Sky-Watcher 200P GOTO slewing round & round

[DobbieDave]

Hi,

Brought a skywatcher 200p GOTO recently & I am having issues getting the GOTO functionality to work at all.

I am able to successfully setup the 2 star alignment by centering the first star with controller & the scope will then slew round to the chosen second star with no issue.

The problems start after alignment.

When I choose an object to view after alignment the scope will slew round & round until I eventually give up and press esc on controller. 

I am not sure if this is a faulty mount or more likely something I'm doing wrong in the alignment process.

Any help would be appreciated.

Thanks

Dave

[Cornelius Varley]

Hello and welcome to SGL. The problem could also be due to an inadequate power supply. What are you using to power the mount ?

[DobbieDave]

2 hours ago, Cornelius Varley said:

Hello and welcome to SGL. The problem could also be due to an inadequate power supply. What are you using to power the mount ?

Hi, thanks for the reply.

I'm using a 'Celestron PowerTank 7Ah' for the power supply.

its a new powertank & fully charged etc.

 

 

 

[JOC]

It might be worth trying to slew without an eyepiece in or just using the small light plossls that may have come with the telescope.  My Goto mount is very sensitive to weight at each end of the telescope and I find having a large EP in place affects the ability of the scope to move.  

[DobbieDave]

2 minutes ago, JOC said:

It might be worth trying to slew without an eyepiece in or just using the small light plossls that may have come with the telescope.  My Goto mount is very sensitive to weight at each end of the telescope and I find having a large EP in place affects the ability of the scope to move.  

Hi JOC, thanks for the reply.

It's only got the small 20mm plossl in there at the moment.

Its able to slew perfectly during the alignment process but then decides to go all Kylie Minogue on me after that.

 

[Geoff Barnes]

Intriguing! If the scope is finding your second chosen star with no problem then your alignment must be okay.

I have had a few instances of my Dob slewing crazily, certainly low battery power has caused it once or twice.

On other occasions I found that simply redoing the alignment process rectified the problem.

We will get to the bottom of this, have no worries!  

[cletrac1922]

Dave

First of all welcome from Land Down Under

I use a car jump start pack for my EQ5pro mount

Seems you have everything set correctly respect to GPS location, date/time if able to do a 2 star alignment

Which DSO objects you trying to observe

Have you tried the moon, then venture from there

Attached pic shows my ED80 with jump start pack taken at a club solar day late last year

John

 

[Ledge1962]

Just to confirm it isn't a faulty encoder, go into the handset menu, Utility Func - Show Position, and move the mount up and down, then around and check if the Coordinates are updating. I had a similar issue with the scope aligning correctly, but as soon as I used Goto, it would just drop down and bottom out on the mount. It turned out the ALT Encoder was broken and we only found it because the Azimuth coordinates were updating, but the Altitude coordinates remained the same when raising and lowering the scope by hand.  If this is your problem, the Azimuth coordinates probably wont alter.

It may not be the issue, but worth ruling it out.

 

[Neil H]

Hi mate there another thing to try clear all data from hand set PAE etc , then just to try dont put the scope on the mount go through the alignment ( just tell the band it's lined up on the star ) then give it a target and see if it can find it , if it does try with telescope on it all is well that's great 

Now when you go out at night do the star alignment as normal , then give it a target it may be off so press escape then press and hold escape till it says centre ( what star you were looking for ) then centre it in the eyepiece then press enter you may have to do 3 stars but it will then get closer to spot on , doing this puts new data in the PAE , done this on mine and it's very close to the target star 

[DobbieDave]

2 hours ago, Geoff Barnes said:

Intriguing! If the scope is finding your second chosen star with no problem then your alignment must be okay.

I have had a few instances of my Dob slewing crazily, certainly low battery power has caused it once or twice.

On other occasions I found that simply redoing the alignment process rectified the problem.

We will get to the bottom of this, have no worries!  

Hi Geoff,

I stuck a voltmeter across the psu & it reads 12.5v.

So I am fairly sure the psu is good .

I like your optimism.

[DobbieDave]

2 hours ago, cletrac1922 said:

Dave

First of all welcome from Land Down Under

I use a car jump start pack for my EQ5pro mount

Seems you have everything set correctly respect to GPS location, date/time if able to do a 2 star alignment

Which DSO objects you trying to observe

Have you tried the moon, then venture from there

Attached pic shows my ED80 with jump start pack taken at a club solar day late last year

John

 

Hi John,

Thanks for the welcome.

I've tried going to several objects after alignment including the moon all with the same result.

I bet you get some clear skies down there?

I think my brother has one of those jump start packs I might be able to borrow & try.

 

[DobbieDave]

Thanks Ledge & Neil for some good advice.

I'll give those points a try & hopefully it solves it.

Getting a bit frustrating now. Spending all my time trying to get the GOTO to work rather than looking at anything much in the sky 😂

[JOC]

Its more expense, but not a hige amount more, but you can also get a mains power adapter for these telescopes.. I have one and it works well with an extension lead run from the house.   

[DaveL59]

used with an RCD of course...

[JOC]

2 minutes ago, DaveL59 said:

used with an RCD of course...

It's a specific lead - mains plug on one end, appropariate black square in the middle and the connector into the scope.  I'm not sure that a RCD is absolutely necessary - plug it in inside a house and just run the extension roll outside - I just use common sense and don't let it all get wet.

[Neil H]

you can play with the mounts day time just tell it it's lined up on your 2/3 star alignment then test on a target just to see if it stops 

[DobbieDave]

3 hours ago, Ledge1962 said:

Just to confirm it isn't a faulty encoder, go into the handset menu, Utility Func - Show Position, and move the mount up and down, then around and check if the Coordinates are updating. I had a similar issue with the scope aligning correctly, but as soon as I used Goto, it would just drop down and bottom out on the mount. It turned out the ALT Encoder was broken and we only found it because the Azimuth coordinates were updating, but the Altitude coordinates remained the same when raising and lowering the scope by hand.  If this is your problem, the Azimuth coordinates probably wont alter.

It may not be the issue, but worth ruling it out.

 

I tried this out.

The Alt & Azm are updating when I track the scope using the controller.

When I manually move the mount, only the Alt seems to track properly the Azm is very unresponsive.

[DobbieDave]

2 hours ago, Neil H said:

Hi mate there another thing to try clear all data from hand set PAE etc , then just to try dont put the scope on the mount go through the alignment ( just tell the band it's lined up on the star ) then give it a target and see if it can find it , if it does try with telescope on it all is well that's great 

Now when you go out at night do the star alignment as normal , then give it a target it may be off so press escape then press and hold escape till it says centre ( what star you were looking for ) then centre it in the eyepiece then press enter you may have to do 3 stars but it will then get closer to spot on , doing this puts new data in the PAE , done this on mine and it's very close to the target star 

I tried clearing the PAE & then running through alignment again but its still up to its old spinning tricks unfortunately.

I wonder if the firmware is corrupt on this particular mount.

I might try updating it to the latest firmware or try to force a reinstall if its on the latest.

Its on version 04 39 04 according to handset.

Need to get a cable first though.

Thanks to everyone for their tips & ideas so far.

[AstroFin]

Hi Dave,

Try another power cable. I used to have a bit similar issues with my Celestron CPC. Turned out it was all down to a faulty cable that was supplied with the telescope. 

Another thing worth asking, just to make sure, have you set your date in mm/dd/yyyy format?

 

[bottletopburly]

Check voltage output with a meter just to confirm correct voltage.

[DaveL59]

 

3 hours ago, Ledge1962 said:

Just to confirm it isn't a faulty encoder, go into the handset menu, Utility Func - Show Position, and move the mount up and down, then around and check if the Coordinates are updating. I had a similar issue with the scope aligning correctly, but as soon as I used Goto, it would just drop down and bottom out on the mount. It turned out the ALT Encoder was broken and we only found it because the Azimuth coordinates were updating, but the Altitude coordinates remained the same when raising and lowering the scope by hand.  If this is your problem, the Azimuth coordinates probably wont alter.

It may not be the issue, but worth ruling it out.

 

 

18 minutes ago, DobbieDave said:

I tried this out.

The Alt & Azm are updating when I track the scope using the controller.

When I manually move the mount, only the Alt seems to track properly the Azm is very unresponsive.

as ledge1962 above said, if the encoder isn't working properly when moving the scope manually, then maybe the encoder is the problem, in which case the GoTo isn't sure where the mount is pointing and just goes "wierd". You'll need to have a look at the motor/encoder to see what's up and if it can be fixed.

[DobbieDave]

22 minutes ago, AstroFin said:

Hi Dave,

Try another power cable. I used to have a bit similar issues with my Celestron CPC. Turned out it was all down to a faulty cable that was supplied with the telescope. 

Another thing worth asking, just to make sure, have you set your date in mm/dd/yyyy format?

 

I have another power cable that was supplier with the powertank. I'll give that a try thanks.

Yes setting the date American style.

[DobbieDave]

19 minutes ago, DaveL59 said:

 

 

as ledge1962 above said, if the encoder isn't working properly when moving the scope manually, then maybe the encoder is the problem, in which case the GoTo isn't sure where the mount is pointing and just goes "wierd". You'll need to have a look at the motor/encoder to see what's up and if it can be fixed.

Ok. I'll do some investigation on the motor/encoder.

It might have to go back as its only a few weeks old.

Thanks once again for all the help.

[Geoff Lister]

On 09/05/2020 at 13:39, DobbieDave said:

The Alt & Azm are updating when I track the scope using the controller.

When I manually move the mount, only the Alt seems to track properly the Azm is very unresponsive

A few years ago I had similar problems with my 250PX. The fault was a poorly seated ribbon cable connector on the underside of the azimuth control printed circuit board. It was very difficult to spot - I had to remove the board's mounting screws to see the underside. The ribbon cables passed through ferrite rings - probably a post-design modification to pass international EMC tests - and this extra detour made some of the cable runs very tight.

On 09/05/2020 at 14:22, DobbieDave said:

It might have to go back as its only a few weeks old.

Probably the wise option.

Geoff

[JOC]

Whilst it doesn't sound connected you might do worst than check your synscan settings with the Synscan Init 2.0 app. which will present you with all the necessary information in the correct format.  Including all the leading zeros that are sometimes necessary to enter for locations and the correct format, as mentioned above for date and time.