ICS M-1 problem

[Rob101]

I just revived the gun about a week ago or so and it worked great out of the box. Now on the game I go to game it I thought might as well check the rife before I go to the field, as soon as the connectors made contact the rifle started going off in full auto with the trigger on safe. I pulled it apart and made sure the lever rod for the trigger was loose and not jammed up. The MOSFET unit in the rifle was extremely hot and when I moved the trigger rod (not sure what it's called) the motor sparked.... Just wondering if I'm going to have to replace my MOSFET unit and open up the gear box to make sure nothings jammed up. I would really like to have this rifle back up and running.

[lurkingknight]

motors will spark when they turn.

this gun came with a factory mosfet? If all you did was plug in the battery and it started shooting, the mosfet is fried. Safeties in these guns are a mechanical block to prevent the physical trigger wiring from closing the circuit.

If you plugged the battery in and it ran away with the trigger not closed, the solid state switch in the fet unit has failed and it's shorting there.

Provided you don't have a cut wire making the short on the trigger path.

Not that I think would matter a whole lot, but what size battery do you use? There's a number of things that can contribute to a fet frying, and most of the oem fets that come in guns are pretty low quality that can't take massive current/voltage spikes by themselves. A number of hand built designs out there for 20 bucks are much more reliable in dealing with spiking that occurs in airsoft guns.

[Rob101]

Out of the box I had tried it with the battery I recieved it with 9.6 nicad and she worked perfect. I am not very knowledgable of aeg's, would replacing the MOSFET alone help the situation? If so what kind should I go with? I have a plug and play MOSFET I was saving for my M60 should I just toss that one in?

[lurkingknight]

no such thing as a plug and play fet that you don't have to solder in. If you plug it inline with your battery it's not a mosfet. A mosfet is a relay that interrupts the trigger circuit so you're not sending unregulated full current through the contacts that cause arcing. Instead it uses a separate circuit to detect the trigger being pulled and on a main circuit that unleashes the full current to your motor.

Also without opening your gun to see where the original is placed otherwise it's hard to choose a replacement. If it's integrated into the gearbox like the ICS mp5 pro you are basically limited to the original factory one... but you won't know unless you open it up.

If you need to ask these questions, you really need to see your local gun doc. If you're feeling that adventurous, you'll have to open the gun up and find where the mosfet is placed or find pics of it taken apart.

[Rob101]

I don't have a local gun doc, the ICS M1 is easy to access the MOSFET unit. The rifle is wired to the stock and it is located right behind the motor. I had just ordered a new MOSFET unit (ME-28 OEM) from ehobby and installed it today with ease. But as soon as I plugged the battery in again off it fires, trigger assembly removed... I have checked for cut wires loose connections.

[lurkingknight]

Don't know what to say, without it in front of me it's kind of just guessing, but it's shorting somewhere.

[venture]

Sometimes when I have an electrical problem that I cannot pinpoint, I just rewire everything and that will solve your electrical problems.