View Full Version : No steering ...

2009.02.13, 04:55 PM
I bought a Mini-Z MR02 Racer "i" just a couple of weeks ago, and today it lost its steering ability. I had probably ran it for an hour straight when it just stopped steering. Nudging the front wheels back and forth seemed to solve the problem, and then it worked fine again for a while. Then it stopped working more and more frequently, and now the steering doesn't work at all.

I took the steering "servo" apart, and by giving the motor a little nudge, I can get it running in the right direction and speed. As soon as it stops though, it cannot start again by itself. The motor turns pretty easily, and once it starts running it can go quite fast, so that doesn't seem to be the problem.

It doesn't have anything to do with the transmitter, and the trim pot on the board seem to work fine. I'm lost here, and I didn't think of sending it to Kyosho before I had already taken it apart, so now I'm afraid I might have voided my warranty ...

Any ideas are greatly appreciated!


2009.02.13, 10:23 PM
get some high quality contact cleaner and spray down the POT, also make sure that the POT is align with the bracket properly when you re-assemble it i also put some 10/30 oil on all of the gear pins and on the gears

2009.02.14, 02:08 AM
Make sure that the wires are are all connected properly, and that they are not being pinched by the cover.

2009.02.14, 12:23 PM
Check the steering FET's as they can burn in the same way the power fets do.

2009.02.14, 10:00 PM
I would take the steering motor out of the servo assembly and turn on the car. Careful not to short the wires to the battery. Use some tape to cover connections. Once the car turns on, the motor should spin freely and fast. Try to rotate the pot from one end to the other. Somewhere in the middle, the motor should stop and then rotate in the opposite direction. If you are careful turning the pot, you can even get the motor to stop spinning. Leave the pot alone, and the motor should remain stopped for quite a while. This will test the motor and the pot.
If the motor does not stop for quite a while, then the pot is drifting - clean the pot.
If the motor does not turn, then it is the motor or the FETs. Use volt meter or connect the main motor to check for voltage. Steering FETs should run the main motor just fine since it is the same FET as the main motor. No voltage = FET issue.
If all works fine, then is the servo gears. - Sometimes small object get lodged in the servo gear, and stop the steering. You have to use a x-acto knife to clear out the debri.

2009.02.17, 02:13 AM
Once I had taken the whole thing apart I realized this should be covered by warranty. I put it together, hopefully without messing anything up, and the chassis is now on its way to the store again. I hope it really is covered by warranty, and that I get my car back as soon as possible. I'll probably receive a bunch of sweet PN Racing parts tonight, and I can't wait to install them.

Thanks for your helpful comments!

2009.02.20, 03:19 AM
let us know what happens... looks like everybody covered just about everything here...
pot, wires, servo gears, dirt in the servo gear, blown fet... good luck