Oooohhhh and in a pop and puff of smoke I killed it

[h0ughy]

My new second hand redcat51 dad 3 focuser just died. I must have made some stupid mistake connecting it up and powering up. To be honest I am gutted. It certainly doesn't smell nice. And I don't actually think that the inside should look like that :eyepop::sadeyes:
And here I was preparing for spsp

[peter_4059]

Looks like an arduino nano with a stepper motor controller breakout board. Looks like the damage is to the stepper motor breakout board which should be quite easy to replace. The whole thing looks home made. Who built it?

[peter_4059]

Found the source code if the Nano is fried...

https://github.com/DeepSkyDad/AF3

[h0ughy]

I am out of my depth Peter, I did send an email to the guy asking for a new board but it will depend on what he thinks it's done

[Kirthgersen]

Oh no David. That’s terrible.

[peter_4059]

On a lot of those stepper motor control circuits there is a capacitor across the incoming power supply. The bit that looks cooked in the photo looks a lot like a capacitor. It might ne as simple as removing and replacing that component. The manufacturer should be able to tell you the rating of that part.

[Bart]

Yep, my guess is you've popped a cap in its ***.


Someone that is good with electronics should be able to assist.

[h0ughy]

It's an deepskydad focus motor https://deepskydad.com/autofocuser/redcat/assembly/dovetail#dovetail-110-assembly-instructions

[Peter Ward]

Just dab a little toilet paper on it mate....it will be fine after that. 😁

[h0ughy]

No that's too dear, just a little question Mr Ward how did you connect up your qhy? Can you enlighten me with your holey scroll of wisdom and a photo or two

[spiezzy]

hi David i am sure Pavle will help you out he is pretty descent fella
hope all goes well
cheers pete

[h0ughy]

In contact with him now, very expensive mistake given the value of our dollar

[Peter Ward]

I don't use an auto-focuser...well... not with my SpaceCat

...but a WO Copper-T (EOS) adapter and Cyclops Optics Blade C adapter gives me the exact spacing I need to
drop a QHY or Canon DSLR behind my Red/SpaceCat51.

Works very well :thumbsup: and nothing to go "pop" ;)

[h0ughy]

Thanks I will have to work out how to connect my asi294mc Pro?

[ChrisV]

You can run into trouble if connecting/disconnecting the motor from the driver while powered up. But all that you can do with your unit is plug in power and USB. So this sounds weird to me. You could just get a 100uF/50V electrolytic cap locally and try and see if that does the job.

Other than that, I'd be worried that the motor and/or the stepper driver might also be fried. To check the stepper, unplug it (with no power on) and meaure across red-blue then green-black leads. Should be a few ohms, if not then its blown.

If its the nano or the driver (it'll be a FYSTEC something or other) then looks like you are out of luck as they appear to be soldered directly to the board and hard to replace.

[h0ughy]

Thanks Chris for that information.

I decided to get a new board from pavle, so should hopefully have it by April

[PhilTas]

Houghy,

The blown component is an electrolytic capacitor. They are polarised, with positive and negative leads.
Most times I have seen these blown like this is due to a reverse polarity connection.
I would try cutting away the capacitor, identifying if able the positive and negative leads, as well as the value and voltage rating.

A new replacement cap will be easily sourced.

If you need any assistance pm me. I am an electronics technician by trade.

cheers Phil

[sunslayr]

If you do decide to give fixing it a go, it might be a good idea to clean the board as well, electrolytic caps tend to cause corrosion if they aren't tended too when they spill their guts everywhere. I've heard vinegar is good for neutralizing it but that might depend on whether its an acidic or a basic solution. I'd just use isopropyl alcohol or contact cleaner to be safe.

[h0ughy]

I will probably get it fixed after I get the new board arrives and I can take pictures of the offending bit.

[h0ughy]

I will leave that to the expert

[PaulSthcoast]

Isopropyl alcohol,

good luck finding that with current panic buying.

It is one of two ingredients for home made hand sanitiser.

Paul.

[JA]

Sorry to hear of your woes. It looks as though it may be as simple as failure of the electrolytic capacitor as others have stated. This can be caused by over voltage, reverse polarity, or long term aging of the capacitor resulting in increased internal resistance ( esr) which in turn results in overheating and failure. And when they blow as you know they smell terrible.

I would simply get the capacitor replaced, if it's possible to carefully read the capacitor rating on the plastic sleeve of the capacitor, BUT BEFORE DOING THAT, OR EVEN REPLACING THE WHOLE BOARD, I would make sure that the correct power supply is being used, and even if the correct power supply is being used I would test its output to ensure it meets the specification of the focuser, for both correct DC voltage output and the absence of other potential unwanted output such as AC spikes or excessive AC content.

Best
JA

[h0ughy]

The lead I bought from jaycar has gone back and they tested it. Rather than go ballistic I asked that they pull another random from the shelf and test that. I must have got the one made after a Friday liquid lunch as it was the wrong polarity.. I now have a new tested cable. But I will now test it in the future.

[raymo]

Wouldn't you have a case against Jaycar, if the faulty cable blew the
capacitor? I imagine that they in turn would chase the manufacturer.
raymo

[h0ughy]

Well the discussion was not without that point, however the lead had adjustable tips to wit could have been tampered with. I am just grateful for the mother board coming. The discussion was going nowhere with jaycar.

[g__day]

Looks just like a blown power capacitor - fingers crossed that is simple, quick and cheap to fix.

[h0ughy]

When I eventually get the replacement board I will take some photos of that and then get someone to fix the old one as a spare

[peter_4059]

Are you planning on blowing it up again? :question: Come to think of it, this wouldn't be your first time so probably a good move :rofl::rofl::rofl:

[h0ughy]

That's cruel and no, 😉 trying to think positive

[h0ughy]

OK given the fact that the replacement board is stuck somewhere overseas I asked Pavle if he could give me the information about the capacitor.

The capacitor is 100 uF / 50V. (Edit )it cost 95cents

So now to find somewhere to get it done.

[Camelopardalis]

Centre positive ;)

[DavidU]

If you get stuck I will fix it. Electronics tech here.

[h0ughy]

Pm sent David, thank you