Repairing / Fixing a Milwaukee M12 Multitool (M12-FMT)

In this video I'm repairing a Milwaukee M12 Multitool (M12-FMT).
The tool has the following symptoms:
1)Lights that either flash in an alternating pattern or it thinks that the battery is flat and flashes only one LED when a fully charged battery is inserted.
2)The motor does not spin.
So.. let's fix it!

[@user-te1le7ck6b]

Great work yet again pal , you must have saved a fortune of course minus your time , well done and keep them coming

[@BuyitFixit]

Thank you!

[@599miata]

Excellent repairs, mate. It even plays and makes music...😂😂

[@BuyitFixit]

😂😂😂😂Thanks 👍

[@ColinTimmins]

Found your channel by reading your comment on Big Clive’s channel and thought I’d subscribe considering we have similar interests. =]

[@BuyitFixit]

Thank you! Got a few more milwaukee repairs and other stuff in the pipeline!

[@waynetaylor2784]

The goop is called epoxy potting, or silicone potting (rubber) heat, acetone or nitric acid too break it down. Or OCA/ LOCA remover. (Liquid/Optical Clear Adhesive) it's used on mobile phone screens

[@BuyitFixit]

Thanks. I was using heat on some other boards and have some acetone. So might give it another try.

[@thetraindriver01]

Great fix, it would be great if you could film the oscilloscope part for the frequencies you are getting that look wrong and maybe a what's in my workshop tour? hopefully on another new video 🙏👌👏

[@BuyitFixit]

Thanks, at the time of making this one I don't think I was set up for multiple cameras or even knew how to do multiple cameras in the video editing software.. I am getting better at it 😂😂

[@generaldisarray]

Fantastic fix, yet again. Well done sir. I thought you were going to play the star spangled banner there at 13:54 when you were doing the speed test... 🤣🤣 It would actually make for a good instrument for some sort of power tool band.

[@BuyitFixit]

Thanks👍.. musical instrument 😂😂

[@generaldisarray]

@@BuyitFixit It kinda sounds like an electric Kazoo...🤣🤣

[@daviequecushnie4957]

And grate job on that multi tool

[@BuyitFixit]

Thanks Davieque👍

[@dadwillfixit1907]

Great fix 👍🏻👏🏻

[@BuyitFixit]

Thank you kindly sir.

[@nesertema4583]

amazing detective work and skills! I only watch because I have a couple of milwaukee tools, all working fine, just curious what all can go wrong with tem 🙂

[@BuyitFixit]

Thanks I've got a fair collection now. I'll fixed quite a few different tools, and I've got some other tools to look at soon 👍

[@billyharrison3734]

I've got one of these and it needs fixed, I also live in Newcastle if you're interested in the job

[@ianhelsbyservices]

Packs of ten for those chips on Aliexpress and not unreasonbly price. Likely Milwaukee will use the same or similar chip in other M12 units. They feel solidily built. I'm left wondering if there was some kind of surge that blew the ground pin on the chip but the processor is OK.

[@BuyitFixit]

I think the motor controller failed then blew the track, although the original chip wasn't getting hot or anything but it was giving weird output waveforms. I was a bit worried about the 10 packs from Aliexpress because I've had fake chips from that site before when fixing the Samsung washing machine about 3 years ago.

[@ianhelsbyservices]

@@BuyitFixit could we get a shot of probing the chip for waveforms on your next encounter with a view of the oscilloscope. That's a tool I need to acquire at some point

[@BuyitFixit]

@@ianhelsbyservices yes. I need to either work out if my scope saves video or just stills or set up another camera. That's why it didn't make the final edit as I didn't have another camera set up. I'll try to get stuff like that in shot next time I have a repair that requires it.

[@BuyitFixit]

@@rayvalen249 Hi Ray. You can see the old and new chip with the numbers on the video at 12:10. It's a A4915METTR-T from Allegro MicroSystems. Hope that helps.

[@adl2005]

Did you put the controller chip on with a hot air gun?

[@BuyitFixit]

Yes mate, hot air rework station.

[@daviequecushnie4957]

I have a makita xph07 hammer drill that don't work do u think u could fix it the mosfet got burn on it

[@mikoajburzynski6651]

Hi. A new microcontroller doesn't need a program? Just buy and solder? I have a Milwaukee fms305 and I suspect a damaged microcontroller because the mosfets are ok. Regards

[@BuyitFixit]

Sorry but microcontrollers come unprogrammed. They are basically a computer on a chip that you can program to do whatever you like. If you bought one and just soldered it in. It would not know how to control the rest of the circuit. The pins can be programmed for input or output.

[@user-qm9on1dn6b]

Hey how would you no what to program the microcontroller too? Thanks

[@procrastinator1842]

The 4 lights flashing is what mine does when it cuts out on overload.

[@BuyitFixit]

Thanks for that👍. I think it's just an error indicator that the motor isn't turning or 'something went wrong'

[@procrastinator1842]

@@BuyitFixit I'd imagine a shorted mosfet could also do something similar?

[@BuyitFixit]

@@procrastinator1842 yep, although om this one it was the motor driver chip that controls the mosfets that had failed.

[@procrastinator1842]

@Buy it Fix it yeah I saw that. Just not sure how the brain box knows that the driver has sharted...

[@smallbustboy]

My girlfriend has one of these, she keeps it in her handbag, i have no idea what she would want it for.

[@BuyitFixit]

😂😂😂😂

[@tylerletts8978]

Hi mate my multitool turns on for a split second then cuts off when u insert the battery. What could this be?

[@BuyitFixit]

What do the battery indicator lights do? Do they flash in any type of pattern?

[@waynetaylor2784]

Damned if I can find those controller chips anywhere do you have link to aliexpress? Thanks Wayne

[@BuyitFixit]

Hi Wayne, hope this helps.. www.aliexpress.com/item/1005001790711274.html

[@Kaburn2000_YT]

I have the m18 die grinder, with a dodgy on off switch, sometimes works sometimes doesn't would this vid be same sort of fix?

[@BuyitFixit]

Hard to say as I think they do brushed and brushless versions. Really hard to diagnose something without seeing it or more information.

[@Kaburn2000_YT]

@@BuyitFixit it's the MILWAUKEE M18 FDG-0 FUEL 18V LI-ION REDLITHIUM BRUSHLESS CORDLESS DIE GRINDER, best way I can describe it is you can flick it on and off a dozen times and it won't work but if you twist the chuck end then try turning it on it will usually fire up, it's quite bizarre

[@BuyitFixit]

@@Kaburn2000_YT it could possibly be one of the mosfets blown (the 6 chip type things you see me test near the start) if one had gone open circuit it may still run but not quite right. And you may need to turn it manually to start as you say.

[@BuyitFixit]

It would be like a 3 cylinder running on 2 cylinders

[@Kaburn2000_YT]

@@BuyitFixit I'm with you, I'll have to take it apart and have a look, thanks

[@mikoajburzynski6651]

Could I have your email please

[@BuyitFixit]

It's in the contact page on KZbin

[@mikoajburzynski6651]

@@BuyitFixit Unfortunately, I can't see your contact

[@BuyitFixit]

@@mikoajburzynski6651 it's on the main channel page next to the community tab but I'll post it here too. [e-mail]