Mini-Z, Kyosho Mini-Z Racer, MR-03, MR-02, MA-010, Forums, News, Pictures, Parts, and Shop - Mini-ZRacer.com
Forums, Mini-Z, MiniZ, Kyosho Mini-Z, Kyosho MiniZ, Kyosho Mini-Z Racer
Mini-Z Hop-Ups, Mini-Z Parts, MiniZ Hop-Ups, MiniZ Parts, Kyosho Mini-Z Hop-Ups, Kyosho Mini-Z Parts, Kyosho MiniZ Hop-Ups, Kyosho MiniZ Parts, Kyosho Mini-Z Racer Hop-Ups, Racer Kyosho Mini-Z Parts
Old 2007.03.08, 10:35 PM   #1
kchan
Registered User
 
Join Date: Mar 2007
Location: Ann Arbor
Posts: 4
Help! No Throttle Response, Motor Run Away with Switch Off!

I drove my MA010 tonight. It suddenly stopped responding to throttle input. When I switched it off, the motor went full throttle.

I took the AD board out and found no burnt on the FETs. I don't know why the switch off position can cause some kind of short circuit that drive the motor. If I connect power to the board, it drives the motor when the switch is set to off position. The steering still works though.

I have seen a post regarding a similar issue, but there is no follow-up on it. I did a few searches, but I could not find anyone else who has the same issue. Has someone experienced the same problem and found a fix for it?

Btw, I have a PN Speed AWD stock motor in it and use 2S Lipo battery.

Thanks a lot for your help.
kchan is offline   Reply With Quote
Old 2007.03.08, 10:58 PM   #2
homestar21
is sleepy.
 
Join Date: Dec 2006
Posts: 374
Send a message via AIM to homestar21 Send a message via Yahoo to homestar21
Do you have upgraded FETs? if so, check for a faulty soldering job. If not, it could be the li-pos. But if steering still works, maybe it's the motor.
homestar21 is offline   Reply With Quote
Old 2007.03.08, 11:05 PM   #3
kchan
Registered User
 
Join Date: Mar 2007
Location: Ann Arbor
Posts: 4
Thanks for your reply. I have not upgraded the FET yet. I tried to look for burnt mark or shorting, but I have not found any. The motor should be ok though because it still runs when the car is switched "off". It is just very strange. I thought switching it off would cut power, but it shorts the circuit instead.

I have seen repair service offered by ********** and ******, but I am not sure if they can fix it if the FETs are fine.
kchan is offline   Reply With Quote
Old 2007.03.08, 11:57 PM   #4
homestar21
is sleepy.
 
Join Date: Dec 2006
Posts: 374
Send a message via AIM to homestar21 Send a message via Yahoo to homestar21
the names will not show. anyways, are your li-pos soldered directly to the board, or through a deans plug?
homestar21 is offline   Reply With Quote
Old 2007.03.09, 11:53 AM   #5
svt-racer
Registered User
 
svt-racer's Avatar
 
Join Date: Jan 2007
Location: 2 miles from AA Club Track, MI
Posts: 164
It is my understanding that the switch is more of a ON or standby...not really off. I have been told that there is suppose to be a small amount of power draw even when the switch is flipped to the off side. One way to find out is checking the leads to the switch and check for continuity. If this is the case, your board may be toasted. If not, then your car must be possesed!
__________________
SVT-RACER (aka Schumi)
Ann Arbor Club, MI
MY WEB DOJO
svt-racer is offline   Reply With Quote
Old 2007.03.09, 01:46 PM   #6
CristianTabush
Registered User
 
CristianTabush's Avatar
 
Join Date: Feb 2005
Posts: 1,683
The fets are fried. They don't necessarily have to be visibly damaged to be burnt up. Ad band and lithium don't go very well together.
__________________
Cristian Tabush
REFLEX RACING USA
10 Time Mini-Z World Champions!!!
http://www.reflexracing net
CristianTabush is offline   Reply With Quote
Old 2007.03.09, 03:31 PM   #7
Draconious
Moderator
 
Draconious's Avatar
 
Join Date: Nov 2001
Location: Goodrich MI
Posts: 6,164
Send a message via AIM to Draconious Send a message via Yahoo to Draconious
if u turn off switch and the car starts full throttle... its fried.
__________________
Draconious is offline   Reply With Quote
Old 2007.03.09, 04:57 PM   #8
homestar21
is sleepy.
 
Join Date: Dec 2006
Posts: 374
Send a message via AIM to homestar21 Send a message via Yahoo to homestar21
Well, all I can say is I'm sorry for your loss.
homestar21 is offline   Reply With Quote
Old 2007.03.09, 10:45 PM   #9
kchan
Registered User
 
Join Date: Mar 2007
Location: Ann Arbor
Posts: 4
Thanks for advice everybody. At least I know it now it was fried.

If it is fried, what can I do to repair it. I wonder if I can replace the FETs or install an external turbo to bypass the problem.

It is quite expensive to replace the whole AD Board. It costs around $100 for the whole set. An external turbo costs around 50-60 which can solve the lipo-AD Board problem altogether.

Thanks again for your advice.
kchan is offline   Reply With Quote
Old 2007.03.10, 08:06 AM   #10
Draconious
Moderator
 
Draconious's Avatar
 
Join Date: Nov 2001
Location: Goodrich MI
Posts: 6,164
Send a message via AIM to Draconious Send a message via Yahoo to Draconious
Just replace the fets... $1-$3 each... only need 2... you will want to replace them both just incase...
__________________
Draconious is offline   Reply With Quote
Old 2007.03.10, 10:47 AM   #11
homestar21
is sleepy.
 
Join Date: Dec 2006
Posts: 374
Send a message via AIM to homestar21 Send a message via Yahoo to homestar21
yeah, you can get really cheap FETs at some places.
homestar21 is offline   Reply With Quote
Old 2007.03.10, 10:53 AM   #12
kchan
Registered User
 
Join Date: Mar 2007
Location: Ann Arbor
Posts: 4
I am relieved. At least I don't have to replace the board.
Soldering such a small component is challenging to me, but I can send it out for repair at the worst case, which is still way cheaper than getting a replacement board.

Thanks a lot for your advice.
kchan is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Runaway Throttle TITANIUM Parts and Hop-ups 10 2005.03.15 09:43 PM
Throttle Response using FETS Roger Setups 22 2005.01.12 05:35 AM
Throttle sticks... walds11 Beginner Questions 3 2003.06.13 11:47 AM
Mini-Z Switch, protection, Design flaws Draconious Mini-Z Science 5 2003.01.21 01:25 PM
light kit with working brake lights laminaleigh Mini-Z Science 21 2002.12.05 08:48 PM


All times are GMT -5. The time now is 02:04 PM.


Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2011 Mini-ZRacer.com
Mini Inferno Sale - Up to $85 Instant Savings!
Micro-T Hop-Ups
RC18R, M18, Micro RS4, Mini-LST, TamTech-Gear, Minizilla, RC18T, RC18B, RC18MT
shop.tinyrc.com Products

more»
Tiny RC Community News
[03/22/17] MZR was on vacation, didn't... : All kidding aside, the host experienced a bit of a server meltdown last week and efforts to restore the site to a new server took longer than anticipated. The current server is temporary until - more»
[11/25/15] Did You Hear? Our Black... : Hey Racers,
We're getting started a bit early with our Black Friday sale this year.  Generally we're not supporters of retailers opening early on Thanksgiving, but in our case, we're - more»
[06/30/15] shop.tinyrc.com: Have You... : Hey All! Just a quick reminder to everyone that we post all of our shop.tinyrc.com Newletters here on the MZR Forum. If for some reason you miss them in your email inbox, you can always see the - more»
Mini-Z, Mini-Z Racer, MR-02, MA-010
M18, M18T, RC18T, Mini-LST, Mini-T, Micro RS4, XRay, 1/18, 18th scale
XMODS, XMOD, Micro Flight, ZipZaps, ZipZaps SE, Bit Char-G, MicroSizers, TTTT, Plantraco Desktop Rover, SuperSlicks, Digi Q
Mini Inferno, Mini Inferno ST, half EIGHT, 1/16, 16th scale
Epoch, Indoor Racer, 1/43, 43rd scale
E-Savage, eSavage, eZilla, e-Zilla, HPI
Robots, Bots, Bipeds, Wheeled, Manoi, Roomba, NXT, Lego, Hacking
Crawling, Crawlers, Micro, RC, Losi Mini-Rock Crawler, Duratrax Cliff Climber
Kyosho Minium, Caliber 120, Minium Forums
Mini-Z Hop-Ups, Mini-Z Parts, Mini Inferno Hop-Ups, Mini Inferno Parts, M18 Hop-Ups, M18 Parts