Skywatcher SupaTrak mount fix

[Michele Scotti]

Hi All, a newbie here. I recently bought a 127mm Mak Skywatcher telescope+mount that I could not test before the purchase. It turned out that while the scope is in good optical condition the mount electronics is dead.

It's quite an inexpensive mount so I'd like to try and fix it because it's quite an handy one and because I don't like to throw things away. Also I like to learn and fixing the electronics is a challenge I'm ready to take (??!). While doing that I plan to tune all the mechanical stuff too. 

So to be clear the symptom is simply that with the handpad attached there is no sign of life at power on.

I disassembled both handpad and mainboard in search of some obvious fried components - I also used a thermal camera to check for some hot spots but was all cold dead.

I attach here  some pics to recognize scope and electronics. Sure I have a multimeter to make some checks as well as access to an oscilloscope.

Any hint, suggestion?

 

[Carbon Brush]

I assume the cables from the 12V power socket & handset socket to the PCB are existent, but not in any of the photos.

Component U1. Top right corner of main PCB.

This is a voltage regulator. Rated 5V 0.5A output.

The leftmost pin may well be a dry soldered joint. Certainly the solder has not flowed well.

Reflow this joint then check for 12V in and 5V out of this device on the pins. The 0V common is the tab.

See how it goes. David.

[jambouk]

If you can’t fit it, put a wanted add on astro buy sell UK for a new mount arm, you’d probably get one for £40.

[Cosmic Geoff]

Sounds like a power issue. With a multimeter, you should be able to find out how far power is getting into the assembly.

If no good, astroboot.co.uk or astroboot.eu  regularly has subassemblies for this mount at modest prices.

[Michele Scotti]

Hi All, thanks a lot for the support. I've start going though the suggested checklist and while trying to power on the scope I realized something odd.....mismatch.

Then the attention drifted to the wrap of the battery bank...uhmmm.

So yes it was a power supply issue! The most silly one actually - I reckon the previous owner had some dodgy modification since the jack wasn't wired properly too. 

It all works now! IMG_0208.MOV

However thanks for the support - this leaves me a couple of lessons. Firstly sometimes an issue is less severe than expected and a rigorous check of the basics it's key. Secondly I got reassurance of the power of the community and the warm feeling that guys like you, with your suggestions, made me feel not alone - and I was really ready to check all diodes, caps and resistors!

 

[Cornelius Varley]

That would probably do it. Meade tend to use a 2.5mm dia power plug whereas Skywatcher and Celestron use 2.1mm.