Unity won't turn on

DIY Builds
#43

I was just 500m into a badass mtb track when my Unity took a shit on me. I didn’t get full brake lock though. It just started coasting. The momentary switch light was flashing regularly, then it cut out for good. I can’t find any reports of this flashing switch-light anywhere.

Power supply is verified and so is the momentary switch: continuity on all four cables and the switch closes and opens ok. R103 looks fine. I can’t see any obvious blow-outs on the pcb. Roll-to-start isn’t working. It’s an orange rubbery brick.

Is it worth me getting someone to take a look at fixing it? @seaborder

@Bavioze - yeh, needsies :slight_smile:

Could’ve been worse though. It was a 20k mtb track! :joy:

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#44

@MartinSp do you have any idea of this error?

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#45

Have you measured resistance between GND and 3.3V as well as GND and 5V? If not, please do so with no power input or remote etc connected.
If a VESC does not turn on any LED (especially the blue one) there is a short on some power line or there is no power getting to the DRV/LDO regulator.

EDIT: I see you have some parts of it removed already.
Id honestly be interested in taking a look at it. As a challenge. :thinking:
@brown5tick @Anubis

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#46

I think on mine the MCU is removed, if you can repair it i’ll pay for all the stuff you use on it but I think its ded af

#47

Is mine still good :woozy_face:

20201108_164729
20201108_1647292268×4032 1.91 MB

#48

I’m measuring 876 ohms between GND & 5V and 822 ohms between GND & 3.3V (with nothing else connected).

…and now I notice this:

IMG_20201120_200653
IMG_20201120_2006532368×5120 1.89 MB

I spotted it because of a sooty discolouration on the rubber cover. Anyone know what that is?

3 Likes
#49

ded

2 Likes
#50

eyes_x
eyes_x792×612 28.6 KB

#51

that is LM5060 " the anti spark chip" , common issue with the unity this blows up :slight_smile:

should be an easy fix

2 Likes
#52

As @seaborder says, that is the chip that controls the switch. You can either replace it and have the switch work as intended or bridge the switch mosfets and use it without it.

4 Likes
#53

This is starting to sound quite encouraging.

Is it a flaw with the general design of the Unity or of that particular component? Can the LM5060 be replaced by something more robust, for example, or would replacing it just restart the clock on its inevitable demise?

#54

First component is an led try replacing the second

#55

no not that I know, there are indeed parts that fit on the same pad and work, for example there is a IMU/MPU from bosch (Gyrochip) they changed the design but the pad is kind of the same. I think that was IMU9250.

For the LM5060 I dont think there is something else, the stuff arround is designed to work with it. Like @MartinSp said you could bridge the fet and use an external switch. :slight_smile:

1 Like