WARNING: Gotway Nikola production (assembly) issue [Solved]

[Eliran]

Well, I think I'll buy a used KS16ish and on my next Shot Show I'll bring a Nikola with me from Las Vegas.

[Patton250]

30 minutes ago, Eliran said:

Me too. Im a.Vortex Optics, Zeiss optics dealer in Brazil and I can't even imagine to.answer a costumer like this. Ok. This is.life. 

Competition is very grateful on that 

Oh wow.  Now you and I have something else in common. I don’t do optics for a living but I have enough of them to supply a marine platoon. :-) 

[Eliran]

2 minutes ago, Patton250 said:

Oh wow.  Now you and I have something else in common. I don’t do optics for a living but I have enough of them to supply a marine platoon. :-) 

That's way toooo cool huh? Nice shootings my friend 

[Jim Martin]

I don't really know WTF to trust anymore with this damn NIKOLA.  So got the new board installed, powered it up, running great, fan kicks in and I'm thinking awesome wheel is working great and my fan works.  I'm rolling it back and forth and SNAP, CRACKLE, POP!  Wheel shuts down and what is that SMELL!  Did this new board just blow some MOSFETS?  Surely not!  I took the board out and opened it up.  Damn, something really bad happened!

[Rywokast]

4 minutes ago, Jim Martin said:

I don't really know WTF to trust anymore with this damn NIKOLA.  So got the new board installed, powered it up, running great, fan kicks in and I'm thinking awesome wheel is working great and my fan works.  I'm rolling it back and forth and SNAP, CRACKLE, POP!  Wheel shuts down and what is that SMELL!  Did this new board just blow some MOSFETS?  Surely not!  I took the board out and opened it up.  Damn, something really bad happened!

what in the F#CK!?!??!!! why is it missing screws? did you remove those?? are you planning to take it apart and inspect it? this is extremely disappointing........

[Patton250]

Oh no. Massively depressing. Sorry man. You didn’t fall? 

[Jim Martin]

6 minutes ago, Rywokast said:

what in the F#CK!?!??!!! why is it missing screws? did you remove those?? are you planning to take it apart and inspect it? this is extremely disappointing........

I did take it apart.  That's why it's missing screws.  The pictures are of the front and back of the board.

[Rywokast]

40 minutes ago, Jim Martin said:

I did take it apart.  That's why it's missing screws.  The pictures are of the front and back of the board.

oh ok so the screws aren't missing from factory, I guess I meant more like literally taking it apart to inspect the components, I mean why the hell would these fail when they have been perfect for so long on the MSX.. so confused.. surely it must be something different with the nikola thats allowing these mosfets to blow, maybe they just overextended themselves when designing the nikola giving it its relative zippyness and being allowed to draw more power.. was there any glue or anything on the pads? this looks identical to the original burnt boards what the hell is going on

Edited July 8, 2019 by Rywokast

[mrelwood]

Dear god... @Jim Martin, I can't see the thermal silicone plate in the pictures. Was it installed? If not, the Mosfets will short out via the aluminium cooling plate.

[Jim Martin]

2 minutes ago, mrelwood said:

Dear god... @Jim Martin, I can't see the thermal silicone plate in the pictures. Was it installed? If not, the Mosfets will short out via the aluminium cooling plate.

Yes, it was, I’ll upload a picture of it tomorrow 

[Marty Backe]

1 hour ago, Jim Martin said:

I don't really know WTF to trust anymore with this damn NIKOLA.  So got the new board installed, powered it up, running great, fan kicks in and I'm thinking awesome wheel is working great and my fan works.  I'm rolling it back and forth and SNAP, CRACKLE, POP!  Wheel shuts down and what is that SMELL!  Did this new board just blow some MOSFETS?  Surely not!  I took the board out and opened it up.  Damn, something really bad happened!

That really sucks. This highlights the fact that I don't believe Gotway tests the boards in any meaningful way. If they did my fan would be working and your board wouldn't have fried.

Now on the other-hand, boards do fail and have been known to fail when the wheel is first turned on. KingSong, Gotway, Ninebot, etc. It happens. You just got unlucky.

[Anagnorisis]

4 minutes ago, Marty Backe said:

That really sucks. This highlights the fact that I don't believe Gotway tests the boards in any meaningful way. If they did my fan would be working and your board wouldn't have fried.

Now on the other-hand, boards do fail and have been known to fail when the wheel is first turned on. KingSong, Gotway, Ninebot, etc. It happens. You just got unlucky.

So out of say 100 EUC that get sold how often does this happen? Also Gotway could save a little money and not put the "QC passed" sticker or at least update it with "Roll of the dice"

[Marty Backe]

1 minute ago, Anagnorisis said:

So out of say 100 EUC that get sold how often does this happen? Also Gotway could save a little money and not put the "QC passed" sticker or at least update it with "Roll of the dice"

I think it's less than 1-percent, but statistics are hard to come by. This isn't the first case I've read about, but it's rarely reported. I think if it was 1 out of 100 we would see more cases reported here.

[wheelr]

2 hours ago, Jim Martin said:

SNAP, CRACKLE, POP! 

 

2 hours ago, Jim Martin said:

I don't really know WTF to trust anymore with this damn NIKOLA

 

Yeah.. I won't be getting one of these for a while

Edited July 8, 2019 by wheelr

[Rywokast]

i am one more incident of any kind away from cancelling my nikola order, it is supposed to ship out this week, new batch from the factory.. but im really contemplating going with something else now.... i reeeally want the 2100 wh and if it was only the 1600 wh version i would have cancelled the order a week ago.. but is it worth it to have the thought in the back of my mind constantly that i could fry a mosfet and faceplant, smashing the wheel up at any moment???

[maltocs]

3 minutes ago, Rywokast said:

i am one more incident of any kind away from cancelling my nikola order, it is supposed to ship out this week, new batch from the factory.. but im really contemplating going with something else now.... i reeeally want the 2100 wh and if it was only the 1600 wh version i would have cancelled the order a week ago.. but is it worth it to have the thought in the back of my mind constantly that i could fry a mosfet and faceplant, smashing the wheel up at any moment???

not that the 100V Nikola Plus with the different boards have been TRULY road tested yet, but if are a rolling the dice type of person, you're odds are probably better with that one. They don't make a 2100WH version, but 1845 ain't too shabby.

[Rywokast]

22 minutes ago, maltocs said:

not that the 100V Nikola Plus with the different boards have been TRULY road tested yet, but if are a rolling the dice type of person, you're odds are probably better with that one. They don't make a 2100WH version, but 1845 ain't too shabby.

they might be, might not idk.. how many are out in the wild now, a handfull? ive only seen 7 orders on ali.. havent heard anything about the 100V really... i already have the 5A charger for the 84V so i would have to spend more money to get the charger which may or may not be wired improperly, and would probably come with a european plug like one north american buyer already complained about on the review.. plus 1845 wh, the smaller sized ks18xl can probably get better mileage and for less money.. i very wary to trust any nikola now 100V or not... unless this issue is definitively identified (which i THOUGHT it was, but now cant be sure) and can be totally assured that its something that cant happen on the 100V, i dont trust it any more right now.. i mean ive seen multiple reports and pics here and FB of people getting boards different from the next person, martys fan not working same with another person, wiring not matching.. like are they just completely inept? maybe its just how the nikola motor is tuned, or something in firmware or elsewhere on the board that allows it to draw way more amperage and blow a mosfet i dont know

Edited July 8, 2019 by Rywokast

[Marty Backe]

1 hour ago, Rywokast said:

i am one more incident of any kind away from cancelling my nikola order, it is supposed to ship out this week, new batch from the factory.. but im really contemplating going with something else now.... i reeeally want the 2100 wh and if it was only the 1600 wh version i would have cancelled the order a week ago.. but is it worth it to have the thought in the back of my mind constantly that i could fry a mosfet and faceplant, smashing the wheel up at any moment???

Go with your gut. If you aren't comfortable with the wheel, what's the point in spending your money on one? There are plenty of fun wheels to be had out there.

[Rywokast]

Just now, Marty Backe said:

Go with your gut. If you aren't comfortable with the wheel, what's the point in spending your money on one? There are plenty of fun wheels to be had out there.

my gut tells me not to, because in my mind i know for a fact i aint gonna be suiting up like iron man every time i want to ride it... but my male brain is fighting me on it lol

[maltocs]

54 minutes ago, Rywokast said:

they might be, might not idk.. how many are out in the wild now, a handfull? ive only seen 7 orders on ali.. havent heard anything about the 100V really... i already have the 5A charger for the 84V so i would have to spend more money to get the charger which may or may not be wired improperly, and would probably come with a european plug like one north american buyer already complained about on the review.. plus 1845 wh, the smaller sized ks18xl can probably get better mileage and for less money.. i very wary to trust any nikola now 100V or not... unless this issue is definitively identified (which i THOUGHT it was, but now cant be sure) and can be totally assured that its something that cant happen on the 100V, i dont trust it any more right now.. i mean ive seen multiple reports and pics here and FB of people getting boards different from the next person, martys fan not working same with another person, wiring not matching.. like are they just completely inept? maybe its just how the nikola motor is tuned, or something in firmware or elsewhere on the board that allows it to draw way more amperage and blow a mosfet i dont know

Lots of variables! I'd I were you, I'd wait a few months until the factory fine tunes their product. Or buy something that's already tested. Tried and true is better than black and blue! 

Since I'm not you, and I'm somewhat of an early adopter (gambler), I'll let you know how the 100v/1845WH version is in a couple of weeks 😀

[meepmeepmayer]

Well... at least it wasn't glue!

Maybe this is just a very unlucky coincidence. I hope it's nothing with the Nikola itself.

2 steps forward, one step back...

[Rywokast]

welllllllll what do you know, i just got informed that my nikola has shipped lol.. i guess the decision has been made for me xD i will be inspecting the board and internals with a microscope, then find some padding and stress it as hard as i can

[Smoother]

3 hours ago, maltocs said:

Tried and true is better than black and blue! 

@Jim Martin So sorry for your loss.......................................of faith in Gotway.

 

2 hours ago, meepmeepmayer said:

2 steps forward, one step back...

Hmm! Now where have I heard that before?

5 hours ago, Anagnorisis said:

Also Gotway could save a little money and not put the "QC passed" sticker or at least update it with "Roll of the dice" 

Meet "Dirty" Harry Gotway

 

Edited July 8, 2019 by Smoother

[Arbolest]

6 hours ago, Jim Martin said:

I don't really know WTF to trust anymore with this damn NIKOLA.  So got the new board installed, powered it up, running great, fan kicks in and I'm thinking awesome wheel is working great and my fan works.  I'm rolling it back and forth and SNAP, CRACKLE, POP!  Wheel shuts down and what is that SMELL!  Did this new board just blow some MOSFETS?  Surely not!  I took the board out and opened it up.  Damn, something really bad happened!

 

Let me preface this by stating that I have a propensity for jumping to conclusions, so someone stop me if I get ahead of myself! 

 

I was examining the high resolution versions of the photos and noticed some weird silvery stuff around the left two MOSFETs on the upper row in the first picture.  As much as I think on it, I can't seem to come up with any really plausible ideas for what that stuff could be..  It looks conductive (almost like melted metal or a metallic paste), and if it managed to come into contact with the heat sink, then I feel like it would have shorted out that pair of MOSFETs and blown them almost instantly. Unfortunately for that theory, I kind of doubt that it would be any kind of thermal paste because the silicone pads were installed on it (there would have been no need). Also, from the way it appears in the photo it seems like it might have actually come OUT of the packages of the blown MOSFETs, which means it almost certainly happened post-failure. Because of this there is a little voice in the back of my head whispering that it may actually be melted silicon, although I've never heard of this happening before...

Now, as to the reason that both of those MOSFETs failed instead of just one of them, let me confirm some of the theory behind how the board operates ... I'm pretty sure that I understand the circuit layout for the part of these boards concerning the MOSFETs, but someone please correct me if I've missed something important... There are two side-by-side rows of MOSFETs with each row being broken up into 3 pairs. Each pair is just two MOSFETs wired in parallel for better current handling. A pair of MOSFETs in one row is mirrored by a matched pair of MOSFETs in the other row, and together the two pairs control the power for a single phase of the 3-phase motor. The reason that both of these MOSFETs blew is because the pair in question was controlling the same phase of the motor and when the first one blew the second one suddenly had to handle a lot more current than it was meant to on its own.

That all makes sense to me and tells me why and how the MOSFETs might have failed, but not the underlying reason, and the only unique thing I can see here is that silvery stuff, and I think it's likely significant. If it was something external, then I would point it out as a root cause, but I need some more information before I can feel certain about that.

Anyone else have any other leads?

[Planemo]

1 hour ago, Arbolest said:

I was examining the high resolution versions of the photos and noticed some weird silvery stuff around the left two MOSFETs on the upper row in the first picture.  As much as I think on it, I can't seem to come up with any really plausible ideas for what that stuff could be..  It looks conductive (almost like melted metal or a metallic paste), and if it managed to come into contact with the heat sink, then I feel like it would have shorted out that pair of MOSFETs and blown them almost instantly.

I always thought that the casing of the mosfet was a common ground (also linked to the centre pin) so it would make no odds if the metal back came into contact with the heatsink, ground, negative or whatever. Also the reason why the fixing bolt doesnt need to be insulated either.

Thats certainly how I have always wired fets. Maybe GW wire them differently...