Electronic stupid Mistake

[sgalvin]

Hi ALL,

This is my 1st post on the forum, i hope to get some help to get over what has happened.

I am using a Furuno FCV-663, using it as an echo sounder only, the problem started one day when we connected the 12VDC Wrongly, usually there's fuse that prevents voltage from passing through to the unit.
Unfortunately we edited the fuse , instead of a simple fuse, we connected several thin copper wires to allow the voltage to pass through.

THIS Very time voltage was connect in the wrong side, the pos. to the neg, and the neg to the pos.

the whole unit Couldnt start up. I opened the whole unit and use a digital mulitmeter to check the power supply, the supply of 12VDC to the main board was 'shorted'.

I therefore tested the capacitor ( Brand stated nitsuka 2.2-100 ) and there wasnt any Ohms reading on it, it was also shorted.


Anyone has faced such bad mistakes before and how should i resolve it ?

Advise needed.

Thank you
Alvin

 

[Wreck Rider]

Re: Electronic stupid Mistake

Alvin

I never did this with a sounder but its a fairly common mistake with guitar effects pedals. Some manufacturers install a diode across the main power in that has no effect when good polarity power is applied, but it shorts reverse polarity power so it protects the main board. Short time error of power applied with wrong polarity has no permanent effect, just protects the electronics. Longer time of power applied wrong results in permanent damage to that diode. It becomes a short. So it still protects the electronics but will stop the thing from working when you apply power the right way.

First thing is find if there is a diode on the board that has heat damage around it. If there is one, cut it with pliers or cutters and check if the unit works now with power connected the right way. If it doesn't work, cut out that main capacitor you checked with the multimeter, then connect power the right way and see if the unit works now.

Let me know if this helps.

Andrew

P.S. where are you boating?

 

[sgalvin]

Re: Electronic stupid Mistake

Andrew,

Cool , seems to be a plan, I hope to get it going again.

P.S : I Boat in Singapore, Nothin too much to look around =) Just do some relax fishing.


Alvin