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        Question Genius CP circuitboard caught on fire, what happened???

#1 Hajile Nov 17, 2012 07:15 AM

Genius CP circuitboard caught on fire, what happened???
 
My tail was starting to split, it was so loose i can twist it 90 degrees without a problem, and i think that was why the tail was starting to wag so much.

I ordered a new tail set from eHirobo but it won't arrive for another two weeks so i went over to the local hobby shop (yes, the same guys i bought the 450parts that didn't fit) and bought a tail motor from them. The thing about it tho is that the tail blade was split in two so they gave me another tail blade. I did wonder what kind of force it had been subjected to have a tail blade break.

So i changed the tail section, plugged in the batteries, and powered it up. The heli started spinning uncontrollably, it seems the tail motor wasn't spinning. So powered it down while i tried to figure out what was going on.

Then all of a sudden thick smoke started coming out of the canopy and it was lighting up. The thing actually caught fire!

http://www.rcgroups.com/forums/showa...6&d=1353157428

The misshapen chip with the white top between the RX chip and the connectors was actually glowing very brightly.

Can anybody explain what happened? What was the chip that burned up? Can a faulty tail motor cause that?

#2 Hajile Nov 17, 2012 07:30 AM

1 Attachment(s)
I unplugged the tail motor and checked the wires.

http://www.rcgroups.com/forums/showa...9&d=1353158859

What the??? Did i strip the wires while i was putting it in? Can a loose plastic frame (it slid in rather easily) strip wires and cause them to short?

I've put the original tail boom in and out of its socket multiple times and that never happened!

#3 zadaw Nov 17, 2012 07:39 AM

I am almost certain that your tail motor wires shorted and that caused a blown tail fet. The wires were most likely damaged as you took them out of your original tail boom. It would have been a good idea to replace he wires with thicker 26 or 28 SWG wire then. In any case, you should check with a mutlimeter for any potential signs of shortage before you put the new tail in.

The problem with the blown tail fet is probably not that difficult to fix. Walkera will probably fix it for free provided that you go through your vendor. Otherwise, there are people around who knows how to fix it.

The issue with blown tail fets has happened to me many times with the mCPX, Genius CP and Mini CP. I am absolutely sick of this problem and have stopped flying 100 class CPs altogether.

#4 Hajile Nov 17, 2012 07:49 AM

No, they weren't taken out. The reason i got a tail set was so i wouldn't have to mess with any wiring. I just took it out of the package and plugged it in. The wires, tailboom, and motor all came together.

#5 zadaw Nov 17, 2012 07:54 AM

If the tail motor was already damaged, that could also cause a short. I have also had shorts before after flying in the rain. I wonder why was tail blade damaged in the first place? Has that tail been used before?

#6 Hajile Nov 17, 2012 07:58 AM

Nope, the package is sealed with a broken tail blade inside. How the hell did they store this thing??? I don't suppose i can demand the hobby shop to replace the heli?

#7 zadaw Nov 17, 2012 08:20 AM

I suspect they will try to shift blame onto your board. But at least you should ask them help you to fix the board or get a new one at cost.

#8 Air Vaca Nov 17, 2012 12:03 PM

that looks, to me, like a dead short. Probably in the connector of the new tail section. But, that is part pure speculation. The brushes in the tail motor could short, too...if certain things, that can, happen. A pinched tail motor wire can do it , also.

#9 Hajile Nov 17, 2012 01:15 PM

First, the heli they sold me had parts that didn't fit, i had to order from somewhere else to get replaced. Rather than replace the defective parts of a brand new kit they sold, they quoted me on the cost. A missing screw in the tail section for example, they told me the cost of a new stabilizer mount set because they don't have the screw that was missing (A heli shop that doesn't have screws???)

Second, the replacement parts they sold me didn't fit in the heli (See VWinRC thread). Either the shafts were too thick, screws were wrong size, or just plain didn't fit. Then they insisted that it was the right part and strongly implied that i was doing it wrong... a screw that doesn't fit in the hole as specified in the official VWinRC manual is MY fault???

And now this. A tail set they sold fried the helicopter. They said that it's impossible because the unit they gave me was sealed, totally ignoring the fact that they had to give me an extra propeller because the one that was also 'sealed' inside it was split!

#10 Hajile Nov 17, 2012 07:12 PM

1 Attachment(s)
The pic of the broken tail blade the tail set came with still in the pack

http://www.rcgroups.com/forums/showa...3&d=1353201012


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