He's dead Jim... (He being a Echo1/JG G36C)

[sandman]

So this is the last stab before I send it to a surgeon. Its an Echo1/JG G36C with about 4 lowcap mags though it... virtually brand new.

After replacing a spring I've found the V3 mechbox to dead, died, defunct and deceased. No clicks... na da...

Using a multimeter I've check the battery - check

I've followed the circuitry to the mechbox. All wiring and fuses are good and are circuited tested with the multimeter - check

The motor runs - check

The I manually cycled the trigger circuit and ran the motor - check

Before I put the mechbox back together I performed a continuity check of the entire system and all was good - check

After the mechbox is together I ran the gears... no binding - check

But when I pull the trigger there appears to be no connection in the circuit... ie dead. To me it appears like the trigger is not forcing a contact of the two positive nodes and as such not completing the circuit.

Any suggestions of what the problem may be or even better a good pic of the switch for reference. Is it possible I'm missing a piece somewhere? Tips? Hypothesis? Wild ass guessing?

[AngelusNex]

Had this happen with a brand new Kingarms trigger contacts set, when you pull the trigger, the contact that completes the circuit moves forward.... the two pieces it touches may just be to far spread. All i did to remedy this was bend them inwards, close but with at least 1-2 mm between.

[kalnaren]

Originally Posted by AngelusNex

Had this happen with a brand new Kingarms trigger contacts set, when you pull the trigger, the contact that completes the circuit moves forward.... the two pieces it touches may just be to far spread. All i did to remedy this was bend them inwards, close but with at least 1-2 mm between.

+1

Had this exact same thing happen to my CA G36.

[theguy]

Does it only do this when the mechbox is in the lower receiver/grip? Or does the trigger still now work when the mechbox is out of the lower

[sandman]

Originally Posted by AngelusNex

Had this happen with a brand new Kingarms trigger contacts set, when you pull the trigger, the contact that completes the circuit moves forward.... the two pieces it touches may just be to far spread. All i did to remedy this was bend them inwards, close but with at least 1-2 mm between.

Good thoughts, I had them too. They appeared to make good contact when I was testing continuity but I gave both of the contections a tweak for good measure; however it made no difference. To me it's almost as if the 'plunger' piece (for lack of a better word) is not advancing far enough when the trigger mechanism is actuated?

Originally Posted by theguy

Does it only do this when the mechbox is in the lower receiver/grip? Or does the trigger still now work when the mechbox is out of the lower

As soon as the two halves of the mechbox are joined it stops working. The trigger mechanism is working. However there is the sound of a mechanical click. Almost like the sound of the trigger lever passing over the plastic instead of advancing it. Not sure what to do about that though?

[Thenooblord]

are you sure that the problem may not be in the selector contacts? bend them out a bit as well just to be sure

[sandman]

Originally Posted by Thenooblord

are you sure that the problem may not be in the selector contacts? bend them out a bit as well just to be sure

It's not the contact directly but I beilieve its related to the switching assembly. When the trigger is pulled the part of the swiching assembly that travels forward is rising and then does not catch the trigger latch.

The box will cycle for one round and then not catch again (which is where the clicking sound was coming from; the latch is just catching the switch carrier but then rising and jumping off). If I hold down the carrier, with a flat head screw driver for instance, it runs just fine.

I can't see where there are any pieces that have broken off to allow the switch carrier to rise. Maybe its just a faulty switch assembly and needs replacing? It's virtually brand new though and was working before I opened the mechbox...

Is there a specific peice that is designed to restrict the switch carrier from rising so that is maintains in contact with the trigger latch?

[AngelusNex]

AH that sounds like something is worn in the fire selector or selector plate, causing it to hold the cutoff lever in the wrong spot.

[sandman]

Originally Posted by AngelusNex

AH that sounds like something is worn in the fire selector or selector plate, causing it to hold the cutoff lever in the wrong spot.

It's a virtually new set up, maybe 5 mags through it. I have replaced the Selector Plate with a new KA model (broke the original putting it back together) but there was the issue with the previous plate.

The issue appears to be the switching assembly being forced up by the trigger and skipping instead of being force forward and making contact.

There doesn't appear to be anything missing from the switching assembly though. And without a good pic of it it's difficult to determine why it is rising instead of travelling forward.

I did put in a 3/16 screw to hold the switching assembly in place that was not included for some reason on the Echo1/JG G36C's but that shouldn't effect the carrier travel.

Are there any pics of the switching assembly installed that are availble I could use for reference?

[Con Murder]

Test your motor with the multi-meter while it is hooked up to the gearbox (so all wiring is laid out as it would in the gun) and free to run. If the motor works and the lines to your mechbox work than this will tell you if its the trigger contacts/selector switch. Replace what ever is not working, I've done the bending back of those tabs to fix a dead gun and its usually pretty obviouse, and if its not moving right its best to get a new one.

[Kos-Mos]

You got a defective trigger unit.

The carrier is probably poorly molded and the trigger just skips on it.
The movement you describe should be caused by the cut-off lever. If you hold the cut-off out of the way, does the carrier still jump up?

If so, then you just have to get a new trigger unit.