View Full Version : everything works, except going forward!

2013.01.25, 04:59 PM

I currently have 2x MR-01 chassis (since 2003) that I race against MR-02(EX) and MR-03 cars. I am quite pleased with the performance i get from my old cars. Yesterday though, one of them started behaving strangly :
I got some hiccups and afterwards I couldn't move forward! I'm still able to steer and back up the car. When I adjusted the throttle trim to forward it still went forward, but not with the transmitter... I tried using a different transmitter and changing crystals but got no response. I came home tonight took it apart to see if I had some loose wires and put it back together but without any luck. I still can't move forward with the transmitter and now I can't even get it moving by adjusting the throttle trim!

What could it be? Should I start looking for a different board?
I would really like to fix this problem. only a few days ago it performed flawlessly and I won round after round against the boys with their MR-02 and MR03 cars :-)


Thanks already,

2013.01.25, 08:29 PM
greetings and welcome to the forums. a couple of questions first tho… what motor are you using? what pinion are you using? have you used your controller in another car? if it works on a diff car, my guess is that your fets are fried (take a look at the boards, sometimes fried fets have a bubble in them)… have them replaced and you're good to go… go to your local track and ask around, there are also some guys on the forums that offer fet upgrading services… it's nice to hear that somebody is still using the mr01… hope this helps good luck

2013.01.25, 08:36 PM
1. Examine fets
2. Examine motor for brushes to commutator contact
3. Maybe check the tx contact on the throttle position. It's rare but worn transmitter contacts could be possible.

2013.01.28, 05:19 AM
I'm using the Atomic AR076 Standard Motor on both cars. pinion is usually 7T or 8T.
The controller has been used on different cars, without problems. I'm already looking for a replacement board since I don't know anybody in Belgium that does FET repair.

Can you tell me what type of FETs I should use to repair it with?

Thanks for the info.

2013.01.28, 05:48 AM

I'm from Belgium, where are you from?
The nearest place you coul dget your board fetted would be orange RC in france. I had a board done there recently, in fact I still need to get it back :)

2013.01.28, 06:45 AM
I live near Brussels, but I work near Antwerp.
Do they just add FETs or do they also replace them?


2013.01.28, 07:10 AM


2013.02.05, 05:07 AM
Thanks, I will check them out.
In the meanwhile I've bought a MR-02EX converted to MR-03 chassis and a new MR-03.
It looks like my alu RM and HM motormounts fit the MR-03 chassis :-)