Send MMM in for repair?

[Thirdgen89GTA]

I've got a car thats decided to start doing funky stuff.

Motor combo is a V3 MMM with a 1717. Power is supplied by a castle external bec, and its setup for 6S using twin 3S packs in series.

On an initial start if I give it fast throttle input the car will Jerk and then the ESC will reset as if it lost power. If the car is already rolling it doesn't do it.

Steps taken to diagnose:

• Tried batteries one at a time, both batteries do it.
• Tried the batteries + series connector with another ESC/Motor system from my 1/7th scale car.
• Checked the ESC battery connector for pitting or a bad solder joint.
• Looked for wiring breaks to the BEC.
• Lowered start power value in ESC to "Lowest".

Only things left to check are to try an external receiver pack to supply power, and install the other 1717 into the car.

I don't think its a motor issue, I'm thinking more on the ESC, or with the BEC.

Thoughts?

[bdebde]

try a different firmware? I have seen similar problems on older MMM's with newer firmware. If you updated the firmware, put the old version back on it.

[Thirdgen89GTA]

Firmware 1.32, never changed it from the factory. Its the last stable release and I don't feel like trying out the betas.

[whitrzac]

Turn off auto lipo cut.

It could be crappy batteries/solder joint.

[Thirdgen89GTA]

Originally Posted by whitrzac

Turn off auto lipo cut.

It could be crappy batteries/solder joint.

Batteries and Series connector work fine in every other vehicle. Including a 1/7th scale on-road that is 11lbs and exceeds 100mph. Aka, it was a Traxxas XO-1 before Traxxas made the XO-1.

The batteries may not be the freshest daisies anymore, but they certainly aren't the cause of the issue on one specific RC. If they were, it would follow the batteries, or it would follow the series connector.

[phildogg]

Funny i just had the same thing happen to a mamba xl esc. I tried everything, even a motor with no load if given throttle to fast loses power. I tried different batteries, i tried a receiver pack (took out red wire). different motor. Finally gave up and sent it back to castle today. weird i just read this.

Edit: I had to change the lipo cutoff or it wouldn't recognize anything other than a 2s lipo. All batteries are in good shape and work in all other vehichles.

[phildogg]

Called today and talked to a castle tech( brian i think). he acted like the esc couldn't be at fault. even though i explained all i had went through checking everything, receiver, batteries, motor. then he said my hitec 645 was pulling too much current for a 1/5 scale esc.. wheres patrick at when we need him?