I picked up a used MCX about 5 or 6 months ago, it was my first heli.

My 13 year old son and I both learned to fly with it. It has been through an awful lot, and the only thing that ever broke until recently, was one upper blade.

It had started to lose power, but was still flying decent. A few weeks ago, I decided I would give her a couple new motors. After installing them, I took off like normal, and managed to hit the Christmas tree. It broke the head on the inner shaft, where the flybar attaches, so I ordered a new inner shaft.

I got it installed today, and she was working fine, but still down on power. I've been trying to narrow down the loose of power, and thought it may be the batteries. I had read in the MCX thread that some people replaced the battery connector and wiring, so I ordered one when I ordered the new inner shaft.

Anyway, I took the heli apart tonight, and was going to replace the battery connector and wiring. Well, the area where the wires attach to the board is very small, but I finally got the wires in and soldered. I couldn't wait to try it, to see if it had more power.
I turned on my DX6i, and plugged in the battery... I noticed the light didn't come on the heli like its suppose to after hooking up the battery, so I went to unplug the battery, and it was hot.
I noticed the battery was swelling up, and just as I was unplugging the battery, it popped

The only thing I could figure out was, I must have gotten the solder on the two wires bridged.

I have decided it is time to cut my loses, and give her a decent burial...

I had really become attached to that little heli. I guess its a good thing I ordered a new MCX2 on Friday. That should help ease the pain of my loose, once she arrives

The 2 has flashing lights.

You can still desolder the wires and try again. If you have one of those things they use to suction solder as they desolder a connection you can just desolder those wires making sure you get all of the leftover solder off the board and then carefully resolder and inspect for bridging before installing a new battery, but you don't really need that suction thing if you can get all the solder off with your iron. Just inspect it closely for bridging once you're done.

You can get a cheap continuity tester and test for continuity (bridging) between the two wires before plugging in the batt. I've seen them at walmart for around $4.

When you plug in the battery hold it for just a few seconds and you will feel it get hot if there is a short. In that case just disconnect it right away. You might want to connect the battery someplace where a fire won't be hard to deal with like out in the middle of the driveway (just in case).

Here's what a continuity tester looks like:
http://www.sears.com/shc/s/p_10153_1...u=SPM655566601

Rip

Originally Posted by Vimd

Rip

No, it doesn't Get To Rest, until Killbucket SAYS it Rests. ROFL.
Overdline has the right Spirit- this copter is Too Young To die.

New drive motor(s). (I've zippo familiarity with small 4-channels) I think your problem is more likely them, given the stated age and enjoyment.

BUT- a whole fresh, new airframe makes better economic sense.

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Originally Posted by rick.benjamin

The 2 has flashing lights.

I know. I can't wait to fly it with the lights off

Originally Posted by overedline

You can still desolder the wires and try again. If you have one of those things they use to suction solder as they desolder a connection you can just desolder those wires making sure you get all of the leftover solder off the board and then carefully resolder and inspect for bridging before installing a new battery, but you don't really need that suction thing if you can get all the solder off with your iron. Just inspect it closely for bridging once you're done.

You can get a cheap continuity tester and test for continuity (bridging) between the two wires before plugging in the batt. I've seen them at walmart for around $4.

When you plug in the battery hold it for just a few seconds and you will feel it get hot if there is a short. In that case just disconnect it right away. You might want to connect the battery someplace where a fire won't be hard to deal with like out in the middle of the driveway (just in case).

Here's what a continuity tester looks like:
http://www.sears.com/shc/s/p_10153_1...u=SPM655566601

I had thought about trying it. The area where the wires are soldered is very small, and there isn't much room between the two wires. My eyesight isn't the greatest anymore, and my soldering iron could stand to be a little smaller.

I think I will pick up a continuity tester when I go to pick up a volt meter.
I've never had any problems before, so I never thought about having any problems after soldering. Now I know better

Originally Posted by Vimd

Rip

Thanks. After all the time I've spent with it, and after the little incident last night, it was like it was saying to me, Let me go. I'm done

Originally Posted by killbucket

No, it doesn't Get To Rest, until Killbucket SAYS it Rests. ROFL.
Overdline has the right Spirit- this copter is Too Young To die.

New drive motor(s). (I've zippo familiarity with small 4-channels) I think your problem is more likely them, given the stated age and enjoyment.

BUT- a whole fresh, new airframe makes better economic sense.

Support RCGroups. Become a Private Sponsor.

I do have a hard time giving up on things, especially when they have been loyal to me.
It is true though, that I would be money ahead buying a new one. I wish the boards were only about 10 or 15 dollars, I would get one. They even come with a new battery connector already installed
But 59 dollars is a little much. Heck, a new BNF MCX is only 79 dollars. There have been a few smokin deals on used ones in the classifieds lately, but I've been a little slow to see them, and they don't last long

It's a shame these board are so overpriced. I bet they cost no more than a few dollar to manufacture...

But if no "magic smoke" came from your board, it may still be fine, just needs a better solder job.

Originally Posted by Piper Cub Man

I know. I can't wait to fly it with the lights off



I had thought about trying it. The area where the wires are soldered is very small, and there isn't much room between the two wires. My eyesight isn't the greatest anymore, and my soldering iron could stand to be a little smaller.

I think I will pick up a continuity tester when I go to pick up a volt meter.
I've never had any problems before, so I never thought about having any problems after soldering. Now I know better



Thanks. After all the time I've spent with it, and after the little incident last night, it was like it was saying to me, Let me go. I'm done



I do have a hard time giving up on things, especially when they have been loyal to me.
It is true though, that I would be money ahead buying a new one. I wish the boards were only about 10 or 15 dollars, I would get one. They even come with a new battery connector already installed
But 59 dollars is a little much. Heck, a new BNF MCX is only 79 dollars. There have been a few smokin deals on used ones in the classifieds lately, but I've been a little slow to see them, and they don't last long

Are you sure you blew the board ? it sounds to me like you bridged the solder connection to the board.in which case when you connected your battery very little if any current went into the board. In al liklihood the current flowed from the battery, across the solder bridge, and back to the battery, i.e. a direct short circuit. Thats why the battery got hot and ballooned. In which case it is very likely that the board is still good.

What I would reccommend is that you inspect the board with a magnifying glass or a jewelers loupe. Pay particular attention to the area where you did the soldering. Look to see if the battery connection points are bridged. If they are then unbridge them with a clean sharp narrow point soldering iron and some de-soldering wick. Also check any components in the vicinity of the connection. If nothing looks cooked then your board it probably still good. Resolder the connection carefully. Use magnification.

P.S. after you resolder the connector it is a good idea to put an ohmmeter across the terminals and see what kind of reading you are getting. If you see a very low resistance... close to 0 ohms... then it's likely you have a short.