Help

[jasonx9]

I was driving my car around without the body it got stuck under something and with the motor being exposed it knocked the top capacitor off the motor and I switched motors and it still isnt doing a single thing no throttle at all steering is perfect but no motor responce at all.

[mycrors4]

check if the negative and positive are put into the right slots

[jasonx9]

Thats not the problem unless for some strange reason the positive became a negative when that happend lol. I even tried putting my stock motor back in.

[Action B]

Lets narrow down your problem. Sounds like you might have a FET problem.

1. Grab your multimeter, if you don't have one buy one ($15 at walmart)
2. Remove the motor wires from the board and set aside, or just remove the motor entirely.
3. Turn car and transmitter into the ON position, verify steering works
4. Touch multimeter leads to + and - motor wire connector points on board.
5. Have a friend pull the throttle trigger on the transmitter, you should see a positive voltage for forward and negative for reverse. Since the board operates at 4.8V you should expect around 5 volts.
6. If you get nothing its probably a FET issue. Inspect them for damage.

[jasonx9]

How do I know the fets are messed up? What do I look for?

[Action B]

Originally Posted by jasonx9

How do I know the fets are messed up? What do I look for?

A small bump/bubble on top or a crack, also a weird smell. Usually it burns when it happens but not always. Only check throttle FETs.

Here is an image of the test I'm speaking of.

Forward throttle:


Reverse throttle:


Brake should have 0 voltage.

Hope this helps.

[jasonx9]

Which are the motor fets and I am going to order 2 sets off atomicmods but need to know which one is witch I think i see a bubble on top of the ones right next to were the motor goes on. Which fets should I get to replace them since one fo them is probably fried I want to just stack them now I found these http://cgi.ebay.com/Xmods-Xmod-Evo-T...item2303aab509 I want to know if these are what I need.

[Action B]

Originally Posted by jasonx9

Which are the motor fets and I am going to order 2 sets off atomicmods but need to know which one is witch I think i see a bubble on top of the ones right next to were the motor goes on.

Did you do the voltage test I just posted? What were the results? I strongly suggest you do this before blaming FETs.

There is a small dot in the corner of all FETs. This is the orientation indicator.

Here is a link to a pic of the board. The throttle FETs are on the left picture of the board on the bottom right. Also, notice the orientation dots. Those are normal.

http://www.flickr.com/photos/3283716...84440/sizes/o/

[jasonx9]

waiting for my dad to bring it over.

[jasonx9]

It has a 1.26 positive and the same negative I am guessing they are fried. Need to know which fets to buy and what soldering iron I should pick up to use or will a regular one do it?

[Action B]

Originally Posted by jasonx9

It has a 1.26 positive and the same negative I am guessing they are fried. Need to know which fets to buy and what soldering iron I should pick up to use or will a regular one do it?

From my experience they will show 0 when they are fried. Check your batteries. That is the voltage you would get if one battery was backwards. Try new batteries and check batteries voltage at the board. it should also be above 5 or its a problem with batteries.

[jasonx9]

I got liths I measured those and there around 8. Let me do a re check but what fets do I need to get for a upgrade?

[Action B]

Originally Posted by jasonx9

I got liths I measured those and there around 8. Let me do a re check but what fets do I need to get for a upgrade?

http://www.atomicmods.com/Products/X...et__10578.aspx



* 1) IRF7324 FET P-Channel
* 1) IRF9910 FET N-Channel

Or you can get them from www.irf.com wholesale

[winner]

Do you have the skills to stack fets? It's not something every one can do on there first try.....

[jasonx9]

Just measured again and got a 1.26 for foward but when put to reverse it was around a .36. I measured my batts and it was at 8.13V

[winner]

Originally Posted by jasonx9

Just measured again and got a 1.26 for foward but when put to reverse it was around a .36. I measured my batts and it was at 8.13V

sounds to me like the fets are about to blow, but I'm not a pro like action b

[Action B]

Winner your saying some nice things about me and I'm not really sure I deserve it lol. For real though I think your right.

I'd try to switch those FETs then if you have already tried a new transmitter. I'd go for it at this point. I think one of them is already damaged. If you need the FETs done, you can PM me. If anyone else disagrees feel free to post any alternative tests. For me, when the board is definitely getting full voltage and the forward/reverse throttle is pretty dismal from the board leads, I try the FETs next. DSMers gotta look out for each other so let me know.

[lol]

Did you set the multi-meter correctly? There are like over 9000 settings.

[jasonx9]

I am thinking about ordering them up today. I am wondering if my soldering iron will be good enough its the one from RS I think its 15W. But I want to attempt it myself just because I got to learn some how you know. What kind of dsm do you have I forgot if you have told me. Like you said anyone else that has a defferent test for me to run before I make this decision chime. But thanks for all them help man.

[lol]

If it can melt solder then it will work. Im using a 60W Soldering Iron, the tip got melted off from use.