Electrical Issue in AGM MP40?

[gckmntr]

My AGM MP40 went down on me during OP: Cutlass a couple of weeks ago. I finally had a chance to take a look at it today and am not too sure of what's going on.

When it went down, it fired a few rounds before finally cutting off. When I pull the trigger, it makes no noise whatsoever (Yes, the battery was in and I flipped the switch on the grip in the right position). This makes me think it is some sort of electrical issue.

I'm not an incredible gun tech, but I can do the basics. I opened it up and looked for the obvious. No wires were disconnected. The fuse is good. I tested a second working motor and got the same results. I have not open the gearbox itself yet, as I like to avoid that when possible.

Anyone have any ideas? I imagine that many of you have had MP40 issues at some point. Are there any obvious points of failure I should check? Any and all help is appreciated.

[HornetWSO]

I've had an MP40 that has been very finicky from the get go. I've never actually fielded it, as each time I prep it prior to a game, it works, and then when I test fire it for thegame, no joy. Frustrating to the point that I dont consider this particular MP40 an airsoft gun, but a prop.

I've spent literally hours trouble shooting this fine engineering.
What I did find on my personal weapon, is the forward screw that holds the bakelite forgrip impacts my gun. If it is tightened too much (in my case snug), it puts presure on the electrical block underneath , and prevents the gun from firing.

I dont know if this is a design flaw, or just an issue with my personal weapon.

Figured I give you my 2cents worth of S2.
hope it helps.

[volkssturm]

Has the gun seen a lot of use, particularly semi auto? One thing that happened to me (on another gun, not an MP40) was there's a metal piece inside the gearbox that slips between two contacts when you pull the trigger. With a lot of use it gets cruddy because of sparking everytime you make the connection. I cleaned it off with some emery cloth. Before digging into the box I'd double check all the connections. If you can get a voltmeter you can check that the wires aren't broken under the insulation.

[jimmiroquai]

It's the on/off switch. Just bypass the switch and it will start working again. Just be careful as it will now always be "on".

[gckmntr]

Thanks for all the responses.

I cracked open the gearbox today. A glob of grease from the MASSIVE over-greasing fell into the trigger contacts and caused them to get scored. I wiped them down and put everything back together and it is shooting fine. We'll see how it does back in the field, but it looks like case closed to me.