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View Full Version : Random shutting off while driving


Sammich
2014.09.02, 08:48 AM
I'm curious. Has anyone have had issues w/ their 03 just shutting off while running? I'm only running a 50T on with a fetted board. Like the entire car dies, i have no steering, motor and the light is off. But if I tap it, or drop it on the layout, or when it cuts off and rolls into the wall, it'll come back to life.

Seems like the motor wires are solid. I have not pulled the top plate off to look at the other wires to the board, which i plan to do this week. I was just wondering if this is a issue anyone else has had issues with before.

Thanks in advance

mleemor60
2014.09.02, 09:00 AM
B. It certainly must be a loose connection somewhere other than the motor connection since you say that you lose everything. First place I would check is where the board connects to the main chassis on either side or the rear bulkhead. Those little tiny screws can sometimes get loose from heat transfer. Especially with fetted boards and bigger motors with too much pinion. After that it's time to go diving.

If you don't get it figured out just bring it with you on the 13th. We will make it a collective effort.

Sammich
2014.09.02, 12:05 PM
we've looked at it and checked those connections...where the screws used to be, it's soldered, and that's a secure connection. so i'll pull off the top plate and see what i find

cowboysir
2014.09.02, 06:41 PM
curious to know what kind of radio you use, sammich?

Sammich
2014.09.03, 07:38 AM
i use a EX-1

herman
2014.09.03, 08:35 AM
try checking the battery contacts... found one car's contacts kinda flattened on mine... barely touching the battery... try prying / or moving it back out using a small screw driver... hope this helps...

Sammich
2014.09.03, 04:49 PM
yea that was the first thing i did, Herman. sorry i didnt relay that in the original post

herman
2014.09.04, 02:27 AM
oh... hmm... then check connections to the board (as mlemor60 mentioned) there might be a loose connection or a pinched wire... then check the fets... maybe one might be defective... try changing the motor to stock and see if it still cuts out... hope this helps

LED
2014.09.04, 03:30 AM
when the car shuts down, can you still here the rattling of the servo or is it completly dead?
It can be a few things.
1) Loose battery connection somewhere, or a wire from the switch, or the switch itself. Also check the screws for the wires going to the board.
2) short circuit on the board. Maybe a strand of a wire is touching something else. Check your board. clean it. Check where the wires from the servo leave the boad. Sometimes they are stripped to far and when putting the cover on they make contact with something else on the board.
3) check your antenna

marco_losi
2014.09.04, 03:56 AM
Hi,
In order to help you, could you clarify what you see when the car seems to die? Is the power on led still ON, does the steering still work? Or is it only the engine which seems stall?"
Marc

marco_losi
2014.09.04, 04:24 AM
when the car shuts down, can you still here the rattling of the servo or is it completly dead?
It can be a few things.
1) Loose battery connection somewhere, or a wire from the switch, or the switch itself. Also check the screws for the wires going to the board.
2) short circuit on the board. Maybe a strand of a wire is touching something else. Check your board. clean it. Check where the wires from the servo leave the boad. Sometimes they are stripped to far and when putting the cover on they make contact with something else on the board.
3) check your antenna
Hi belgian cousin, I saw your contribution after I post mine. :) Basically we do have the same question. :D Really funny, cheers, Marc

Sammich
2014.09.05, 10:59 AM
when the car shuts down, can you still here the rattling of the servo or is it completly dead?
It can be a few things.
1) Loose battery connection somewhere, or a wire from the switch, or the switch itself. Also check the screws for the wires going to the board.
2) short circuit on the board. Maybe a strand of a wire is touching something else. Check your board. clean it. Check where the wires from the servo leave the boad. Sometimes they are stripped to far and when putting the cover on they make contact with something else on the board.
3) check your antenna

Hi,
In order to help you, could you clarify what you see when the car seems to die? Is the power on led still ON, does the steering still work? Or is it only the engine which seems stall?"
Marc

if you guys read the original post, i mentioned that the car goes completely dead, no red light from the board, no steering twitching, no motor no nothing. the second i pick it up and tap it or even just lightly drop it on the ground or it hits something when it completely shuts down, it starts right back up

LED:

1. the wire from the board to the battery connections are soldered and we've checked that. i've also pulled the tabs out further thinking that was the issue, but it wasnt, the tabs are still good and firm

2. this is what i've been planning to do but i've been lazy all week to tear it apart to see what it's doing. i'm really thinking it's the wires from the board to the servo components that's loose, possibly the neg/pos wire

3. i'll be sure to check the antenna as well.

thanks!!

Sammich
2014.09.05, 11:00 AM
oh... hmm... then check connections to the board (as mlemor60 mentioned) there might be a loose connection or a pinched wire... then check the fets... maybe one might be defective... try changing the motor to stock and see if it still cuts out... hope this helps

i'll try this as well and see what's going on, but you really think a motor is going to shut down the entire car?

mleemor60
2014.09.05, 11:22 AM
As I mentioned before. Bring it with you on the 13th. We will sort it out.

marco_losi
2014.09.05, 11:39 AM
Hi Sammich,

Just one remark, I had issues with servo wires lately, the steering got crazy but the 03 is still alive! Also I ran my 03 without antenna :-) Still working.
SC on motor? the FET would burn...

In my opinion the issue is coming from the PLCC who need a reflow. Why? Because you said the issue was appearing while running so I guess the temperature has an effect. All the components on the PCB are qualified for running in high temperature (you bet :-)), so assuming there is no obvious SC due to lose wire, the only thing I see is a component which is getting unsoldered.
What component on the PCB is more likely to get unsoldered? The first one is the FET and the second one is the main IC in PLLC package.

Now you confirmed me that the whole car electronic seems dead, no LED, no steering, no engine, so I'd go for the IC in the PLCC.

Of course, before running for that conclusion let's carry out the trials mentioned earlier (verify the wire, connections and so one...).
Just a little advise, in case two connections seems very close, even if they are not touching each other, I would run a fine sharp blade between them to delimit the space. It'll remove any doubt on any weak connection.

Let us know your findings ;-)

LED
2014.09.05, 02:28 PM
2. this is what i've been planning to do but i've been lazy all week to tear it apart to see what it's doing. i'm really thinking it's the wires from the board to the servo components that's loose, possibly the neg/pos wire

3. i'll be sure to check the antenna as well.

thanks!!
Maybe if you were a little less lazy you didnt need this thread...

Sammich
2014.09.05, 03:50 PM
As I mentioned before. Bring it with you on the 13th. We will sort it out.

i doubt i'm going to make it, besides i hate to come that way with one car and not be able to fix it. thanks tho Mike.

Sammich
2014.09.05, 03:53 PM
Hi Sammich,

Just one remark, I had issues with servo wires lately, the steering got crazy but the 03 is still alive! Also I ran my 03 without antenna :-) Still working.
SC on motor? the FET would burn...

In my opinion the issue is coming from the PLCC who need a reflow. Why? Because you said the issue was appearing while running so I guess the temperature has an effect. All the components on the PCB are qualified for running in high temperature (you bet :-)), so assuming there is no obvious SC due to lose wire, the only thing I see is a component which is getting unsoldered.
What component on the PCB is more likely to get unsoldered? The first one is the FET and the second one is the main IC in PLLC package.

Now you confirmed me that the whole car electronic seems dead, no LED, no steering, no engine, so I'd go for the IC in the PLCC.

Of course, before running for that conclusion let's carry out the trials mentioned earlier (verify the wire, connections and so one...).
Just a little advise, in case two connections seems very close, even if they are not touching each other, I would run a fine sharp blade between them to delimit the space. It'll remove any doubt on any weak connection.

Let us know your findings ;-)

i'm sure i understood generally 75-80% of this post...i'm pretty new to RCs in general in dealing with tinkering with them

what's:

SC
PCB
IC
PLCC

today seems like an ideal day to check this car out and take it apart, that's if i dont work on my real car today.

Maybe if you were a little less lazy you didnt need this thread...
ok..

Sammich
2014.09.05, 09:04 PM
I was trying to upload a pic of the board but the upload kept failing. But I have it apart and the only wire that appears to have a possible bad connection is the blue wire to the far 'passenger side' of the car. ...I believe, from the abbreviation and following the wire it's the negative steering wire.

Would that wire make the entire car to shut off, because it seems like it'd just be failed steering to me. Everything else seems fine though

marco_losi
2014.09.06, 03:33 AM
SC=Short Circuit
PCB=Printed Circuit Board
IC=Integrated Circuit
PLCC=http://en.wikipedia.org/wiki/Chip_carrier

"Would that wire make the entire car to shut off, because it seems like it'd just be failed steering to me. Everything else seems fine though"
=> re-solder it and give it a try. Though I don't think it's the culprit.
Please tell me what was the result.

Sammich
2014.09.06, 07:08 AM
Will do and thanks for the break down

mleemor60
2014.09.06, 07:14 AM
Bryan. It doesn't seem to be a short circuit but an intermittent open circuit. probably in the switch by-pass. If not there maybe in the cross chassis connection. Albert recently lost one to a lifted tab that had been soldered instead of screwed to the chassis.

Sammich
2014.09.07, 08:56 PM
Thanks for the heads up. I went to the shop today but wasn't planning to so I left home without the chassis to test it out in any capacity. Maybe next weekend

Mike Keely
2015.11.16, 06:46 PM
My money is on the switch like Mike said. When you open the top cover solder across the two white wires on the right side of the board. Those two wires go to the switch. With the solder going across those two wires it jumps the switch out. After you solder it try and run the car, if it does not do it again you found the issue. If it still happens then you can remove the solder from across those two wires.

Mike Keely
2016.03.28, 04:36 PM
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