Finding and Replacing Blown Motor Controller Mosfets

[@ncm805]

Thank you for the video! Helped me find and switch out a bad mosfet that went bad after a month. FWIW the replacement part for mine was IRFB 3607. Mine also was a negative mosfet but different location than in the video. Moving the mosfet back and forth until it broke off made it a lot easier to hold one leg with pliers and then heat it on the back side until it could pull out. Cleaned out the hole with Chem-wik, right stuff for the job, and in with the replacement. I was able to isolate the correct phase wire by disconnecting each phase wire in turn while rolling the bike backwards. Once the correct phase wire was disconnected, bike rolled backwards easily. Prior to that rolling backwards required more effort indicating a problem (as well as an E9 error code) Bravo - Thank you for your instructions!

[@siaseeds8950]

Dude. We need more humans like this gentleman on this earth. I have a Blix Vika+ that failed on me and I called the manufacturer. Talking to them was about as useful as talking to a sack of potatoes. This dude knows exactly what he is talking about.

[@hjeffwallace]

I’ve only built 2 ebikes, but have already replaced 2 controllers. Now I’ll see if I can fix them!

[@81formann]

If possible, its often easier to cut the legs and remove one leg at a time. Might not save everyone a lot of time in cases like this, but its safer and easier for those unskilled or working with less than ideal tools. A weak 15W soldering iron or an oxidized tip might end up taking too long, and before you know it the traces just come right off the board. Nice video. Blown FETs is a common problem and fixing it is something most will be able to handle. Especially if they have some soldering before.

[@jeffreymorrison2208]

good video, the diagnostics in the beginning were helpful. I would recommend replacing the heat sink compound or at least mentioning it as this is very important in an electrically isolated heat sink. also, the wattage of your gun is important with mosfets as a lot of heat is sucked away by the large traces and the center leg. probably would have fallen out if your gun was hotter. :)

[@cliffwisser9077]

Thanks Phil for the video. I have identified several blown Mosfets after seeing your video. I have a chinese controller with 12 Mosfets. No markings to identify them. Can you tell me what Mosfets I need, and where to get them? I have a 48V, 26amp controller.

[@kevmatt8450]

good luck

[@sidsnot7850]

Excellent educational video but would have liked to see the heatsink compound replaced.

[@doni20091]

Boa tarde Amigo .super legal .parabéns por compartilha seus conhecimentos. Vou ver todos os seus vídeos valeu td de Bom..

[@34Merlin]

Thanks so much this helps I have two go out on me and the comment on the movement of the tires helped that is what caused my issue

[@BowensBlvd]

Exactly! Every time I searched what the problem was nothing could give me anything related to my issue

[@molifehacks5258]

Question... I shorted out my controller by touching the positive and negative wires together on the controller. I opened it up and there is a black burn spot next to the positive and negative area inside the controller. Now my controller no longer works. What could be problem? Thank you

[@molifehacks5258]

@@jb9072 controller was not connected to the battery.

[@AndreLuiz-ip3fh]

Isn't better to change all the 6 Mosfet? Even using an higher current model?

[@abood533]

I have a question about the replacemnet Mosfet. Should it be exactly matching the old. Or I can use something with in range? I have 6 mosfet controller 32V, 250W controller. Can I use 49A 55V Mosfet?

[@GrinTechnologies]

In general it's a good idea to try and match or do better for the Rds ON resistance, and also the total gate charge or gate capacitance. Both or these specs are well documented in the datasheet for any given mosfet model. What you don't want to base in on is nominal amperage. Saying 49A doesn't mean anything really since the current handling depends massively on the extent of heatsinking, you want to look at the fet's actual electrical characterization.

[@heinzrhizo6652]

hello, if I give full throttle (freewheel) or put a little load on the engine, everything turns off. When I then disconnect the battery, I measure 32v on the controller side which then slowly drops. And reconnecting the battery (note a spark at the battery contact), I can start up again. could it be that my battery is too small 36v for 11max20A controller 36v direct drive motor. thank you.

[@GrinTechnologies]

Sounds like a tripped BMS. 32V is quite flat for a 36V nominal battery pack so you might want to try charging the battery first.

[@Bergwacht]

my battery cable fell of so the kers burned anything on my controller. sadly i dont think that replacing mosfets will help if the esc just does nothing anymore, even the scooter doesnt turn on anymore. I have a functioning replacement controller but it's from a german 20 kmh m365 clone, and just the tail light flashes ... so i have to replayce broken parts but what for parts?

[@pooroldman9762]

what kind of electronic did you study ? my son is incomponent ,i must do a dna test on him , i wish he do something like that ,bikes are going to be big in future

[@stevemcgowan3017]

its the yellow phase wire on power resistance test thats zero reading on negative test it starts off zero then slowly builds up to the other phase readings or up to 5kohms.i have my old 48v controller will try that soon im just waiting for some jst sm connectors to connect hall sensor back up .steve in uk

[@dgb5820]

Outstanding easy to understand video

[@kevmatt8450]

Why are all of these videos from over 2 years ago when these scooters are more popular now than ever?

[@Matanumi]

Because thats when these all came out

[@lenkasendecka183]

Great video. I have the same controller as in the video and my motor just shudders and then stops when powered up. I get about 5 kohm's between battery -ve and 2 of the phase wires but only 1.8 kohm on the 3rd phase wire. Is this too low and could one of the mosfets be my problem? Resistance builds as expected on all 3 pahses against battery +ve. I've checked hall sensors and windings on motor itself and they are all good. Thanks for any help.

[@AlexYeryomin]

I had a broken motor controller a couple of years ago, and thanks to this instructional video I managed to fix it. Now I got another one, immediately found this video and fixed the controller. Thank you!

[@Cyberbikesau]

Great repair guide. Justin and the team from Grin Tech are the best in the industry!

[@RoySATX]

Pretty good. I'd have applied new thermal paste, at least to the replaced MOSFET, and cleaned the flux off the board, both would add life to the controller which is, after all, the point of this exercise. Maybe you did, but you didn't mention or show either before stating it was finished and closing it back up.

[@GrinTechnologies]

Yeah the best thing is actually to replace the kapton tape strip with an ACTUAL thermal isolating pad that has much better thermal conductivity. The cleaning of flux residue doesn't have any consequences one way or another.

[@ncmach1]

My KT sine wave controller has 18 mosfets. Looks like the blue phase is shorted. Now, looks like I have to de-solder 3 of those fets? Oh boy. CRST041N08N and where to buy?

[@GrinTechnologies]

Yup, only one may be blown but you can't easily tell which it is. No need to use an identical replacement, a comparable mosfet with similar gate capacitance or gate charge and similar or lower rds on will usually work fine as a substitute.

[@nb1843]

using the wrong tip is one way of not doing it right.

[@odoohub5010]

What causes the mosfet to fail? is a lesser amp controller more likely to fail than a bigger ah controller?

[@sausagefingers714]

i just taken a reading on all 6 of my mosfets.. 2-6 all have a climbing voltage reading. but number 1 has a voltage spike on first contact and then begins to fall? is this the problem im having? when the system is live, its feeding 5v to all phases at the same time.. even when i apply the throttle, the voltage on all phases just sags to 0.3v and the motor makes a tiny humming sound.

[@theebikeguy3852]

Not sure if you will even respond but. I ran a test on the controller with a ebikes tester it showed all ok when I use my Ohm meater Ground prong to controller to 3 phase (green 9.07) (yellow 9.06) (blue 9.04) neg prob to positive controller the 3 phase wires all read 00.0 bad Controller??

[@jhonny001]

Hi Phil, really nice and helpful video. It helped me find the faulty MOSFET in my controller. However, as soon as I plug the battery connector and try to accelerate, the same MOSFET is failing... I've replaced the same twice... Any ideas?

[@justinlemireelmore]

That usually means you also have a blown or damaged mosfet gate driver circuit unfortunately. and fixing that requires much more specific knowledge of your particular controller PCB. We find that in about 2/3's of cases with controllers that have a blown mosfet it can be fixed just with the mosfet replacement, but about 1/3rd of the time there are problem that have propagated further upstream and replacing a FET alone isn't enough. .

[@jhonny001]

@@justinlemireelmore Thanks Justin! It is a 22A KT controller from Aliexpress... Probably one of the most common ones... The rest of the components in the board look OK... I also tested a couple of capacitors of that same phase...

[@sdiburro1]

I have a swagtron envy bike I think the motor is only 200 watts it has a small motor controller in it. I was having problems with it when I got a 14 amp battery at 36 volts that battery that came with it was only a 4.4 amp battery at 36 volts mine keeps cutting off the power and the display malfunctioning going crazy then I noticed the controller was getting hot is it because the battery has more amps in it how will I lower the amperage do you think I might need a new motor controller

[@stacycollinsworth2092]

how I tell what kind of electric scooter I have when it's not identified on the frame

[@DallasAya]

Cool video, I think you may consider wearing a bicycle helmet with alien blinking strobes for theatrical effect

[@thekillerdog5228]

You know what i never ask for help but... please does anyone have any ideas! I have a scooter i purchased $100 secondhand broken! Its a replica of the s11 leqismart, i got a new battery and the controller flashes red slowish speed, when the power button is pressed. Upon release nothing! No display no deeps nothing! If i hold the pwrbttn it keeps flashing aslong as i hold it😅

[@slugger5358]

Does anyone know where i can purchase the controller? I have a model # ST027A-ST890-800A The capacitor blew up and damaged the circuit board.

[@cleangreen2210]

I am worried I blew my new Kelly KLS 7275H. It was working, but when i wired the potentiometer, there was a ZAP and now I dont have power to the phase wires. Can it be fixed?

[@cleangreen2210]

I see power between B+ and B- and at the end of the fuse between + and B-. I just don't see power anymore between B- and the phase wires. Please help!

[@GrinTechnologies]

Anything can be fixed if you have the ability to identify what is wrong and replace it. But very few people have that skill set for random bldc motor controllers. Generally your first course of action if you don't have those skills would be for you to contact Kelly controllers or the vendor you bought from, and see if they offer repair services.

[@GrinTechnologies]

It's very unlikely that anything you did to the potentiometer input signal would have blown the controller MOSFETs, which is what this video is about.

[@cleangreen2210]

@@GrinTechnologies thanks for the reply. yes few of us study BLDC motor controllers that in depth. I thought perhaps you had some troubleshooting steps to narrow it down. Kelly hasn't responded yet.

[@TorontoPopulistConservative]

5:45 Just realized why the screws for those mosfets have those insulators. I was just thinking of screwing a mosfet in without the insulator today. Thankfully I didn't do it.

[@miketipton678]

So, how much time to line up the long bar that locks down the mosfets? That part can be a bear to put back in.

[@GrinTechnologies]

It's not too bad if you solder the mosfets all at the same height and all with their legs vertical. Failure to do that though, and you could be in for a small alignment challenge...

[@stonecoldkill40stinecoldki54]

Great video I appreciate brother!

[@armenvegas]

Great video. My controller/motor on my kart struggles to get up to 10mph, but runs perfect after that up to 30mph. Have you ever had that type of situation? Thanks

[@atdit]

Is it sensorless?

[@armenvegas]

@@atdit no its sensored, I dont know if magnets are chipped, or controller mosfits are bad. I dont want to open and ruin while it some what works

[@pauloa.7609]

@@armenvegas any solution for this problem?

[@armenvegas]

@@pauloa.7609 yes I was using a sinusoidal controller as opposed to the cheap controllers that come with these cheap motors.

[@TROUROCKS]

ed lyen makes the best value controllers at good prices

[@popeyegordon]

This is truly bizarre. Mosfets are extremely static sensitive and this guy was wearing HEAVY DUTY RUBBER COATED WORK GLOVES!! In 40 years of electronics work I have never seen anyone do that. Gloves do not stop built up static electricity from ruining the part, especially in low humidity. Heavy rubber gloves are only used professionally in high voltage work on live wires. It is dumb luck he did not blow the mosfet with static. You need a technician's grounding mat and a wrist strap to keep your body at the same potential. Open the replacement part's packaging while it is laying on the mat.

[@evanzino1972]

Scooter ControlleI apologize, I have an error on the accelerator, the computer no longer works. an exclamation mark appears on the display. what is it about?rs

[@832738]

was going crazy trying to diagnose my scooter it was throttling weird i think the controller was damaged. when at full throttle it would make the motor jerky and loud and very slow. guess it wasn't the haul wires after all

[@rickylakemusic]

Does anyone know why my 1000 watt 48 volt front hub keeps going into reverse? It'll spin properly for a bit then inexplicably reverse. PI cannot figger it out.

[@GrinTechnologies]

Likely an intermittent signal on the fwd/rev input of the controller. Could be from water ingress messing with the digital input signals, or from stray stands of copper around the connector.

[@armenvegas]

How about no power on a sabvoton controller? Worked for ever and now no power. Switch wire when touched to positive battery line, minisparks but it doesn't kick sabvoton on anymore. Any where I should look first?

[@GrinTechnologies]

Probably not the mosfets which is what this video is about. Putting V+ accidentally on your control signals can wreck all kinds of havoc on the logic board so you should probably be looking at where you can buy a replacement unfortunately.

[@abood533]

Many thanks for the nice video. The way you described the symptoms at the beginning is perfect. Now I can fix my bike thanks to you

[@BradWillis]

I have a Charly scooter which is made in Germany, although I have the less common 110 V US version, And appears that the controller box is fried. Is this something that you might be able to repair? The LED display does show a problem with the controller, and there is resistance when I try to turn the wheel by hand. Further, the motor does still work when I power it directly.

[@roamingeyesvision]

What will be the result if I replace 85v 150A mosfet ( k150e09ne- 18 nos) & 63v caps with 100v 200a (SSF1006 mosfet) & 100v Caps. Controller is 48v 45a...

[@edwardgilmour9013]

Why do Americans have so much trouble pronouncing the 'L' in Soldering ?

[@killack4944]

Hi, I have a question to ask. Today I was going to charge the battery of my 72v 40amp 8000w and once I plugged it it short circuited, are you able to tell me what is gone? So I turn on the scooter and the volt meter on the scooter is going down really really fast? Can you help me? Thank you Sir

[@Ghost-ri7bg]

hello guys im having an issue find the same controller was thinking to try fix it or can i use another one and put the right conectors and how do i trace wires if there diffrent colours?

[@MrTimmmers]

I saw a video where he used a thin wire to make a hole in melted solder for new components. Might help? kzbin.info/www/bejne/l4Wvc6KimdSMmKc

[@TnTckoo]

Hi dude, i have bad controller, but i check 3 phases and there is no problem. So i try check resistence betwen mosfet legs and i find one with diferent resistence - shorted circuit with no resistence. you think that mosfet is broken? And when is 80V/170A i need stick with these volts and amps or can be different? how much if yes? 75V/160A? Rds same or lower and Total GATE charge same or lower? thats all what i need to know when replace this mosfet? thanks dude

[@roncooke2188]

Hi Would you know of a replacement for these mosfets AB431A M317

[@pcfastonroad6104]

Hello maybe you can help me I have a problem on the headlight of my e-bike: it is always on but weak, when I turn off my bike, the light is a little bit stronger but still very weak, it is impossible to turn off the light unless I remove the battery. When I put the battery back, the light is again always on and weak. Is it a problem from the headlight or from the controller ? My bike is a Lankeleisi X2000+ Any help is very welcome, thank you in advance.

[@GrinTechnologies]

You are best to get support from the store who sold you the ebike. They should know the internal wiring and have access to necessary replacement parts

[@YouCantNow]

Hello I have a controller but k1 and k2 to increase speed not working, when is the problem

[@Chrisworkshop]

Hello, I have a controller 36V with one Mofset dead exacltly like you show in your video. The mofsets inside this controller are called S68N08R-A from Si tech. I don't have another one here and I don't know where to find one to replace the dead one. But I have 12 mofsets from a destroyed overboard wich are called 100N8F6. Do you think it is possible to use one for replace the dead S68N08R mofset?

[@Chrisworkshop]

After have take a look at the datasheets, the RDSON is almost similar 6,5 milli ohm for the S68N08R vs 8 milli ohm for the 100N8F6. But for the 100N8F6 the total gate charge is 100A (instead 80A for the original Mofset) and the rating voltage is 80V (instead of 68V). Knowing that, do you think it is possible to replace the S68N08R by the 100N8F6? (Sorry if the answer is obvious, but I am not an elelctronician so I need some help to be sure). If not I thougt at an another solution. Do you think it is possible or better idea to replace the 6 orginals mofsets by 6 mofsets 100N8F6 so that they are all identical?

[@Chrisworkshop]

So, I got no response but I made it and it works fine. 100N8F6 moffset taken from an overboard can replace a S68N08R moffet. I hope it can be usefull to somebodies. Bye

[@GrinTechnologies]

Good to hear. Normally there is a decent allowance of mosfet specs that will work on a given controller PCB and a given gate drive. No harm in just trying out a substitute fet with similar-ish specs if that's what you have.

[@steventaylor6364]

Hi, are all the mosfets the in the controller the same? or are there 3 negs and 3 pos? I have an ebike controller with 1 mosfet blown and all mosfets have same number on them, I cannot find these to replace, the number is ZJ7080. The controller is for a 48v 250w bike, controller says 15amp max current.

[@GrinTechnologies]

There are 3 high side mosfets, and 3 low side mosfets, but usually they use the same part number for both. Most likely you what we would consider a pretty crappy mosfet in a low current controller like that, typically 8-10 mOhm of on resistance.

[@kimroyful]

My scooter have 12.6v but no power could this be the problem with it ?

[@manuelcardoso8045]

Thank you for this video. After seen this video, I’ve found that is my problem. MOSFET. But they are 24 . It is a little bit hard for me to fix this. Can you do for me?

[@GrinTechnologies]

Nope. If doing it yourself is outside of your skill set or comfort zone then we'd recommend you get a replacement motor controller form the company who sold you the system in the first place.

[@nemracfiftyto6206]

My e bike mobility scooter has no brake lights and no reverse, could a bad controller be the cause.?

[@andykerr3803]

Wow, using a connector that shows nothing... 👏 👋 PS meaningless.

[@thesmuler5627]

I’m my case the solder actually melted and shorter the source/drain trace. So also look for melted solder sometimes mosfet can handled load but not the solder board. I packed that thing with solder to allow more current

[@hawaiirealtorandrewellis4701]

Somehow I managed to Burn out 2 new controllers when just hooking up to the battery. I get no readings back when testing positive side, only negative side readings. And when putting the leads on both Positive direct to Negative I get nothing. Ever heard of this? New 60v battery is putting out the right current. Controller is supposed to handle up to 72v and 45amps 2000-3000 watt motor. Briefly worked but after unplugging and plugging battery to controller a few times with a decent spark at connector it fried the first one so I tried the second controller thinking it was a fluke and same thing. Ugh! Any thoughts? Hate to see this happen again. I'm going to get a spark resistor for the next one but sounds like that likely isn't the problem? Thank you

[@ivanbrz83]

Hi. I have a scooter on Ms energy neutron n2 plus which has a 36V 15A controller. There is a problem it will not turn off on the button. You have some idea how to solve this. Thank in advance.

[@GrinTechnologies]

Yup, but it's not really related to the controller mosfets or mosfet replacement.

[@stacycollinsworth2092]

How can I find out what kind of electric scooter I have would it not be in marked on the scooter or the blame it all

[@mypower7853]

Sir i m not getting the same mosfet G067N07 n-channel what should i do

[@johnykool59]

Hi My grandsons xiaomi has stopped working dead. The video you made has been a great help as its the first time working on these. The connector to the motor has melted so I presumed there's a short in the wiring or motor. Could you please confirm i am on the right track with that. Thank you.

[@GrinTechnologies]

Usually a melted connector is not the result of a short anywhere but simply the result of too much current through the connector for too long. First try just bypassing the connector and hooking up the wires directly to each other to see if it otherwise still works fine, odds are good that it will.

[@FactsMattersUSA]

Just replace the controller. It’s only $26. Why waste the time.

[@jesp999]

Im trying to diagnose my nanobot d4+ 2.0 scooter. This problem does not happen in the cold morning on my first ride but happens in middle of day when it is warmer. Im in NM. What happens is both motors cut out when I'm in dual mode and when i go full throttle, and also sometimes when i try to just accelerate quickly. when it cuts out i does not come back alive by simply backing off a little on the throttle but i have to totally go back to 0 or no throttle and then the motors start if i re-engage the throttle more gently incrementing the speed. It does not happen in single mode when in just rear hub drive. When in single mode i can press the throttle fully and as quickly as I like. If I think of the thumb throttle as a clock that goes clockwise from 12 to 6. it is at the 5 when the motors cut out. It also happens if i got from 12 to 3 very very quickly. I'm pretty techy and i can replace of fix most anything but I like to diagnose first. I did have an extra thumb throttle speed controller so i did decide to replace that (because a year ago i brew out its usb power port when making a dual charger for a camera i have) but changing that speed controller had no change in the symptoms. Do you think there is a short somewhere in the system on full power or is it a hall sensor. Is it overheating and the bms cutting out? There are two controllers in the scooter with a communication wire between them, could one of the controllers be off. Both motors shut off when this happens. What tests should i run to see where the problem is? I have opened up the scooter before because I silicone sealed everything to protect from water. but actually moved to NM where there is little rain and I do not ride it in mud or water anyway. Any help appreciated.

[@tikshow87]

What if I changed the mosfet but the motor rattles like hell? Everything seems okay expect that noise.

[@GrinTechnologies]

Then assuming that your hall/phase poinout is correct, it would most likely mean that something is damaged on the gate driver circuitry associated with the failed mosfet, which can be a lot trickier to repair since then you are doing SMT rework and have to reverse engineer more of the PCB to try and identify what needs replacing.

[@billyjenkins3015]

I have a 48v Brushless Razor mx650. My problem is the motor only runs when you rotate the drive gear to a certain point. Do you think I might have a bad mosfet in my controller?

[@pietypereira8239]

The pedal assist wiring shows positive +5V and signal wire + 4.6V. Please any help. What can I replace? The throttle works fine. Except the pedal assist not working. Please advice.

[@ovi_4]

Your soldering iron tip is way, way too small and thin for such a demanding job. There is not enough thermal mass to maintain the heat. My advice, use another tip that's minimum twice the size of your current one.

[@maukaman]

Super helpful video! Lots of good information for working with mosfet controllers in general. Thanks!

[@Tom-p5v]

I've got same issue, I've established the issue is on yellow phase however my multimeter is ancient and has no beep noises... what should I be looking for on screen in terms of finding the offending mosfet? There are 5 per phase on my controller

[@firstcutvideos3111]

Any link to where I can buy these Controller Mosfets

[@ibbredeh777]

Hi please can you look into my case I got about 6 blown controller I watched your video and tried to fix by testing if any mosfet is bad just like one of your video but luckily all are good So what do you think is the faulty parts . Note some of them are reading high voltages more than as it should Please guys I need a help to.

[@Toobula]

Nice. Tiny comment. spinning motor doesn't QUITE prove you have good phase signals. I'd grab it with the glove and convince myself the torque is good.

[@ideafromkurdistan5257]

Good mr. please my throttel not run maybe lost mosfet or short ?

[@trevorjames5493]

Hey thanks for the video it helped me do some troubleshooting just had a question for you so if I'm getting continuity from battery positive to two out of the three phase wires, and continuity from battery negative to the third phase wire, does that mean all 12 of the mosfets are bad? I'm also getting continuity from the positive battery connector on the board to the battery negative on the extension cable for my battery. So let's say I changed all 12 mosfets would that fix the problem or would I have to find what the problem was in the first place before I change them because they might get shorted again? It looks like some of the mosfets actually have a crack in their leg maybe they're not fully connected on the one leg there's three legs on each and about 6 out of 12 them look like they have cracks in the solder but no signs of burning or anything and the rest of the board looks okay except for one capacitor that is not swollen but it looks like it's caving in a little tiny bit. When capacitors go bad is it possible for them to cave in instead of pop up swollen? Thank you in advance for your time!!!

[@antorchabikes]

Hi, excelent video thanks a lot. i have a question. i have a controller that PAS works fine but throttle doesn't. i already tested throttle in another system and works fine. also made this test (fase and + or -) and it is working fine. do you know what more test can i do to the controller?

[@46B3x2you]

There may be two blue wires that connect together and cause the controller to limit your speed to 20 miles an hour. If you disconnect those two blue wires. You will be able to override the 20 mile per hour limit.

[@harryhughes5868]

Hi my girlfriend has an old bateribike which stopped working. we have tried a new battery , no goog we think it is the controler, ? any help would be good. Harry

[@antorchabikes]

@@harryhughes5868 hi it could be several issues. i teach in my channel how to try step by step, sorry it is in spanish! kzbin.info/www/bejne/Y168lHSJmrGphKM

[@tastytechaddictsmtb]

I’ve got zero ohms to positive battery when probing the phases, is this also bad ?. They’re fine to ground, but phases are zero to positive, but only a certain polarity.

[@GrinTechnologies]

Generally yes, this is bad as it would be a short of the high side mosfet

[@tastytechaddictsmtb]

@@GrinTechnologies I’ve taken all mosfets off and they’re fine. If I switch the probes though it goes away.

[@garyosgood7499]

Can anyone please help me with a faulty e scooter? Every time I go to charge it up it shorts out the battery charger. The battery is actually fully charged, I disconnected the battery from the control unit. Every time I go to connect it back up it blows the battery connectors to bits

[@gigicontra2447]

hi,i have a problem with my ebike,battery is draining fast around 10miles range also when i put the battery on the bike it makes sparks at the connectors,i replaced the battery pack with a new one but still doesnt go more than 10miles ,im thinking it has a short but how can i test it

[@jamest.5001]

I just bought a controller, no paper work, but the connections are labeled, I guess! I can't read Chinese!!! Ant idea how to figure this out??? I know the phase and power, and switch wire, but clueless to what the billion other wires are for!! I didn't get what I ordered, but its the same controller, just lower wattage, I need to figure this out, the only thing I need is the throttle, and maybe the brake safety, I was planning to run sensorless , but if not , us there any specific order for the phase wires? Thanks

[@evil17]

Hi, if the motor spins the wrong direction try to swap two phases over, this is how you would reverse a 3 phase motor direction

[@GrinTechnologies]

It's usually straightforward to identify the 3 phase wires, the 5 hall wires, and the 2 battery leads. Identifying which of the other cables is your throttle signal (vs ebrakes, on off switch, lights, horn, etc) usually requires trial and error, but that's not the topic of this video which is simply about identifying and replacing a shorted mosfet.

[@BruceRecord]

Can you shine some light im new to this an have an issue with my e-bike ,thanks

[@gerhardmalberg4966]

Only LOW side mosfets can short to ground when fail and are thereby detected by measuring between GND - DRAIN (body of mosfet) HIGH side mosfets can short to PHASE when fail and are thereby detected by measuring DRAIN (body of mosfet) - PHASE (one of the three phase wires)

[@MKxSylOiZ]

Thanks for this great guide, the biggest problem to find the right china mosfet, in my case it is a brainpower control. DC52V (the scooter is a Speedway 4 clone + no dualtron 1x800w motor) the mosfets(to 220) have the designation: K M ..9Y ....... 19x 2452 ..... L12 .... K3475N .. Unfortunately I could not find a data sheet to find comparable replacement mosfets. does someone have a tip?

[@neenyohpastoral1951]

Have an issue with my controller, once you twist the throttle then let go, the hub motor does not stop running, cruise wire is not connected nor enabled. Any diagnosis on this scenario?

[@GrinTechnologies]

We don't do tech support on KZbin. Could be a throttle issue and a simple swap out... if it's our system please contact our warranty department.

[@trevorjames5493]

When I do continuity from positive to decide which ones are positive and negative I get continuity on all 12 mosfets to battery positive and none beeps on the negative, what's that indicate?

[@bspalteh]

Thanks for putting these videos together, very useful!

[@bobjerome5390]

hi in the uk there are cop in car's that are not marked abd if you go over 15mph in the uk they will not be happy london under cover cop's my brother got told of i for got to set the speed right there are some power crazy cops my uncle was in the cop's the london cap high up

[@marleneboltz4838]

Everything is connected and still the motors are not turning on mine

[@46B3x2you]

thank you so much. Good Job. You just made a horrific challenge into a simple fix.

[@roncooke2188]

I have an ebike just come in been standing in his shed 6 months, has no light on display, battery is good fully charged all wiring and connections are controller connections all good bike is only 18 months old , any pointers please ??? could be controller but all looks new condition

[@christothegreat1]

What if any is the risk to replace only the 2 blown mosfets out of 6, with ones that are quite close in values V, A, Rdson?

[@isaacogedegbe5557]

Hi, awesome video thanks, I use an Hover 1 alpha E scooter so two days ago I was changing the accelerator of the scooter, and in the process of assembling it together i found out that the beeping device was lose but before I could touch it one part it's poles mistakenly touched the pole of the display panel which resulted in some weird noise and the break light blinking and unfortunately the Scooter went off and wouldn't come on again not even charge any longer , do you have any idea what could be the issue Thanks..

[@GrinTechnologies]

Well it's most likely not a blown controller mosfet ;-)

[@isaacogedegbe5557]

@@GrinTechnologies Wow Thanks for replying really appreciate, So what could it be then :•{

[@Pirelli.]

Great. Thanks! Maybee A stupid question: Does it still make sense to adjust the 2 shunt sensors, i mean by soldering make it wider, bridging. You sure know what I mean. I have an escooter with 2x 45A controllers (1 controller per wheel) and the BMS also offers 90 or 100A. The BMS circuit board on the battery pack can only spend as much as it says, no more?! I hope someone can tell me whether that still makes sense or not. Thank you all 😊

[@GrinTechnologies]

Doing this will increase the battery and phase current limits of the controller, but it will also increase the likelyhood of frying your controller mosfets. If you have a 90A BMS and each controller is 45A battery current limited, then if you went any higher on the controllers you'll trip the BMS overcurrent cutoff when you try to run full power.

[@Pirelli.]

@@GrinTechnologies Thanks

[@viynmobility3121]

My controller has two wires each for the brakes(the brakes are on when i short the wires of one brake) and i want to use one of the brake's wires with relay to control with arduino is this possible ? If not what should i use?

[@jarikinnunen1718]

When you open controller case, you maybe never get it together, because case is mosfets heatsink and brackets fall of inside and isn't any way to get them back, without special tool. I have experience of that.