Blown single drive hand controller - help

[Astro78]

Hello any and all electronics gurus

A while back I accidentally pumped my hand controller 12v instead of the required 6v. This seemed to have killed the thing quite effectively.

Thought i'd open it up and have a look (with my low electronics skill 'n all), replaced the diodes without any luck...

Just wondering if there's something obvious i should replace? Perhaps the ICH thingy is toast?

No idea.

Any help would be great :thumbsup:

[Gama]

You need to follow the tracks that the 12V travelled on.
But i hate to say it, but if it doesnt have a fuse on the board and at least a overvoltage detector, your in trouble.
It may be best to let some one with a little electronic knowledge to have a squiz at it.

Theo

[Astro78]

Well certainly no fuse and believe no over voltage detector present.

Think you may be right Theo, just had a bit time on my hands.

Thanks for your reply

[Barrykgerdes]

Hi Astro78

Firstly what is a single drive hand controller. I can't identify it by that name. The most common failure with over voltage is blown capacitors especially tantalum. IC's often survive over voltage as long as they don't draw too much current that cooks them.

If you had a photo of the board it may help. A circuit diagram would be even better.

Without knowing the part it is impossible to diagnose. Have you access to a multimeter. Check for shorts on the 5/6 volt supply line. If it shows a short look for diodes and capacitors and if supect unsolder one leg and see if the short goes.

Barry

[DeanoNZL]

Hi Astro78, is it similar to this? (see pic)
If so, I have this one that is no use to me.
Only problem is the distance to send, unless you know of anyone crossing the ditch soon.
Free to you. (In the spirit of IIS)

[Astro78]

Hi Deano,
Mate that is a mighty fine offer, thank you very very much :thumbsup: It is the same mine but the dual drive which will work a treat. Can i wire you postage or perhaps even post you a box with return stamps if easier? I don't know anyone crossing the Tasman this year.



Hi Barry, thank you for your reply, but considering today's burns from the soldering iron and Deano's offer - I might see if he can post 1st :thumbsup:

Man i love the astro community - you guys rock!

[luka]

You most likely killed the IC. See here (http://telescope.marford.me.uk/Projects/PICcontroller.htm)for someone else applying 12V to the dual-axis controller and frying it (and hence building a new one).

Also I remember reading how someone managed to fry the same controller using 6V from a power adapter instead of batteries - apparently the current limitation in the circuit is done by the batteries and the power adapter was providing much more current... can't find the link though.

[Barrykgerdes]

Hi Astro

Where are you located. I am in Sydney. If you can bring the controller around I will look at it for you. I have some repair facilities as I do PCB repairs to LX200 main boards.

Barry

[Astro78]

PM sent to the fine gentleman Barry and Adrian

Thanks for you reply and link too luka

If my original controller gets a second life, it will be offered here free.

[Gama]

The reason the plugpak burnt out the circuit is because they are not regulated, so the voltage would have easily been 12V or a little more.
The plugpaks are rated at the stated voltage when the current draw is matched. So if the circuit isnt drawing that much current then the voltage will be higher.

Theo

[Glenhuon]

I fried mine a while back by accidentally hooking 12v to it, finally traced it to the IC being cooked. The device is programmed to run the controller and while you can get the IC, the program isn't available. Only way out is a replacement controller unfortunately.

Bill