Why wont my skywatcher auto-tracking mount work? At All...

[caleb]

Hey, I have had my MAK80 for some time. But after going through several battery packs I decided to cut the cord and solder some clips on their. For use with a 12VDC transformer or a 12V rechargable battery.

Well it worked quite reliable for a while but not any more. Although it might go on for a few seconds, or the keypad will flash repeatatly.

The RJ45, or ethernet/phone style plug is slightly damaged, as the clip that 'clicks' it in broke off and I will have to hold it or put in a position so it will stay. Although holding the plug, I'm sure that all contacts are in contact. So I cannot say this is the problem.

So does anyone have any ideas?

[TrevorW]

Maybe it's because these scopes propably use a regulated power supply and unless the substituted power supply was regulated then it can cause problems.

I think

[Glenhuon]

If the supplied voltage falls too low this will happen. Had the same problem with mine when I let the 12v battery discharge too much. The mount will draw ~2 amps when slewing, if the power supply is not rated for this or more it will drop the voltage below the critical level (seems to be around 11v). Same with a faulty/low charge battery. Pretty sure there's a warning on Andrews site (?) re the Synta systems not being built to tolerate unregulated supplies.

Bill

[caleb]

Ok, thanks Bill. That seems to be a valid reason. I guess when you buy the 8!!! AA's for some $$$'s one or two of the batts may go before another:doh:So all up they don't last very long.

[caleb]

Well, I went out and bought some new batteries today. Chucked 'em in to find it still wont work:(

I tested the batts with my multimeter to find 13.5V, so is this too much?

As well as the 'middle' of the plug being the positive, I'm sure the middle is usualy the negative:shrug:

Just hope I can sort it out or my astronomy life is over:sadeyes:

[Omaroo]

NOOOOO!!!!!!!!!!!!!!!!!! Hardly ever! I hope that you didn't wire up your external supply with a negative centre and try it.... which might explain why it doesn't work now on batteries either.

[caleb]

Well, it was working although the hand control felt as though it was warm.

And another thing with wiring, I'm prety sure white is positive and black is negative, welly welly. Black is pos and white is neg in Skywacther lingo:rofl:



Actualy, come to think of it I ran the power into the battery pack with +/- (without batts) so I guess it was running through correctly.:shrug:


I wanna get a t-mount crank'en.:D

[Glenhuon]

Caleb, Synscan plug is centre pin Pos. In the battery case the Spring is Neg and the opposing pad Pos.
If the handpiece is getting warm, thats not a good sign. Methinks you need the services of an electronics doctor to give it a physical.
If your external supply is unregulated and poorly smoothed it could cause the warming and ultimately do permanent damage. Its the "ripple" in the DC that causes the problems. 13.8 is OK as its nominally 12v rated and will tolerate a couple of volts over. The idea is that when you start to pull extra power from it during slewing for instance the voltage doesn't drop below critical.

Bill

[caleb]

I'm not sure if an electronincs doc could do much, the problems are usualy invisble... Although I could be wrong, my bro is a sparky so I'll ask him.

I guess I can look around for a new hand controller.

[Robert9]

They should build these things with a series protective diode to prevent damage by reversed polarity input.
Robert

[caleb]

Thats what I would have thought, I'm prety sure the diodes heat up when they are stopping current.

[Robert9]

No, if they are not passing current then there will be no heat generated. P=IxIxR if I=0 then P=0. No power, no heat. If however there is a current by-pass diode across the power input socket which will carry the current if there is a reverse polarity connection, then there would be heat generated by that diode and any series resistive current-limiting component in the by-pass circuit. But if there is a reverse polarized protective diode which will just stop current flow, then why bother with the current by-pass.:screwy:
No, if things are getting hotter than normal, then it is my guess that something internal has blown. :(:(
Never rely on unconventional colour coding. Red positive and black negative - OK. Anything else, use a meter.
Robert

[caleb]

:mad2:

[Zaps]

Older DC "standard" was Red positive, Black negative. More recently, particularly with regard to photovoltaic systems, the Americans appear to have successfully changed the "standards" again, this time so that black is positive and white is negative.

No point bashing SW because you didn't bother to Google "polarity" +DC +colours...

[marki]

From pg 3 of the synscan manual.

The Synscan should be powered by 11 - 15V DC power supply (tip positive) capable of producing a continuous current of minimum 2 amps.

futher down ....

The power indicator will flash when the power is low. Continued use at this point may damage the Battery. The power indicator will flash rapidly when the power is extremely low. Continue to use the same battery may damage the SynScan system.

Mark

[Robert9]

Caleb, what sort of AA batteries did you buy? You should have alkaline rather than the standard cheapie. Only the alkaline will be able to deliver the current you need. Try Energiser or Duracel. Remember, the pimple cap is positive ( + ) and the plain end negative ( - ). The battery holder will be marked, but as a guide, the spring end is negative.
Looking at the manual I read that the hand controller receives its power via the RJ-45 cable. Are you sure the broken plug is making good contact. Your comment that sometimes things worked and sometimes didn't suggest you may have a faulty connection, and possibly that fault has become permanent rather than intermittent. With correctly applied power either from AA cells or an external battery (check out using a meter that the centre pin is positive before you plug it into the controller) try wiggling the broken connector. If you can get a response, tape the connector firmly in place then try the hand-controller buttons for any signs of activity.
If you can get the scope working, a computer shop should be able to help you with a straight through RJ-45 cable. (Someone else might like to comment on this, please feel free.)
Good luck,
Robert

[caleb]

I'm not sure if it's Synscan. I this its just some other Skywatcher thing.

I'm using Everedy batteries and my DVM is indicating the middle is positive with 13.5V

I also tested the contller pins with my multimeter but the two pins on each side didn't seem to register.

[Robert9]

Does the voltage change when you turn on the power switch?

[caleb]

Unfortuantly there is no switch, but I can plug it in and test from the battery pack. I can try that tomorow afternoon though, I'm not very happy with not getting a public holiday...

So I'll have to wait...

[Robert9]

OK Caleb. I'll check in again tomorrow night. If the voltage drops significantly it means that either the batteries are flat or are unable to provide the current. If the Eveready batteries you are using are just the plain red ones, then I don't think they can provide the power. You'll need to get alkaline batteries as I described previously (Energiser or Duracel.)
Sleep well.
Robert

[Robert9]

I didn't think there was a public holiday anyway.

[caleb]

For Anzac day, just VIC and QLD were getting it I heard.

And I'm using the black Evereadys.

[marki]

Caleb, if it is a synscan it will have two ports and a power port on the bottom of the controller. You can plug the power straight into the bottom of the hand controller and if it works you know something else is wrong. Most likely the cable from the mount as Robert suggests.

Mark

[Robert9]

Thanks for filling that in Mark. I've also downloaded the synscan manual and had the feeling that it should be possible to test the hand control separately. I just couldn't work out where the batteries were placed. Its important (need I say it) that the polarity is right!!! Caleb isn't sure whether it is a Synscan or not. My Celestron is clearly marked and I would expect other brands to flash their name too.
I just hate to see someone in trouble like this.
Robert

[marki]

Me too Robert. I actually have the synscan controller (ver 3) on my HEQ5 pro and its a funny thing. When I tried to upgrade the software as I do with my meades it did not work and the controller appeared to be dead, nothing, zilch. I took it back and got another one which did exactly the same thing when I tried to upgrade. I also thought I had reversed the polarity or my power pack had killed the controller. This time I re-booted and held the 8 key down and thankfully it came back to life but had no software on it. It turns out the software loader was bad and wiped all the code without replacing it. I dropped back and used an earlier version of the loader and hey presto, it all worked again. Never had a problem with the meade controllers which I update all the time.

Mark

[Robert9]

Sadly Mark we are in the hands of the so-called "experts". When things go wrong that aren't our fault, the heart-ache it creates I think can be worse than when we do something idiotic ourselves. At least we can blame someone. Either way, there is always a lot of chasing around to do. In that regard, I pity those that live away from the cities. But gee, I'd love to have the clear dark skies that those living out bush have. I guess you can't have it all ways.
I have been fortunate with my Celestron although I did suffer one failure which was in fact a faulty cable to the hand controller. Only took a week to get another one.
Let us now wait and see whether poor Caleb has had any luck. The AA batteries he has I don't think will power the motors but should be sufficient to power up the controller.
Just as an aside, I've just installed Kubuntu onto an old PC. (I'm running it now.) I want to check out the planetarium software, KStars. Could be good.
Robert

[caleb]

Ok, thanks once again guys. And sorry for the late reply...

I've tested to battery pack as it was plugged into the mount with the controller and it is the same as when it is not plugged in. The pack has also dropped to 12.7V from the original 13.5V

In reading your posts about Synscan I've come to hypothesise that I am not using synscan, no software updates here.

And I've used ordinary AA's before with no problems.

[Robert9]

OK Caleb, your absence had me a bit worried. Now I take it that the voltage you measure (12.7V) is there when the controller is both plugged in and switched on. Is there a rise in voltage as you switch the controller off? What I am trying to establish is whether the batteries are flat. If 12.7 volt is sustained when the controller is on, that should be enough for the controller to operate. If it is not operating then I feel sad.............
The only other concern I have is that the cable which you say has a broken plug, may not be making contact. If you can rule that out, then there is nothing left. Sorry.

Robert

[marki]

Caleb, can you take a picture of the controller and post it? Even if you just supply a link to your scope that would be helpful.

Mark

[Robert9]

I'm surprised the controller isn't clearly marked with the brand name. Most companies like to tell everyone of their existence in every way possible. Certainly Celestron have their name all over everything. But when all else fails, a picture can beat a 1000 words. - Good idea Mark.
Robert

[caleb]

Here you go -

http://www.skywatchertelescope.net/swtinc/product.php?class1=1&class2=109

Although my mount is black;)

[trent_julie]

I've been watching this thread for a little now, and whilst i don't claim to be an expert on any type of mount, I do have an electronics background. I would be heading straight for that cable, I've seen many high tech pieces of kit come undone because of a simple cable. Noting that this may not fix the problem immediately, it will definitely prevent this cable becoming a problem in the very near future.

I can't emphasise enough to replace that dodgy connection, if the connections touch yes, you may read voltage with a multimeter on the connection, but this may account for bugger all in reality due to a thing called impedance (its caught many a technician unstuck) that little tang is what assists in overcoming this thing called impedance

As for the hand controller, without schematics I can't tell, but for the hand controller to get hot I'm thinking the motor driver side of things (it doesnt make sense to me that driver FET's or tranies be in the hand controoler though), there maybe a Watt of energy or more there to get the hand controller warm, far more power than is required by a standard micro-controller circuit.

One thing that concerns me (without electronic diagrams once more) is that the unit may have had reverse polarity applied to it, Ive seen it many a time where these diodes are not included for the mere fact that the designed connections are not intended to be altered eg a mobile phone battery will only work when placed in the mobile correctly, so why does it need reverse polarity protection?

In my experience electronic components don't always display a visible defect, test equipment such as a Oscilloscope are required to chase out the faults due to data passing, pwm waveforms etc

(Thats my best effort at electronics in English without getting into long winded explanations)

Heres the good news,

A TV Dr is a very adaptable being, in lieu of having a telescope mount electronics specialist readily at hand, Even better if you know of someone with a fair bit of electronics experience.
It may only cost you a six pack for labor and parts (thats my charge if I get it things going again)

Good luck with the mount, Truly, I can imagine the amount of angst this is causing, I eagerly await the result of the fault

[Robert9]

Couldn't agree more trent_julie. From the picture Caleb, I would say the controller is not a Synscan. A Synscan clearly marks its brand name. BUT, the advert says it is a Synscan. Maybe its specially produced for Skywatcher????
Go for the cable Caleb. Is there a plug at both ends? If not you will definitely need a technician to solder a new one into the hand controller for you.
Robert

[marki]

Caleb, if that is your controller it is definately not a synscan so please disregard any posts I have made as they do not relate to your problem. A picture of the synscan is placed below. Good luck with it all.

Mark

[caleb]

marki - The imgae you posted is not what I have. Although it does look nice:)

I can get that clip replaced, although I realy think its fine if held correctly. It's only the part that holds it in place, it just broke off oneday. :mad2:

[marki]

Caleb, the crimpers and fittings are as cheap as chips. Go to DSE or Jcar and buy them. Repairing the cable is a 2 minute job. Just make sure you take note of the order of the coloured wires.

Mark

[caleb]

I was in JayC today aswell and I forgot the thing... I was doing something else there so the trip wasnt wasted though.

[trent_julie]

Whats the latest news?

[Robert9]

I fear the silence is ominous.

[caleb]

I think you've feared correctly... Omnius?

And still havn't got it working, although I havn't tried replacing the RJ45 yet so I still smell hope in the sky.

[Robert9]

Caleb, I think those following this thread are more anxious you.
We all await the outcome, hopefully a positive one for you.
May the force be with you!
Robert

[caleb]

Okay, geeze:lol: I'll try my best to take it down.

Don't worry, I havn't given up on astronomy. I was taking some photos the other night on my film SLR:thumbsup: I saw some meteorites out there, maybe they will show up on the film...

[Robert9]

Hope the meteorite photos come out. But come on, get that scope working!

[caleb]

Nooo, I took it to Jaycar yesterday. But cripmers were $20.. So I though I'd take it to my local telescope shop, but my dad thought I should try it again, so I did, and no action. So we left to the shop, and I sillily left the power plug in on my scope.. A few hours after this I thought I should pack my scope away, and I see the plug in and think, "Hmmm, Oh well" but when I put my fingers on their to pull it out that thing was bloody hot:mad2:

So unfortunatly I am lead to belive there are more things wrong, building up the $'s and frustration in my head..


And don't get me started on last night, I took my SLR out with 7 shots left and I bumped the shutter in the dark taking 6 X 10 sec exposures.:tasdevil:



Looks like there is some cloud rolling in as I type....

[caleb]

In the mean time


http://i811.photobucket.com/albums/zz40/air-ba/edF1000005.jpg

Well I posted the mount to Tasco Service on Wednesday, and it arrived today, Monday. With a new keypad and an invoice totaling $00.00:D
Gotta love 'em...

I'm back in the game gents.

[DavidU]

Excellent. Thats the suff !

[caleb]

Good stuff with the quick reply to mate.

[Robert9]

That's great news Caleb. Now for those clear skies!
Have fun and sleep well.
Robert

[caleb]

Well I took it outside last night with a very clear image of Jupiter. Could see the bands and moons:)