Replacing Quark's fried brains... - RC-Monster Forums

zeropointbug · **Replacing Quark's fried brains... -** 10.18.2007, 06:07 PM

Hey guys, you may know that my wicked Quark had been murdered on me in action... long story short, I remembered that I have spare Quark brain board that came off my DOD Quark from S&T. I just hope that it is still good, and if the fire fury did not damage any of the IC's.

I did buy a Quark from AAngel, which is in transit, but it would be very nice if I could get this Quark to run again.

The only thing is that I have never actually DE-soldered connections like this, so anyone's help with that would be greatly appreciated.

Note how there was a short circuit from the brain board onto the cap buss bar, a good amount of solder was melted in the process... and I can tell you that I took a good amount of heat from a 250watt iron to melt solder on that buss bar. It must have been quite the nasty short, yet my batteries are still alive, thankfully, I just hope their performance has not been compromised.

zeropointbug · 10.18.2007, 06:09 PM

Here are pics of the replacement brains (hopefully). There is some burning FET residue caked into the three phase controllers there, hopefully it did not damage them from heat.

sikeston34m · 10.18.2007, 06:15 PM

Hey ZP. I hope you can get your controller going again. That sure was an awesome setup.

On the brain board, I think I would see if I could clean off that fet "residue". That stuff is probably conductive and could give you problems even if the underlying components are good.

Good Luck with this project.

zeropointbug · 10.18.2007, 10:58 PM

Yeah, I wonder how I could get the residue off, i agree that it could be slightly conductive and/or capacitive.

Can anyone give me some insight on how to de-solder the 4 soldered joints at the motor out end of the board?

sikeston34m · 10.18.2007, 11:18 PM

Aaah now I see where you're talking about on the desoldering.

Get some Desoldering braid from Radio Shack. It's pretty handy stuff.

http://www.radioshack.com/product/in...entPage=search

Once you have the solder removed it should come apart rather easily for you.

I hope this helps. Good Luck.

zeropointbug · 10.18.2007, 11:23 PM

Okay, that should work great. Thanks for the help!

zeropointbug · 10.22.2007, 11:09 PM

Well, I tried replacing the board with the other board I had left over from the second Quark I got back from S&T that cogged BAD right from the start, it wouldn't even move, then it started on fire....

Anyways, it looks like it is doing the same thing mounted to these FET's too. I did a table top test and it has no reverse, and acts so stupid, like no neutral range (yes i tried reprogramming it), and when I apply brakes it goes into COGZILLA! WHOW, I unplugged it, and said that's enough, I don't want to ruin the FET board.

'no mods' was kind enough to send me one of his Quark brains, so hopefully that one will work?

Once I got the board off, I noticed how alot more surface components were fried in the short than I thought. All the caps it looks like!