Reverse polarised my EQ6 mount

[Carl M]

Hi all,

Having recently come back from University and finally having the time to take up Astronomy again, tonight I made a very naive and stupid mistake. The power cable connecting to the mount snagged while using the goto and removed the tip from the cable. I then very stupidly connected the tip to the cable again and completely forgot the fact that the orientation of the tip matters. I then reconnected it to the mount and turned it on. Although I had a 50% of being successful, the dreaded sound of something not very good bellowed across the garden (and it wasn't just the mount).

I've opened the mount up and had a look at the motherboard and the only damage that I can see is that one of the capacitors looks like it's blown. I'm not very familiar with electronics though and it could very well be more than that, but how can I check for damage if it's not visually damaged?

Apologies for dodgy iPhone picture but the lower black capacitor on the left looks damaged compared to the one above it.

Would it be a job of just replacing that capacitor and it should be working again?

Thanks in advance,

Carl

 

[MARS1960]

I only managed a year of my  HND and that was  23 years ago but from what little i remember what you have done is caused a dielectric breakdown so the capacitor has just expelled all it's charge, it should not have caused damage to any other components but i could well be wrong.

[r3i]

Sorry to hear about that.  You're not the first and probably won't be the last person who's experienced this.  Hopefully a knowledgeable person will stop by to assist with repairs but if the worst comes to the worst you can purchase a replacement board from here:  http://www.opticstar.com/Run/Astronomy/Astro-Accessories-Mounts-Skywatcher.asp?p=0_10_5_2_0_60

 

[Carl M]

15 hours ago, MARS1960 said:

I only managed a year of my  HND and that was  23 years ago but from what little i remember what you have done is caused a dielectric breakdown so the capacitor has just expelled all it's charge, it should not have caused damage to any other components but i could well be wrong.

It certainly sounded like a discharge, like air being released from something. Makes sense since the damaged capacitor is bulged at the top and has a crack going across it. I didn't notice any burning smell after it happened or when I opened the mount up so fingers crossed nothing is fried. 

5 hours ago, r3i said:

Sorry to hear about that.  You're not the first and probably won't be the last person who's experienced this.  Hopefully a knowledgeable person will stop by to assist with repairs but if the worst comes to the worst you can purchase a replacement board from here:  http://www.opticstar.com/Run/Astronomy/Astro-Accessories-Mounts-Skywatcher.asp?p=0_10_5_2_0_60

 

Thanks Mike, I suspect the link will come in handy if replacing the capacitor isn't successful.

I'm going to order a replacement capacitor, if the specs of the replacement capacitor are the same as the original I assume the brand doesn't matter? I'm toying with the idea of buying a soldering iron and doing the repair myself although I've never soldered before, after being quoted £40 just to put in the new capacitor it's looking more likely! 

[wimvb]

The lower capacitor is definitely toast. Replacing it can be tricky, since the circuit board is multilayered and has very fine copper strips.

Capacitors are cheap, so if you want to diy, buy more at the same time. Also buy a few of the other one (top). It is very likely damaged as well.

Worst case, some other components are fried as well, in which case you're better off getting a new board. Consider this an opportunity to learn how to solder.

If you've never soldered before, test first on some old defunct electronic device you may have lying around.

Good luck