Go Back   XmodSource.com > Xmods > XMOD Electronics
Register FAQ Members List Calendar Gallery iTrader Today's Posts

Reply
 
Thread Tools Display Modes
  #21  
Old 12-01-2009, 01:45 PM
raven50x raven50x is offline
New Member
 
Join Date: Nov 2009
Posts: 12
Trader Rating: (0)
Default

Thanks for the advice. I rubbed the bubble on he top FET off and it was sandy- not glue... So it may be bad- I don't see a hole in the FET but I can probably assume it's bad.

So where do I begin with changing all the FETs??
Reply With Quote
  #22  
Old 12-01-2009, 01:48 PM
Action B's Avatar
Action B Action B is offline
Elite member
 
Join Date: Feb 2009
Posts: 424
Trader Rating: (8)
Default

To be honest I can't tell from the pictures. I do have a diagnostic procedure I go through to determine if a FET is properly installed. I've never used it to check if there was a bad FET before so I'm not exactly sure if it would work from that. I imagine that it would because it tests for continuance at all FET legs with other known spots that should have continuance on the board. This being said I'm not guaranteeing it will catch your problem and its going to take me a until this evening to get it written up and posted. Here is one for the EVO board as an example of what it will look like.

http://farm4.static.flickr.com/3427/...5015d29e_o.jpg

I can go ahead and make one if it will benefit you so let me know. It does take a bit of time so I don't want to make it if its not useful.

Other than that, I have video tutorials for FET changes, if thats any help. If not I'd be willing to cut you a really good deal on FET installation due to your unfortunate circumstances.

Last edited by Action B; 12-01-2009 at 01:52 PM..
Reply With Quote
  #23  
Old 12-01-2009, 01:56 PM
raven50x raven50x is offline
New Member
 
Join Date: Nov 2009
Posts: 12
Trader Rating: (0)
Default

@Action B- I don't mind doing the labor myself for FET installing. And you don't have to make the continuity directions (I appreciate it though). I mainly need to know which FETs I need for getting both sides of the board replaced.

Last edited by raven50x; 12-01-2009 at 02:01 PM..
Reply With Quote
  #24  
Old 12-01-2009, 01:58 PM
Action B's Avatar
Action B Action B is offline
Elite member
 
Join Date: Feb 2009
Posts: 424
Trader Rating: (8)
Default

Quote:
Originally Posted by raven50x View Post
Okay, so that test would just make sure all my traces are still good but doesn't tell if the FET is bad itself... I guess it's worth a shot.

And about replacement FETs, Are there tutorials for replacing both the motor and steering FETs for gen1? I feel like that's where this is leading.

Thanks again guys
Well I think when FETs fail they actually destroy the pathways inside the FET itself (they burn up), which will remove continuance. Don't quote me on that though I'm a pro at taking them off and putting them on but behind how they actually work

The videos I have are mini-z boards and only the motor FETs, however, the same technique works on all FETs. The techniques from this video I modified slightly to my own liking and use them in my electronic services.
Reply With Quote
  #25  
Old 12-01-2009, 04:59 PM
texan_idiot25's Avatar
texan_idiot25 texan_idiot25 is offline
Yes, 1945 Cadillac Tank
 
Join Date: Jun 2006
Location: Austin, TX
Posts: 3,366
Trader Rating: (5)
Send a message via AIM to texan_idiot25
Default

I'd go ahead and replace the FETs anyways. The ones you buy through AM are of higher quality, and while your at it might as well double stack it. Liths will stress FETs more anyways. A lith xmod with a normally FET safe motor will still burn them if it's pushed hard enough. May not be externally damaged in the normal way that a motor would do, but the liths may have done a number on them internally.

I remember what caused the steering problems. It was while I was building my S10 Crawler, and had to rewire the servo motor back on. The Trucks used a split-apart servo, where the motor and pot were not packaged together. I had wired the servo motor backwards, so when it turned on to center itself, instead of going say for instance to the right, it went left and the pot just kept feeding it to go right (which of course, was left).

Why your's has done this now, not sure. But again, may have to do with the damaged board.
__________________
You know what I'm gonna do? I'm gonna get myself a 1967 Cadillac Eldorado convertible, hot pink, with whale
skin hubcaps and all leather cow interior and big brown baby seal eyes for headlights. Yeah! And I'm gonna drive
around in that baby at 115 miles an hour, getting 1 mile per gallon.

I may be king of the idiots, but my kingdom is vast and my subjects are everywhere
Reply With Quote
  #26  
Old 12-01-2009, 06:21 PM
raven50x raven50x is offline
New Member
 
Join Date: Nov 2009
Posts: 12
Trader Rating: (0)
Thumbs up

Thanks again guys

I really appreciate the support for my problem. I actually ran the EP by a technician I know, and he checked the wiring/circut connectivity/FETs. He said nothing looked bad. (he normally repairs TV/stereos, but I guess electronics are electronics)

So I basically gave up, and started looking for replacement EPs (which btw are REALLY hard to find).

I put my batts one last time onto my poor EP, and turned it on... no worky. So I left it in to see if the FETs would just burn out while I ran the remote control, and nothing...
THEN the motor suddenly jumped and started spinning! I ran the remote control the opposite way and it started spinning the opposite way! I tested the steering on the remote control and it worked too (still jitters a bunch though).

I am assuming I must have some loose wiring somewhere, So i'm going to try resoldering everything. Again, I really appreciate the community's help.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

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


All times are GMT -4. The time now is 11:41 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.