Which fet is forward?

[Z-Nagual]

Ok so I decided to do a fet stack. One side works (reverse[pushing forward on trigger]) but pulling the trigger back….. nothing. which fets run forward? I dont want to do the lot again :dead:. Please help.

[betty.k]

run it in reverse until one stack warms up. the cold one is forward:smiley2::8ball:

[Z-Nagual]

ahh…. thank you. why didnt I think of that myself:dead:.

[betty.k]

‘cos i’m a lateral thinker:smiley2::D:8ball:

[jamiekulhanek]

I thought that there was no foreward FET, both FETS can reverse polarity, therfore giving you foreward and reverse.

It sounds like one of the signal pins (pins 2 & 4 on the FETs) are either not connected or have dry joints, either that or you damaged them somehow, static or too much heat.

[Z-Nagual]

I’m not sure exactly but that sounds pretty spot on because my connections are dodgy at best(my soldering iron has an enourmous tip). But what do you mean by “dry joints”. And how do you determine which side of the fet is which. Does the orientation of the writing determine it or the little dots that are pressed into the plastic? All I know is I have installed a 2×2 stack in my overland and if I put batteries in, without even turning it on it starts revving in reverse. turn controller & car on and everything works exept forward. should i just get a finer tip and start again?:angry: It’s driving me insane:sad::angry:blackeye::dead:

[Z-Nagual]

And as for reverse polarity yes thats right but mine only go in one direction.When I say reverse I mean Reverse on the control.

[jamiekulhanek]

Dude maybe you need help, I install and test FET mods for a reasonable price, have a think about it…

It is possible that you may have damaged the FETs in the install/run process.

-For soldering FET stacks, a fine tip is what you want.

-Dry joints are joints or soldered connections that actually are not connected, you generally can’t see a dry joint.

There is 3 ways I use to check the orientation of the FETs,

-The Indentation on the left hand side
-The orientation of the text
-The Beveled edge

[Z-Nagual]

Thanks man. I’ve just taken the stacks off and I have a finer tip so I’m going to start again. I have successfully soldered single fets on before but not a stack. The problem was my tip was too big to fit in between the stack of fets and the big black box next to them. I melted the side of the ‘big black box’ a bit. Is it possible that has something to do with it? Have I screwed up yet another Z? Oh the agony:dead:. If I mess this up I might think about seeking professional help. Here I go again………

[jamiekulhanek]

Firstly, remove that “big black box”

[Z-Nagual]

Mission Accomplished:smiley2:

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