Need advice before buying Celestron CG5 AS-GT.
Posted 06 February 2014 - 09:06 PM
"an error code that says the hand controller has lost communication with one of the drives on the mount. I think it is the declination axis, because the mount slews non-stop in declination when I try to do a polar alignment."
My question is will this mount be a money pit? I am tech savvy and I have a fair grasp of electronics but are these mounts generally serviceable by an individual or am I going to end up having to send it in to Celestron at my expense?
Realistically speaking I don't have a budget for a new mount but if I don't go with this mount I'll probably save up money for another year and get the Celestron Advanced VX mount.
What should I do?
Thanks so much,
Posted 06 February 2014 - 09:25 PM
Posted 06 February 2014 - 10:02 PM
1) The AVX is a superior mount.
2) Even if you can fix the problem of the CG-5, you have no guarantee that that's the *only* problem with that CG-5. You could get into a chain of problems, and be spending money to fix every one.
3) And if you fix everything, you have a used mount that, realistically, will not live forever (I'm not down on CG-5's at all--I own one, love it, it's my only mount, and it's been working fine for 11 years. But I wouldn't spend more than $325 or so to buy my mount today--and mine *works*).
Posted 06 February 2014 - 10:03 PM
The MC board ruins $107 and a new motor runs $132.
Posted 06 February 2014 - 10:19 PM
Posted 06 February 2014 - 10:40 PM
Swap the 2 connectors and re-test the mount. If the DEC motor continues to run non stop, then you have a bad MC board, but if the RA motor now runs on and on, then you have a bad motor encoder.
If he buys it, that's how to diagnose it - but I believe you have the symptoms backwards. If the dec motor continues to run away when connected to the RA output the dec motor is bad. If the RA motor runs away when connected to the dec output then the MC is bad.
Posted 06 February 2014 - 10:47 PM
Posted 06 February 2014 - 10:48 PM
You're right. I was in a hurry when typing and misspoke. Thanks for the correction.
Posted 06 February 2014 - 10:55 PM
At $300 a good working CG5 is a good deal, at $175 it would be amazing.
So if, and only if, the prospect of it being a bit of a work-to-be-done project is fine with you then it sounds like a reasonable deal to me! If the prospect of work/gamble give you an even slight hesitation though the AVX is indeed a slightly better mount and includes no "if" factor.
The one thing that would give me pause is if it is an early CG5 with the version 3.x handset instead of a version 4.x handset. The 4.x models can have their firmware updated, the 3.x ones can not, the 4.x ones have the All Star Polar Alignment feature, the 3.x ones do not.
Posted 06 February 2014 - 11:06 PM
Posted 06 February 2014 - 11:09 PM
I have a CG-5 ASGT and its really a good mount, Kasey
I've owned a couple. They are a very good value. Had to replace a motor in one, and had to bypass the power switch on the other. Such failures don't appear to be all that common; I wouldn't be afraid to buy another one.
Posted 07 February 2014 - 10:56 AM
That's usually caused by a bad encoder, which is part of the motor assembly. That wasn't too bad in the past (the motor assy used to sell for $29) but I think the current price is more like $150. If it isn't the encoder it's probably the motor control board which costs at least that much. Or you could hit the lottery and it's just a bad connection between the board and the motor and you can fix it for free. I believe that's the least common situation.
OR...it could simply be a bad declination cable. However, unless you are willing to deal with it, don't buy a mount with known problems. OTOH, while the mounts can have encoder and other problems, most of the problems are pretty simple and relate to poor and dirty connections and poor power.
Posted 07 February 2014 - 10:57 AM
Also check the handset if its Nextstar+, I believe the ASGT should come with that model, Kasey
Only, perhaps, if it were one of the last ones sold.
Posted 07 February 2014 - 11:06 AM
OR...it could simply be a bad declination cable. )
That would count as a bad connection between the MC and motor as mentioned above. I haven't seen one, though. Just a bad motor.
Posted 07 February 2014 - 03:02 PM
Posted 07 February 2014 - 03:44 PM
PS - If you are in the US, couldn't you just buy a new encoder from US Digital, I thought about it but paying delivery and import duty and tax it wasn't worth it for me
I stripped my old motor down so I can give you the shaft dimensions if you need them
Posted 07 February 2014 - 04:03 PM
That is an earlier series 3.XX non programmable hand controller...
Posted 07 February 2014 - 04:19 PM
This sounds like a REAL fixer upper, getting more and more concerned...
If he has already replaced those parts why wouldn't he just finish refurbing the rest and sell it for a higher price?
Posted 07 February 2014 - 04:32 PM
Posted 07 February 2014 - 05:04 PM
Posted 07 February 2014 - 05:19 PM
Posted 07 February 2014 - 05:24 PM