Mmx8s problems.. :-/

[Rcproponent]

Hey everyone,

So I was getting my truck out to play today and noticed my fan wasn’t turning on on my esc. (Mmx8s)

Also, I plugged in my new set of hobbystar batteries to it and it only chimed off 7 of the 8 beeps for the cell count.

I thought hmmm that’s weird... maybe a dead cell on one of the new batteries... popped them on the charger... nope all cells good...

??.... no fan... and incorrect chime count for cells... so I plugged in another set of batteries and it counted the cells correctly ... ok cool. Now I go run it a bit to see if getting it warm trips the fans...

Brought the motor up to about 160 degrees and the esc to about 135 degrees and no fan still ??‍ This is not normal right ?

Also, mid run when I was checking everything out I powered down and back up and it was doing the cell count wrong again... chimed 7 times for 2x 4s lipos..

Anyone know if I maybe have a bad esc ??

Thanks for your time...

 

[fpvmiller]

Watching. I just got my usb programmer delivered today but I don't even have battery terminals soldered yet.

 

[jondilly1974]

I would call their support on Monday if you can. Maybe email them if you are unable to call. They were very quick to help me on my MM2 Retro issues.

 

[Overpowerrc]

1+ to Jon

 

[Rcproponent]

I will see if I can find a link for the tech support. Thanks folks!

 

[LibertyMKiii]

Mine has never gave the chimes for cell counts. After a crash one if my fan blades bent up and wedged into the fan cover. I pulled the cover and the fan worked. (6+ runs in the 106 to 119 mph range.)

It runs fine now after fixing the stuck fan. I probably need to contact support though. I am curious to hear what they do for you....

 

[Rcproponent]

Mine has never gave the chimes for cell counts. After a crash one if my fan blades bent up and wedged into the fan cover. I pulled the cover and the fan worked. (6+ runs in the 106 to 119 mph range.)

It runs fine now after fixing the stuck fan. I probably need to contact support though. I am curious to hear what they do for you....

Worth a shot, I will pull the cover and see if the fan works again...

After plugging fresh batteries in again, the cell count, counted proper... the somewhat drained ones are only chiming 1 less than they are supposed to... the must chime to a certain voltage.... thanks for the ideas

 

[jondilly1974]

Mine does the cell count chime. In fact, when my MM2 stopped doing the chime, support was certain that was a bad sign and said send it in.

 

[Rcproponent]

Mine does the cell count chime. In fact, when my MM2 stopped doing the chime, support was certain that was a bad sign and said send it in.

So, let’s say you get done with a 6s battery pack, it’s toast,,, if you turn off and on your esc does it still do 6 chimes or does it do like 5? Currently ... if I start out with 2 full 4s bats.. it will chime 8 times... then when those packs are depleted ... it only chimes 7 times. Maybe it has to do something with the depleted battery! My biggest concern was the fan not working... still have to take the cover off and check that out...

 

[Mr.Duke]

The fan on the Mamba Monster X 8s is thermally controlled. When you first power up the ESC it will do a power on self-test to show you the fan is functional. When the ESC arms the fan will stop running and then only turn on when the ESC reaches 140° F/60° C.

 

[Hammer Down]

I still need to take a closer look at my new MMX8s fan that came in my 1717 combo and see if the “rolling change” they were supposedly making has been implemented yet...?
I know the first batch of fans, like the one that came in my 2028 combo was ?!

 

[jondilly1974]

So, let’s say you get done with a 6s battery pack, it’s toast,,, if you turn off and on your esc does it still do 6 chimes or does it do like 5? Currently ... if I start out with 2 full 4s bats.. it will chime 8 times... then when those packs are depleted ... it only chimes 7 times. Maybe it has to do something with the depleted battery! My biggest concern was the fan not working... still have to take the cover off and check that out...

Can’t tell you that as I honestly usually only do a pass or two on a pack at most. I don’t really draw them down very far or power cycle between passes.

 

[robert@castle]

I still need to take a closer look at my new MMX8s fan that came in my 1717 combo and see if the “rolling change” they were supposedly making has been implemented yet...?
I know the first batch of fans, like the one that came in my 2028 combo was ?!

The rolling change has not been done yet. We got samples of the new injection molded parts and everything looked good so we ordered a few thousand parts. Got them in and most of them are wrong. For now I'd recomend removing the fan cover or spacing it slightly up with some washers.
As stated, the fan should spin up on power up to show it is working and then stay off until the ESC reaches 60-65C.

[to the op]
I'm not sure why those packs would count at 7 cells. If they were fully discharged it might show an 8 cell pack as 7 cells because they 8s voltage dips below what 7s would be fully charged, but I don't think you are plugging in discharged 3.7v/cell batteries.

For anyone not having beeps, it will not cell beep if you have the cutoff set to a specific voltage instead of Auto-Lipo. If you are always running 8s, it might be a good idea to set a voltage rather that relying on the cell beeps because if the ESC resets when the pack is low while running it might see it as a fully charged 7s pack and over-drain your cells.
If you should have beeps, try updating the settings again to make sure they set correctly. Another thing to try would be to update the firmware on the ESC. Sometimes a bit can get changed in the processor and it messes it up. Updating the firmware to the same version you are on can sometimes fix issues that appear "random".

 

[Rcproponent]

The rolling change has not been done yet. We got samples of the new injection molded parts and everything looked good so we ordered a few thousand parts. Got them in and most of them are wrong. For now I'd recomend removing the fan cover or spacing it slightly up with some washers.
As stated, the fan should spin up on power up to show it is working and then stay off until the ESC reaches 60-65C.

[to the op]
I'm not sure why those packs would count at 7 cells. If they were fully discharged it might show an 8 cell pack as 7 cells because they 8s voltage dips below what 7s would be fully charged, but I don't think you are plugging in discharged 3.7v/cell batteries.

For anyone not having beeps, it will not cell beep if you have the cutoff set to a specific voltage instead of Auto-Lipo. If you are always running 8s, it might be a good idea to set a voltage rather that relying on the cell beeps because if the ESC resets when the pack is low while running it might see it as a fully charged 7s pack and over-drain your cells.
If you should have beeps, try updating the settings again to make sure they set correctly. Another thing to try would be to update the firmware on the ESC. Sometimes a bit can get changed in the processor and it messes it up. Updating the firmware to the same version you are on can sometimes fix issues that appear "random".

Thank you again for the reply Robert. I will space my shroud with washers. I will also try and update the settings and see if this changes. Thank your for your attentiveness.!

Much appreciated.

 

[jondilly1974]

Just received my replacement MMX8S in the mail today for the defective MM2R that I sent back last month. Hope to put some ends on it in the morning and give it a rip ????

 

[Rcproponent]

Just received my replacement MMX8S in the mail today for the defective MM2R that I sent back last month. Hope to put some ends on it in the morning and give it a rip ????

Robert has a good point, put washers under the fan cover and you should be golden. It’s very close tolerance in there... the first blade of grass that the fan picks up will lift a fan blade and get it wedged like mine was. Split my fan blade too. This was my solution..

Power hobby high volume fan. It lifted the cover and now there’s more airflow ??