MM cuts out! Ideas?

Hello,

Argh! My MM has been running great in my truggy for the past year and now with one week to go before the big RC Monster Bash, it flakes out on me!

Here is the deal, I race it weekly at a small track. Last week, during one of the qualify rounds, I landed a double and there was no power. I think I had steering but there was no throttle. It coasted a bit, then stopped, then a few seconds later, it was back to normal. I ran the rest of the round and ended up winning the main.

This weekend, same kind of thing, only it happens during the main while I'm leading and I end up coming in 3rd. I'm pretty sure I had steering but I'm not positive. The whole event lasted about 15 seconds.

I don't know what to do! It always seems to happen when landing a jump. It actually happened to me several months ago during a practice session. I opened the MM up and blew the dust out of it and never had the problem again till last week.

My plan is to rewire the whole thing. I really don't want to do this as I hate to solder those wires onto the little circuit board of the MM but I don't know what else to do. One of the guys at the track suggested I remove the on/off switch. He said it seemed exactly like the switch went to off for a second and then it was unable to calibrate because I was on-throttle.

What do you wizards think?

Please advise, any suggestions would be appreciated - I'd hate to have this problem next weekend at the Bash, I will have one day to test it out as I will be doing some club racing on Saturday.

Thanks guys!

[BrianG]

Sounds like a flaky solder connection, or a cracked PCB. If it's a solder issue, resoldering will fix it. If it's a cracked PCB, time to call Castle.

Ug...

Is there any possibility to the flakey on/off switch idea? I have a feeling no matter what I should resolder but I'm wondering if I should circumvent the on/off switch while I'm at it?

Thanks for your help.

[BrianG]

The switch is definitely a possibility; I don't usually think of that because I either replace it with a toggle type or simply solder the wires together. It certainly won't hurt, as long as it doesn't void the warranty.

[lincpimp]

If you just remove the switch and solder the wires together the warranty should be fine. If you fool with the pcb the warranty is usually voided. I would check the switch as it sounds similar to the problem I had and the switch was the culprit. A better toggle switch would be a great idea.

Thanks, I'll cut the wires a few inches from the PCB and solder them together.

But I'm also going to redo the BEC, Power and Motor leads just to be safe. I posted photos of the Barn layout as of today in the Bash thread and having a good jumper is going to be key as there are a few MONSTER size jumps!

[MetalMan]

Some local guys have had problems with the MM's switch acting up like that. Can't say I've experienced it first-hand, because I promptly remove all switches.

My resolder job is almost done, I did not find anything bad or loose or broken. I'm hoping it was the switch (which is now perma-on) but for good measure I've got new connectors for the battery and motor as well as removing two deans which were used to extend the power cable and to run a feed to the BEC (which is now hard-wired with no deans.) I hope this does the trick!

did it do the trick? Same thing happened to me a bunch of times. A couple of times is was the switch, once or twice it was bad solder between the motor and esc, once it was the external BEC, and the last time it was actually the wire in the series connected was bad.

I think it's all set now.

Time will tell. I went a lot deeper than I thought. I replaced most of the wires including wires for the BEC, power, motor, heck even my voltage sensor for my Nomadio and re-shrunk the wires on my AMB. I opened and cleaned the BEC, Rx, ESC and made it all the right length for my truck. I took it out for a dirt road test. Beat it as hard as I could and it didn't miss a tick. Then I setup a poorly made (on purpose) jump and crashed the truck twice off the jump at full speed into the grass...it kept coming back and both of those spills were way worse than any that I had at the track this week. I ended up breaking my front bumper but it was still running when I flipped it over.

I'll have some confidence if I can make it all day on Saturday without a blip. From there it's off to the Barn Sunday for the RC-Monster Bash...Fingers (but NOT wires) crossed!

I had this happening on mine to but it was nothing to do with the ESC my CCbec was crapping out on me so I tossed it aside reconected my red center wire and problem solved a new bec was all that I reqired hopefully yours is that simple.