Brushless help!!

[benl]

Hello Chaps,
I recentley became the rather proud and excited owner of a second hand B4 complete with an LRP SPX stock spec and LRP X11 8.5 stock motor .
I was hoping to have my first day of racing tommorrow (actually later today:drool:) at TORCH.
Everything was running fine until this afternoon a quick test blast on the track outside my house and eveything ground to a halt.
The Motor only spins up occasionally now. It seems I have to manually turn the rotor to the right position to get it to engage which then works but stops as soon as I apply the brake or lift off the throttle.
I have checked the speed controller and all the lights are good etc.
I dissmantled the Motor and the rotor seems fine. Sensor wire looks ok etc.

Anyone got any ideas, any help at all would be appreciated :)
Thanks
Ben

[sosidge]

It does sound a lot like sensor issues. I would try swapping the cable for another one, even if the original looks OK.

Apart from that, I would double check that you are on the correct ESC settings for that kind of motor (not one of the Stock settings with advanced timing), and I'd also double check that one of the windings in the motor hasn't burnt out or failed.

[benl]

Hello mate thanks for the reply:)

Ive tried with a known good lead and also on all power modes 1 through 8,

I think you may be right in that its one of the windings, any idea how to

test them ?

Thanks again

Ben

[benl]

On further inspection it looks like one of the windings is kaput.
Not sure how this has happend. Dosn't really look repairable so think I am in the market for a new motor :(
Thanks for your help though.
Ben

[adey]

I had the exact same issue with my nosram stock spec and team powers 10.5. I believe the nosram is the same as the Lrp and it turned to be the esc. I stripped my esc and split the boards to find a chip he'd burned out.

[benl]

Do you know which chip it was burned out? Were you able to repair it?
Thanks
Ben

Quick Edit:

Just tested the SPX speed controller on an old brushed motor (from my sons Grasshoper shh dont tell him) and its working fine on that.

[martgifford]

I think I have exactly the same problem. What I believe the cause is the sensor board on the motor. It stops on the same spot and needs to go to the next rotation to start. Now the reason it's not the sensor wire is I tested it with a core RC sensor tester. Now it appears you can replace the sensor board on the motor for part 50623. Rrp 10.99. I am startIng to wonder about Lrp motors. My speed passion has been run a lot hotter and more and never a problem compared to Lrp

[benl]

I think you may be right I de-soldered my sensor board and am currently openng up old eletrical items i have to look for some surface mount capaitors to replace those on the board, although I think it may be a problem on the board itself.
Thanks for the pt number although I have an X11 which has a different board which I dont think is aailable anymore. :)

Ben

[benl]

Ok it wasnt the motor
Tried a replement motor an still the same,
so I took the plunge and opened up th SPX speed controller.

One whole row of fets looks blown :(
anyone know where I an getsome 4833N 909 fets from?