Replace battery wires on EzRun Max8

[rflx]

Alright, i'm not proud i have to ask this, but i cannot figure it out and googling didn't yield results:

What is the recommended way for replacing the wires going from my ESC (Hobbywing EZRUN MAX8) to the battery? the wires just dissapear into the case of the ESC and I don't know how to open it up.
My truck has started to just shut down after impact. I suspect a loose connection causes power to be cut for a short moment in those situations. I resoldered the ESC/Motor wires and the EC5 connector on the ESC/Battery wires. How probable is it that the the ESC-side of the battery wires is it fault?

Cheers

 

[Overpowerrc]

Buy a new esc. They are water proof and who ever cut that Close to the esc is not the smartest....?

 

[Ari33]

Alright, i'm not proud i have to ask this, but i cannot figure it out and googling didn't yield results:

What is the recommended way for replacing the wires going from my ESC (Hobbywing EZRUN MAX8) to the battery? the wires just dissapear into the case of the ESC and I don't know how to open it up.
My truck has started to just shut down after impact. I suspect a loose connection causes power to be cut for a short moment in those situations. I resoldered the ESC/Motor wires and the EC5 connector on the ESC/Battery wires. How probable is it that the the ESC-side of the battery wires is it fault?

Cheers

You think you have a dry joint on the power wires going into the esc?
If that was the case I'd expect to see a lot of heat build up on the power wires/connectors from the increased resistance.
I reckon its probably more likely to be in the bullets themselves. I have had similar experience where the bullets inside the connectors become a bit less tight over time.. and start causing issues. I simply prised the males open to give a tighter fit/better connection and that solved it for me.
Might not be that but its worth trying first..

 

[rflx]

You think you have a dry joint on the power wires going into the esc?
If that was the case I'd expect to see a lot of heat build up on the power wires/connectors from the increased resistance.
I reckon its probably more likely to be in the bullets themselves. I have had similar experience where the bullets inside the connectors become a bit less tight over time.. and start causing issues. I simply prised the males open to give a tighter fit/better connection and that solved it for me.
Might not be that but its worth trying first..

Thanks for the tip. I soldered new plugs yesterday and now the ESC won't turn on at all ?
I'm going to whip out the trusty multimeter and see if a can figure anything out.

Sounds like there is no way to open these up?

 

[Mongoose]

I could be wrong but I believe those are soldered to the board and then covered with a waterproofing epoxy. Even if you were able to remove the wires I don’t know that you could completely remove the epoxy to resolder.

 

[rflx]

I could be wrong but I believe those are soldered to the board and then covered with a waterproofing epoxy. Even if you were able to remove the wires I don’t know that you could completely remove the epoxy to resolder.

Oof, alright, thanks. But that makes it sound pretty unlikely that they have come loose. Hope i can investigate further this evening.

 

[Mongoose]

Oof, alright, thanks. But that makes it sound pretty unlikely that they have come loose. Hope i can investigate further this evening.

I’m going to call @olds97_lss in here because I’m pretty sure he has messed with this stuff.

 

[Ari33]

Thanks for the tip. I soldered new plugs yesterday and now the ESC won't turn on at all ?
I'm going to whip out the trusty multimeter and see if a can figure anything out.

Sounds like there is no way to open these up?

Are there no screws on the bottom of the esc.. maybe beneath a sticker?
You might still be able to check the resistance of the solder joints if you could open it despite the epoxy.. not sure though

You would typically set your meter to Ohm x1K (1000) unless it autoranges.

Touch your negitive and postive meter terminals together, you should get a reading of zero. If you don't get zero you need to zero out your meter if it is analog (with a needle). Digitals usually zero them selves out..at least my Brymen, Extech and Fluke meters do.
Zero shows there is no resistantance to the small amount of current running through the terminals.

Touch the positive lead to some part of the wire before the solder joint. I usually push the sharp end through the insulation to the wire to make contact.

Then touch the negitive terminal to the end of the post of the connector on the other side of the solder joint. If there is no resistance your meter should read zero. If it says anything other than zero (i.e. 1, 2,3,etc...) you have resistance and will indicate a bad joint.


Its begining to sound like a fatality with it being totally dead it would usually take open circuit for that rather than a poor solder joint with high resistance.. and if its encased in epoxy its not going to be easy to open it without damaging it further.. but I always like to open them up and try to diagnose what has failed, its an opportunity to learn what happened if nothing else.

Good luck.

 

[Overpowerrc]

To take it off it’ll be taking the simple four screw off by the fan

 

[rflx]

Very nice of you guys to take all the time to explain and take photos, much appreciated!
I removed the top and when I reconnected a lipo, the ESC turned on again. It looks like the issue are the wires to the on/off button. As soon as I move those slightly, the ESC shuts down.
There is four more 1.5mm hex screws, but everything is covered in epoxy and I don't think I can get them loose like that.
I will start molesting the ESC with acetone and see if that can dissolve the stuff. Probably has to wait until tomorrow, though.

Thanks again for the interest and assistance!

 

[olds97_lss]

I figured it was potted like the MXL-6S I had die on me inexplicably. I thought something similar as it went from working to not working almost instantly with no real middle ground, no smoke, no smell, no high temp, just stopped... Since mine wasn't working at all, I decided to try to open it up to see if the solder joint may have cracked, but, like yours, it was completely potted into the case itself. Since it didn't work anyway, I decided to just pry at it with a small screwdriver to peal the case away. Then I used a dremel to grind away some of the potting material near the two main leads.

Still no clue why it stopped working, but the solder joint seemed fine. While plugged in, a chip on the bottom of the esc ran pretty warm that I was able to feel with the case off it, for all I know that was normal.

I guess if you were really really sure that was the issue, you could fix it to a point, but odds are, you would end up destroying the case it's in and you would have to very carefully cut/grind away the epoxy they use around the wires to remove them and resolder new ones on. Worse case scenario is you start with something that doesn't work and end with something that doesn't work.

 

[rflx]

Maybe I just submerge the whole thing in acetone?

I figured it was potted like the MXL-6S I had die on me inexplicably. I thought something similar as it went from working to not working almost instantly with no real middle ground, no smoke, no smell, no high temp, just stopped... Since mine wasn't working at all, I decided to try to open it up to see if the solder joint may have cracked, but, like yours, it was completely potted into the case itself. Since it didn't work anyway, I decided to just pry at it with a small screwdriver to peal the case away. Then I used a dremel to grind away some of the potting material near the two main leads.

Still no clue why it stopped working, but the solder joint seemed fine. While plugged in, a chip on the bottom of the esc ran pretty warm that I was able to feel with the case off it, for all I know that was normal.

I guess if you were really really sure that was the issue, you could fix it to a point, but odds are, you would end up destroying the case it's in and you would have to very carefully cut/grind away the epoxy they use around the wires to remove them and resolder new ones on. Worse case scenario is you start with something that doesn't work and end with something that doesn't work.

You are absolutely right. Not much to loose in this case I guess. I went ahead and submerged the whole mf in acetone. Hope that can dissolve the epoxy.

 

[olds97_lss]

Depends on what the potting is made out of. Not sure acetone has any effect on many types of plastic, only certain types. I can't imagine it's good for the cement holding the heat sink on or the capacitors, those aren't "sealed" I don't think... maybe they are.

 

[rflx]

Depends on what the potting is made out of. Not sure acetone has any effect on many types of plastic, only certain types. I can't imagine it's good for the cement holding the heat sink on or the capacitors, those aren't "sealed" I don't think... maybe they are.

I thought it was epoxy? Acetone usually works well on that. Didn't know there was any cement involved.

 

[Ari33]

Does acetone work on cured epoxy? I thought it only worked on epoxy that hadn't fully set.

Think you need sulphuric acid for cured epoxy... which would probably disolve most things on the board.. :/

 

[olds97_lss]

I thought it was epoxy? Acetone usually works well on that. Didn't know there was any cement involved.

Well, I'm assuming there's some sort of thermal transfer cement holding the esc heat sink on.

I've never messed with epoxy much, other than jbweld. Never tried acetone on it to see what it does.

 

[rflx]

Well, I think it is safe to say that the acetone worked. I can use my fingers to break the epoxy off. The whole ESC now looks a little rough, though ? I think the plastic they used was not acetone-proof.

This feels like kind of a reverse build thread now. So I will post an update when I continue working on it. It will probably take a few days.

 

[Overpowerrc]

Well, I think it is safe to say that the acetone worked. I can use my fingers to break the epoxy off. The whole ESC now looks a little rough, though ? I think the plastic they used was not acetone-proof.

This feels like kind of a reverse build thread now. So I will post an update when I continue working on it. It will probably take a few days.

Still water proof tho eh?

 

[rflx]

Still water proof tho eh?

I ordered a (second hand) quickrun ESC just in case ? Can't have both RCs broken down at the same time for this long, withdrawal is getting serious.

Still hope I can revive the Ezrun though.

 

[RCbuzz]

I has been over 2 years, got an update? Curious to see how this dissection went!