Blown new MOSFET controller!

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amberwolf   100 GW

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Re: Blown new MOSFET controller!

Post by amberwolf » May 16 2019 2:47pm

http://ebikes.ca Learn tab then Troubleshooting has information on how to test FETs and other stuff, but you will need an ohmmeter. Even a super cheap DMM like the ones they sometimes give away at Harbor Freight and places like that will do the job. You may not have any place like that around you, but the internet abounds with them. :)

In my experience when one cap has blown, the others are probably damaged as well (the same is often true of FETs) when they are all on the same power bus exposed to the same severe overvoltage event. So probably all of those large caps will need to be replaced, even though only one has actually vented.

If you did not have the "keyswitch / doorlock / ignition / etc " wire connected to battery positive when the event occured, then the low-voltage (non-fet) stuff may still be perfectly ok.

If you did have it connected, then almost certainly at least the input stage is damaged, and potentially everything down the line depending on how the components failed (shorted, open, etc) and how quickly events progressed.

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Re: Blown new MOSFET controller!

Post by Vikingimike01 » May 16 2019 3:45pm

Hey. I live in Europe, so no harbor freight, nor anything free.

I don't know about the keyswitch thing. I don't have one of them. I have to turn it on with a thing connected to the display. It's a button that has the up and down buttons to the assist levels as well as the mode. I had nothing else.

I'll maybe get an ohm meter depending on how the manufacturer can fix it for me.

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Re: Blown new MOSFET controller!

Post by wturber » May 16 2019 4:14pm

Vikingimike01 wrote:
May 16 2019 3:45pm

I'll maybe get an ohm meter depending on how the manufacturer can fix it for me.
It's a good idea to have a volt/ohm meter if you have an ebike that you might ever do some repair work on. They don't have to cost much.

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Re: Blown new MOSFET controller!

Post by Vikingimike01 » May 16 2019 4:49pm

Okay. I'Ll get an ohm meter.

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Re: Blown new MOSFET controller!

Post by markz » May 16 2019 5:51pm

Just one!?
:wink: :lol:
wturber wrote:
May 16 2019 4:14pm
It's a good idea to have a volt/ohm meter if you have an ebike that you might ever do some repair work on. They don't have to cost much.
Better then none!
Also get a few spare fuses, extra probes and a few 9V batteries.

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Re: Blown new MOSFET controller!

Post by e-beach » May 16 2019 8:08pm

A digital multi-meter has what you want. They don't cost much.

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Re: Blown new MOSFET controller!

Post by Vikingimike01 » May 17 2019 3:34am

Is a cheap 4-5 dollar one good from China, or should I go to my hardware store and buy like a 10 dollar one?

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Re: Blown new MOSFET controller!

Post by RunForTheHills » May 17 2019 9:50am

Vikingimike01 wrote:
May 17 2019 3:34am
Is a cheap 4-5 dollar one good from China, or should I go to my hardware store and buy like a 10 dollar one?
The hardware store version might include instructions in English.

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Re: Blown new MOSFET controller!

Post by e-beach » May 17 2019 11:06am

A 10 dollar one at the hardware store is probably the 5 dollar one from China. :wink:
What you want is a one of reasonable quality because it will be more accurate then the cheap one. The reason electricians use expensive meters is because they are accurate and durable.

However if your budget is tight, the one from the hardware store will be fine.

:D :bolt:
Favorite Quote: "This is L.A., sugar. There is no 'over the top." --- Chris Erskine

Current build: Liahona w/ cheap front suspension and suspension seat post. Yescomusa 36v 800w generic front hub motor. 15ah Headway triangle mounted pack. Tronsung 30 amp,

Previous Build:1992 Trek Antelope 800 - Bone Crusher (no suspension) - Yescomusa 800 watt 36 volt front wheel kit. Don't do it! Get suspension!!!

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Re: Blown new MOSFET controller!

Post by Vikingimike01 » May 17 2019 2:28pm

My budget atm is -75 dollars. So yeah.

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Re: Blown new MOSFET controller!

Post by RunForTheHills » May 17 2019 4:02pm

e-beach wrote:
May 17 2019 11:06am
The reason electricians use expensive meters is because they are accurate and durable.
It's either that or they don't want to be the only electrician at the jobsite that doesn't have a Fluke multimeter, Klein hand tools, and DeWalt power tools.

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Re: Blown new MOSFET controller!

Post by fechter » May 17 2019 4:22pm

It's handy if the meter also has a diode check mode. Usually there will be a little diode symbol on the dial if it does.
"One test is worth a thousand opinions"

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