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ACM+ 1300Wh cannot turn off, very loud mechanical clicking while tilting wheel forward/back - replace mosfet or other problem?


dongie
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So I made a mistake of letting someone random try and ride on my wheel and they promptly nearly fell off from it, the wheel spin out, there was no smoke, but it lost all forward/reverse going power and cannot be turned off and any forward/reverse motion is accompanied with very loud mechanical-ish clicking (but when battery is unplugged, wheel spins smooth).

I was told by a friend familiar with this that it's probably blown mosfets due to overcurrent (mine is 84V/1300Wh version), but I'm not sure why that doesn't allow it to turn off.

Anyway, I've got a replacement main board on the way since its under warranty still but I'm curious if I can patch up the existing board meanwhile.

I have some IRF100B201 laying around - is it worth trying to replace and hope nothing else is blown on the board, or just wait for replacement and don't worry about it too much?

As I haven't taken the board out yet I can't tell if its the 6 or 12 mosfet version (if it's 12, I can't see the bottom ones while the board is still in case). The wheel is new, manufacture date somewhere around july/aug 2017 (I forget). The motor is connected by 3 bullet connectors, not the XT 90 I saw in some pics. Not sure if that signifies old board or not.

Anyway tl;dr - try replace mosfet and see if works, or just wait for replacement and toss this one? Thanks.

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All 84V ACMs are 12 mosfets. Only the very first 67V ones had 6, like for a month or so. Motors should only connected with bullet connectors regardless of date (but I've seen some exceptions, no idea what they mean), XT90 was for the batteries. August 2017 should be the latest hardware iteration of the ACM anyways.

You can certainly try and connect a new mosfet, won't cost you anything. But for safety reasons alone I'd get the new board installed.

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I'm wondering why it blew (supposedly) in the first place. Also, if a mosfet blows ( = shorts the motor), shouldn't the tire still lock even if the battery is disconnected? Not sure. Open the thing up and have a look. Some photos would be nice if anything out of the oridnary is to be seen.

Edited by meepmeepmayer
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18 minutes ago, meepmeepmayer said:

Not sure. Open the thing up and have a look. Some photos would be nice if anything out of the oridnary is to be seen.

Yeah. I was avoiding having to take it apart because the white goop was everywhere and super annoying to try and detach.

Anyway, I finally got through all that and took the mainboard out - and I guess the problem is found:

photo_2018-01-04_22-18-21.thumb.jpg.becf6d3aa4e4bedee4494bc450540ce4.jpgphoto_2018-01-04_22-18-27.thumb.jpg.c3070b9880ff345ab2409d5ecc2d580e.jpg

So it is one of the bottom fets (top looks clean, at least nothing smoked).

20 minutes ago, meepmeepmayer said:

I'm wondering why it blew (supposedly) in the first place.

I'm not sure. I was standing near, this was indoors in a hall btw, the dude falls off due to unbalance, the wheel spins up and falls on the side. That's it. After that can't turn off and clicking.

 

21 minutes ago, meepmeepmayer said:

. Also, if a mosfet blows ( = shorts the motor)

I guess this one blew up open? Or I donno.

 

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Well, it's a blown mosfet:efee47c9c8: Thanks for the photo.

I suspect the board was bad (close to dieing) from the start. They should not blow unless you lock the tire or anything harsh, not from simply falling to the side. But we had some strange mfet blows just from a tiny twig or so. So it can happen.

Better now than cutting out during a ride. You still have the board relacement work, though. Well, Gotway. Not much to add:efee8319ab:

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21 minutes ago, meepmeepmayer said:

I suspect the board was bad (close to dieing) from the start. They should not blow unless you lock the tire or anything harsh, not from simply falling to the side. But we had some strange mfet blows just from a tiny twig or so. So it can happen.

Yeah I don't know either. Thanks for confirmation.

So do you think its worth trying to replace or there could be other stuff bad on it?

I'm worried about the not turning off part - would it also happen when a fet blows up? Most posts related to this I see talk about hall sensor plug falling out or etc.

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3 hours ago, dongie said:

Yeah I don't know either. Thanks for confirmation.

So do you think its worth trying to replace or there could be other stuff bad on it?

I'm worried about the not turning off part - would it also happen when a fet blows up? Most posts related to this I see talk about hall sensor plug falling out or etc.

I dont understand what you mean by "not turning off"....

Do you just mean the tire  is blocked? thats normal for a blown mosfet! 

Or do you hear the "whistling sound" and really the board is working and cant be turned off?

Whatsoever: I dont know anyone hear who replace only one or two mosfets! Normally a board change is done in case of a Mfet blow.

And yes, something other as the Mfet might be defect now, too!

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10 minutes ago, KingSong69 said:

Or do you hear the "whistling sound" and really the board is working and cant be turned off?

Yes, there's high frequency whine ( same as normal operation ) but board cannot be turned off until battery is disconnected. No matter how long I press the power button.

I had to take it apart to power it down.

The wheel is spinning freely when there's no power, and does click-clack when there is - sorta tries to spin but gets stopped very quickly.

 

Anyway will just replace entire board when it shows up.

Edited by dongie
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9 hours ago, dongie said:

Yes, there's high frequency whine ( same as normal operation ) but board cannot be turned off until battery is disconnected. No matter how long I press the power button.

I had to take it apart to power it down.

The wheel is spinning freely when there's no power, and does click-clack when there is - sorta tries to spin but gets stopped very quickly.

 

Anyway will just replace entire board when it shows up.

When I blew a MOSFET on my ACM, the wheel also would not turn off. Had to replace the control board. I suspect that when a MOSFET blows that there is ancillary damage elsewhere on the board.

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Update:

 

My replacement board arrived, and it contains the "HY3712" fets instead of IR.

Best source of info I could find was @ http://www.thunderind.com/plus/view.php?aid=271

VDS is better than IR (125V) but probably most other spec is crappier. Oh well, I'll find out when I fall off this thing I guess.

Code is now 180104xxx

Edited by dongie
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