is called E/W filtering and it's in the manual.

The Advanced Series manual is for HC v 2 or 3.
The v4 Addendum is for HC v4.10-4.12
Use the CGEM manual for HC v4.15-4.16
Use the CGEPro manual for HC 4.18 and above

It's best to choose alignment stars from one side of the meridian and the calibration stars from the other side ... but if you have limited sky access you can choose them all from one side, your gotos just won't be as good as they could be (but will likely be just fine for your use).

#13 jrsmith

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Posted 03 February 2011 - 11:16 AM

hi! my nightmare began when i got my mount and excitedly used it indoors to "play with it". every time i would allign my fake star allignment it would star the procedure over again. after dimantaling the controller -and so many things i will not go into!,i bought a new controller for $150. of course excitedly powered up same problem!!-bottom line power cord was not getting good contact at insertion on mount!!!! new cord- no problem DOH!!! power 12v. imperitive-and undo button to put you lat and long!! i know this is a sad inexperienced story!!

#14 Fred1

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Posted 03 February 2011 - 01:48 PM

... One thing to keep an eye on is the power switch itself. These have been notorious for going bad on a CG-5, when then do they usually don't work any more but they can break down internally and cause an intermittent re set like you saw. The full fix is to replace the switch (there have been a few threads on this and the replacement switch has been documented) but the easier way to mitigate it is to cycle the switch on/off a number of time (with no power) to "exercise" it a bit, maybe check it with a VOM (you don't want to see any resistance across the switch when it's on) and then to leave it in the on state and use the power plug to turn the mount on or off. ....


I'm pretty sure this is the power switch if you have a mind to replace it, but not without caution, if the mount is still under warranty:
CG5 Power Switch

#15 WOBentley

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Posted 03 February 2011 - 03:22 PM

Looks like the warranty is for two years and I have had it less than a year so it is still under warranty...will try power cord, but likely will not try switch swap!

#16 mclewis1

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Posted 03 February 2011 - 04:19 PM

I'd only consider replacing the switch if you found a specific problem. I mentioned it only because most folks usually over look it when troubleshooting power problems and there have been quite a few cases of failures.

#17 cavefrog

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Posted 04 February 2011 - 12:33 AM

yup! the switch was bad in mine when I received it used. I just used an external switch untill other problems showed up a couple years later. while I had it apart, I shorted the switch permanently on by soldering a wire across the terminals.

just for grins and giggles , I would try the power supply that was made for the mount. you can do this inside , and do not need to waste your precious dark time.

Theo

#18 nemo129

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Posted 04 February 2011 - 08:38 AM

I selected Sirius...it started to slew, then after a few seconds of slow slewing, the computer wanted me to re-enter all the initial information, like it had reset, However, the telescope after a short pause (even though it was still asking for initial information again) continued to slew, paused again and then slewed to fairly close to Sirius.

Any suggestions for next steps (just buy an AP900 )

When this exact same behavior happened to me on my CGEM, it turned out to be an intermittent contact to the HC. It seems there was an issue with the crimp at the RJ style connector end. Fortunately I have a CG-5 and I swapped in that HC and voila the issue went away (I had been thinking power issue before I figured it out). It took Celestron 3 weeks to replace the HC. Not that bad, but then again I had a fill-in! I am not saying this is you issue, but when I read your post it was a Déjà vu moment for me. I wish you luck in working out the issue whatever it turns out to be. The definition of frustration for me is getting good viewing weather and having it spoiled by equipment issues!

The AP900 is a next step for me. I know there is no such thing as an issue free mount, it is just that some mounts seem to have fewer issues than others. Of course you do pay for that! ;)

#19 WOBentley

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Posted 04 February 2011 - 12:50 PM

Thanks...
Of course since I live in the PacNW the predictions for the clear night did not work out...looks like Thursday is the next possibility. I had not thought of trying inside...I could even do that in the evening with the scope roughly (OK very roughly) polar aligned...just to see if it slews without resetting. I assume if I turn off without "centering" it won't cause problem? If that part works I can then wait for the next clear night. If not I can try looking at the HC issues mentioned above...
I have Radio Shack power cable so I will try that tonight...I also do have the AC adapter so I could try that too, but only if I can't get the RS cable to work as I will likely not be using this at home as much as I will be remotely...
Again, all the help is MUCH appreciated....

#20 mclewis1

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Posted 04 February 2011 - 01:29 PM

Dave,

Running "fake" alignments indoors is a great way to exercise the mount and check out problems, it's warmer, brighter and there are usually more refreshments at hand.

#21 WOBentley

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Posted 04 February 2011 - 03:30 PM

Dave,

Running "fake" alignments indoors is a great way to exercise the mount and check out problems, it's warmer, brighter and there are usually more refreshments at hand.

:waytogo: :foreheadslap:
Not really sure why I never thought of that!

#22 Pedestal

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Posted 04 February 2011 - 09:47 PM

Check for cold solder joints.

#23 FoxTrot

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Posted 05 February 2011 - 07:01 PM

If it still plays up after investigating cable issues, I reckon if you took it to your local astro shop (hopefully you have one) a side by side comparison with a new mount/HC should diagnose the problem... Fox

#24 WOBentley

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Posted 07 February 2011 - 01:24 AM

Sadly our one local astro shop closed about 8 months ago....






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