Did Li-Ion upgrade on Gen1, mis-wired.. help!

[raven50x]

You can see from the title what a noob I am.
Basically, I had a perfectly working XMOD Gen1 w/ the stock 4AAA RS batteries. I decided to do a Li-ion batt upgrade, so I ordered them and when they came in- I followed this tutorial:

http://www.atomicmods.com/Categories...tallation.aspx

The thing is... I turned it on and nothing happened. I opened everything back up and looked back at the wiring and found out that I put the (+) and (-) for the wiring in the right places.... I just swapped the motor output and the battery inputs. (I say just, lol )

I have a feeling something may have burned on my EP. So I resoldered the wires to the correct places and now the motor won't run and the steering will sometimes turn only to the left and stay there.

Basically, take the left side pair and swap it w/ the right side pair... and you end up with what I did. Batteries and all...

Help?

[TheB1GDude]

Hang on... I'm still trying to get my head around exactly what you did...

So on your first go you ended up with:

* Li-Ions going to motor
* Motor connected to board power

So when you connected the Li-Ions to the board and turned it on you had all the power going into the motor terminals?

Take a look at the FETs and see if they smell funky or have browning around them in the glue or if they look melted it should be fairly easy to tell if you've damaged them.

[raven50x]

Thanks for the quick reply. You do have it understood the way I had it hooked up. I'm not sure what smell I should be smelling, but the FETs on both sides of the boards don't look any different than before... I pulled my batteries out right after I found out it didnt run (within 20 sec). So it may be bad i guess?

There's no visible burn or melt on any of my FETs

[TheB1GDude]

It would smell bad... strong acidic smell, really noticeable if you smoked them.

It might just be a bunch of bad connections so recheck all your wiring, your description of the problem makes it sound like the POT wires are loose and thats why your steering is locking up but its hard to tell.

[raven50x]

http://img37.imageshack.us/img37/3493/pb300155.jpg

Sorry about the quality. Those are my FETs

[TheB1GDude]

Doesn't look as though you have any obvious burn marks so first things first I would say check all your wires.

[raven50x]

Thanks again for the help B1GDude. I only resoldered the same 4 wires for the motor/battery wiring. Where are the POT wires you speak of?

I'm assuming it's the wires coming out of the steering box? (sorry, I'm not too familiar with what they're called)

[TheB1GDude]

Yeah you will have a totla of 5 wires coming out of the black steering box, 2 will be power, the other 3 will be for steering, check all 5 to make sure none are loose, you might be able to fix your steering issue but the drive problem might be terminal... might be time to look into a new board, maybe go for a micro-t board....

[raven50x]

Yeah, I see the wires for the POT. They all look connected, a thin red and thin blue goto two seperate FETs and the other three goto their respective parts on the board.

I am able to get the steering to go all the way to one side each time now. If I put the batt in and turn the power switch on, the steering will turn all the way to the opposite end from start. Then I can switch the power off, then on again- and the steering will go all the way to the opposite way.

What is this micro-t board you speak of? Will it get my XMOD back up and working?

*the steering does this by itself* ^^^ not through remote control

[mr.hotrod]

Not your job.

[texan_idiot25]

I can almost promise the motor FET is damaged. Photo isn't clear enough to see.

As for the steering, I'm drawing a total blank but I know I had this issue before. But that might have been a sign that it was toast.

Did this board work 100% before?

[raven50x]

yes, the board worked fine before I did the wire upgrade on the board for my Li-ion batts. The only thing wrong before was the steering jitters- but i have a feeling that this is different.

From the looks of the FETs, they are flat and have the white grease from the heatsink on them. No burn or warping. I am willing to change the FETs for the motor and the steering, I just don't know where to begin because atomicmods lists two different model FETs and there's stacking and not... and all that jazz.

I'm not too savvy on the parts, but I have a soldering iron and plenty of solder so I'm not scared to change some FETs... I just don't know where to begin as far as which ones and how many for my gen1 Li-ion setup

[Action B]

I have some fairchild 8858s I can send you cheap if you need some FETs. They are better than the FETs that atomicmods sells. 2x2 of these will handle any motor. Just PM me if your interested. I also install them but if you want to give it a go then I have some video tutorials I can send you.

[raven50x]

thanks action B, but I need to know what will help both the motor work again AND get my steering back in order. Changing just the FET for the motor will only get my motor back up right?

I Dont know if i've screwed up my whole steering box.

[TheB1GDude]

I would highly doubt that any other damage has been caused, everything you stated so far seems to be related to fried FETs not being able to handle current, replacing the FETs for both steering and drive should take care of your issues, or you look into a Mini-Z / Micro-T board as replacement which on the whole will make you XMOD handle and perform better, personally I can't solder FETs to save my life so I'd just replace the board

[Action B]

I'm really skeptical that you blew both a steering and motor FET at once. I've never seen a FET go bad thus far that didn't show physical damage to the top of the FET such as cracking or a bubble. Do you have a multimeter?

[raven50x]

@The B1gDude- I was wondering if it'd be worth it to just buy a new xmod since theyre only like $39 on sale now, lol. Im not sure how much a new board goes for, but is it worth it compared to a new car?

@Action B- Yes I actually do have a DMM. I regret not using it to dbl check my wires like in the tutorial. There's something about modding that makes me act before thinking.

If you can give me a brief rundown howto meter my FETs for steering and motor, that'd be great.

Thanks again for the help guys

Some better pictures of my FETs:

[TheB1GDude]

First photo bottom FET looks like it has some damage.
Second photo I can't get to load...

[raven50x]

Originally Posted by TheB1GDude

First photo bottom FET looks like it has some damage.
Second photo I can't get to load...

You might have to reload the link, they both work for me.
I didn't think it was damaged- I guess it could be possible... but I also know that there was glue around that area that held the plastic cover on- so it could be some glue. let me see if it comes off.



Rubbed off that sticky stuff with a paper towel. Should there be a crack if it's bad?

[TheB1GDude]

Bottom FET in last photo where the blue wire is solder to the FET leg, see all the browning in the sealant around it.... thats because of two much heat, that might be the damaged FET right there or you might have got a little close with the soldering iron.

Top FET also looks like it has a bubble in the top left corner.