CTW MX-2 No response from trigger

Hey fellas. I bought my gun a few months ago and haven't played with it much, it has been working great in test environments, but today in the field it sort of... pooped out. It acted like the battery died - or at least that's how I'd describe it if it were not a CTW (I'm unfamiliar with the internal parts of the CTW). I didn't have any backup batteries besides some partially charged 9.6V NiMH, so I just switched to my backup gun - after charging the battery when I got home, the gun still is not firing. The blue light on the ECU lights up as soon as I plug in a battery, the trigger pulls but the motor doesn't activate at all. I'm unsure what the problem is - I would usually describe it as maybe a bad fuse, but it's possible a wire is bad or something else. One thing is that with the upper off, the sector gear (I assume that's the correct terminology) does seem a little... loose. It has just a tiny bit of wobble on the axis perpendicular to the direction of spin, and that worries me.

The battery is a Tenergy 12.8v LiFePO4.

Any help/advice is appreciated. Thanks!

Dont worry about the gear - a little lateral movement isnt an issue.

If the blue light is on then its not your fuse......try the following:

Open the gun, connect battery and you should get a blue light.

Push the bolt catch and pull the trigger - you should get some action.... if not then its either of the following:

Locked gearbox -
Can you move the sun gear (the thinner one of the 2 gears that are sticking out of your gearbox) with your thumb?
Motor Issue -
a loose connection on the motor (take the plate off the bottom of the handgrip and make sure the big 2 silver wires are connected to the terminals) OR your motor has gone....

To check the motor, remove the handgrip by pulling it off, and spin the inner bit (the long thing that moves round and round) a few times - connect battery and try again...

Let us know what you find.

The sun gear is completely immobile, can't get it to budge (I didn't muscle it too much but sufficient for a test). The motor is connected, I haven't checked the motor itself yet, I'll get back on that.

Many thanks so-far!

Spun the inner section of the motor, after reconnecting the battery the gearbox rotated once fully on semi, then returned to not responding at all. I'm unsure exactly what it means, but it suggests to me that the motor went out. This isn't going to be a very inexpensive fix, is it?

Thanks again.

You may be in luck - if the sun gear is immobile then I would 'suggest' that the sun gear has gone.

The reason for this is that the motor is VERY strong, and you should be able to spin the sun gear manualy - but if you cant and the motor can then I would suggest it is a gear problem.

You will probably find that if you open the gearbox up, that the Sun gear which is made in 2 parts and 'stamped' together has either come apart and is wedged in the planetary gears OR has re- locked itslef together but not at the correct angles and so the gearbox wont move......

Keep us updated on what you find.....

I will take a look - is there a diagram I can refer to for the inside of the gearbox? I open normal AEGs all the time but never something of this quality.

Could it be the motor brushes? Maybe moving the motor may have re-established contact where there was none before? It is unlikely, but possible that the brushes could have worn out. Of course I'm not even sure how exactly this particular motor works, it might not even be possible that it's the brushes, just throwing out things that I've read.

Thanks again.

I now have it working such that I can move the sun gear by hand - I'm not entirely sure there was ever anything wrong with it, I may not have been using enough muscle in the first place. However, the issue continues: I can consistently spin the motor by hand and almost every time it responds right after, but only for a few trigger pulls. If I set it to auto and it does spin, it won't fail as long as I have the trigger back. There was a little bit of carbon on the inside of the hand grip, I cleaned it out, but unfortunately I'm not knowledgeable enough about motors to know what that means.

Thanks again.

I'm going to try to replace the brushes and see if that fixes it - if it doesn't, I know that there are a few possible motor upgrades I could get when replacing the motor. Is anything better to look into than something else?

While I'm at it, what are some recommended upgrades for the gun in general? Parts that break more often than others, things that would make it run better, etc.

Thanks again.