Blown FET? on Scisky board. Need help ID'ing

Does anyone know what this is? It blew today in the middle of a backflip and killed everything, then I plugged in a new bat and everything ran fine for a few batteries until I crashed and ripped out a motor lead.

Circled and zoomed, right next to the positive lead.

Also, what are the connectors I can use to solder right into the board for PNP? I soldered some female mini jst’s to the board, but I’m not too happy. I want to steer away from direct soldering the motors to the board.

@Complacent1 I know you have an answer for me :slightly_smiling:

Im not a component guy! I rely on several of these awesome dudes for that. Here comes the @ train…


Do us proud you intelligent bastards!


Thanks! I’m hoping it’s something I can run without…?

Here are the motor plugs needed:

Or you can get them from MMW…


No can do @sykokenn…that is a FET and is a critical piece to the puzzle.
They can be found here:

@madman1412 is sitting on a pile of these and this might be a great reason for you two to get together since you guys live so close.

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Rumors say that @madman1412 is also pretty good with replacing FETs :wink:
The first thing I did to the scisky was soldering 1.25mm 2pin sockets to it, everything else looks even worse :wink:

Well since @madman1412 and I have been talking about getting together, it may finally be a good excuse for me to grab one of his AlienWii’s.

Can I ask why I’ve been able to run without it? Should I be concerned about causing major damage to the board with the few batteries I’ve run through it?

@Jtwalkz Thanks for the item with digikey, is there a proper term for the actual part? I’m trying to see if I can find it close and overnight some from ebay or something.

How easy would it be to pull a FET off of a Nano QX FPV board and install it on my scisky?

If it’s still working it has got to be on its last leg for sure…that sucker is about to go nuclear and if it does you could easily burn the pads and possibly the traces right off of the PCB. That would make an easy repair a little more difficult, if not impossible.

The part I linked is a N-Channel Mosfet or FET 20v 6.3 amp SOT-23


Do you have the proper equipment for that?
Please don’t break a working NQX board for that. Do what @Jtwalkz proposed.

@sykokenn: don’t fly that thing anymore.
since you know the right fets now, see where to get them or contact @madman1412. Wish I would live close to this marvelous guy too.
After fet replacement, make sure to solder on some proper motor sockets. And always check for shorts (multimeter is better than eyesight) after soldered them on. I assume you had a short on the rear right one. As you said a cable get ripped off. If this thing became loose before the massive crash this might be the cause for the short and burned fet.
Here’s an additional cheap source for those plugs from China:

Pssst, wanna buy a mosfet fella?

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Haha. We also put our skag on those small scales :syringe:

How do you know I am sitting on them @Jtwalkz!? haha

@sykokenn, we do need to meet up. I got this one for you :wink: I do have a stash like @Jtwalkz says and for sure doing a diagnosis in person is usually easier than through the forum and having to go rounds to troubleshoot. A FET is an easy fix and I have them on hand so if that is the only thing wrong with this then it will be a quick 5 minute repair. Like @las says don’t disable your nQX the FETs are 15 cents. I can also solder in some motor sockets for that.

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FET is easy. I remain unconvinced on the need for motor sockets (If you know how to solder)

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I do :wink: Have gotten quite good at it. I still prefer plugs over having to solder though. Soldering the wires direct does have it’s advantages though.

I vote for motor sockets - everything else is too optimistic :wink:


I agree @madman1412 sockets are my preference over direct soldering (having done both) especially on the Scisky.

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Oh I see how it is, I leave for a few minutes and NOW everyone’s talking without me!

Lol seriously though, thanks for all the advice. The only reason I suggested using the NQX board was because its trash anyway, has random brownouts and falls from the sky. But since @madman1412 has so graciously offered his expertise, I’m going to have to take him up on that.

And yeah, I don’t have the proper equipment to even attempt this with my amateur soldering skills, wishful thinking :slight_smile:

I’m not exactly sure when it failed now, because I had run a few batteries after a blackout, but I don’t think that caused it (or it could have been the start). I did some troubleshooting last night and direct soldered the motors to the board, the motor with the blown get just spools right up on power, so I’m sure that only happened on my last crash of the day.

Funny things these little machines are, but I’m having a blast. I’m about to get probably a handful more sciskys…for testing purposes :wink:

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