Bookmark Us
Fast Pace Racing
2050 Concourse Drive
Suite 34-36
San Jose, CA 95131
408-943-8283
OPEN
Mon : Thur : Fri
11 am - 9 pm
Saturday: 11 am - 8 pm
Sunday: 12 pm - 7 pm
CLOSED
Tue & Wed
Search
MR03 STEERING AND THROTTLE GLITCH
MR03 STEERING AND THROTTLE GLITCH
First off, Fast Pace Racing would like to thank Doug Graham of PN Racing, an active local driver, for helping us find root cause of the infamous glitch and his willingness to share this in our Mini-Z community. Thanks Doug!
As some of you know, a few of us Kyosho Mini-Z MR03 owners are suffering from the “AM” syndrome – also known as the “MR03 glitch”. This glitch is very inconsistent; it comes and goes whenever it wants to. This made it a bit harder to troubleshoot.
Some owners have their car running perfectly fine with or without modifying anything on the car or the board. Then we get those guys who did nothing but screw in their new damper system or even open the board cover, then the car will start to act weird (inconsistent-glitch), especially on-throttle.
Here is the world first breakdown of what happens, brought to you by Fast Pace Racing!
If you look closely on the board, you’ll notice the two white wires (switch), red wire (power) and the diode (C106):
FYI: this is a brand new board that came from Kyosho (2nd batch).
Notice anything odd about this board’s layout? Nothing obvious, really… However, taking a closer look we notice that the white wire is exposed and is almost (if not already) touching the board. Did I mention installing a new damper system causing the glitch? ;)
…is it the board or the diodes leg? How about, the traces on the board? Hmm…
In the photo above, you can see how re-installing the board-cover can cause the glitch that didn’t exist prior to opening the cover. It is possible that the red wire being pushed down by the cover (perhaps from repositioning the wires) and pressing on the other white wire which is now inconsistently touching the board/trace/leg while vibrating on-throttle or when hitting the bumps on the track.
Here’s another view:
While others suffer only when they open the cover or any type of modification, a few racers are already suffering off the package without even replacing anything on the car! Here’s why: When Kyosho assembly line soldered the wires on the board, a few of these wires are actually stripped too far out and when heat is applied for the solder to melt on to the wire, the insulation being thin tends to pull back which exposes more wire. At this point, the wire is now very close to touching the leg on that C106 diode or traces on that board. How do we fix this?
I am not an expert when it comes to soldering but this can be done very easily. All you need is a fine/sharp soldering tip like Weller’s ST5 or ST7.
First, unsolder the white and red wire. You must place some type of indication on which white wire goes to which tab as you might end up reversing your power switch.
This is where you want to cut the wire.
Then solder the wire back on, standing upward.
Also notice how I solder my motor wire. It is also soldered upright. Please ignore the burn mark on the chassis. LOL Did I mention, I’m no expert at this? J
You want to make sure that there is no excess solder that will contact with other traces on the board or that will bridge to the negative wire. This is how you want your wires to look.
And you should be set!
This is not a guaranteed fix for the MR03 glitch however, it did fix ours.
*Please attempt at your OWN risk. Fast Pace Racing will not be liable for damages that this fix may incurr. You have been warned. 
Thank you for reading.
-Tj Macabuhay
Fast Pace Racing :: Copyright (c) 2009 All pictures are sole property of Fast Pace Racing and may not be re-used without permission.
