I don't have the ascu2 but my mp5 install with the original ascu went in smooth as butter. I did have a small hiccup with the selector plate but that was easily remedied with a new one.

Ryan, assuming you followed the instructions, did you mod the gearbox at all near the selector plate? Is there 100% clearance from the contacts and the gearbox? Double check that the outside of the selector plate is also insulated from shorting out.

Btw, I haven't looked at my mp5 in a while, nor do I know much about the version 2 programming.

@ ryan, are you programing it correctly? Plug in battery, wait 2 second and flip the selector to full auto and pull the trigger once. Then after that you'll hear the beeps for programing. Read over the instruction manual for programing and trouble shooting. But it does sound like your selector plate is not in the correct position. If you have another selector plate, swap it and try again. Also try moving the safety lever is a half position (between fire position) and see if that works. If it does, then it's your selector plate.

Good call HKGhost. I remember having that issue with my m4 because of a mechbox/receiver fitment issue. Was only out a couple millimeters but prevented proper firing.

I forgot one more thing, check the cutoff lever. If the lever is not raising high enough to engage the cutoff trigger switch, you won't get semi fire but only full auto. Either replace the cutoff lever or bend it so it raises higher when the sector gear engage it.

@ coachster, yea I've see this issue a lot with cheaper gearboxes. It can make you go nuts when it's just off by millimeters.

I'll try them all out again on this weekend. But first off, it doesn't even start the program mode when I plugged the battery on Safe nor I never programmed it.

@HKGhost, if I send you my gun, can you fix it? I assume you're from Airsoft Parts Canada.

Give it a try and see what you can do, it all fails, then yes you can send me the gearbox to look at. My only concern is the actual mosfet and if it's damaged or not. I won't be able to fix it if it is. Also look at the ribbon cable to confirm there's no damage to any of the wires. That could also cause your issues. Let me know now it goes and PM me.

I just shredded my wires that lead to the motor on my 1st gen ascu and I need to know what's the best way to fix that?

You can splice in any low resistance wires to the motor. I highly recommend soldering(avoid cold joints) them instead of just twisting and taping.

Also avoid any solid core wires.

Getting frustrated by another of these. This will be 3 out of 10 or 12 installs. That is too high a rate of failure!

This one seems to have no active braking. It fires once, over rotates and double beeps and shuts down. I have already changed the data cable once. I tried it again with a anti-reversal latch installed. It just over-rotates and shuts down with the thing locked in a half cycle.

Checked the cutoff lever (it is brand new, as is the sector gear) and it moves the ASCU switch far to the top.

Does anyone know what is happening here?

Hello,

I have problem with my ASCU2. Everything is done according ASCU manual.
I think, I have problem with gear timing, my air nozzle does not stop in normal position - backward, it stops in middle position (nor back or forward) and AEG observes lost of FPS. With stock parts I have no problem. As i know, after semi shoot, nozzle must be in back position.

this is video of sector gears cycling by my hand.
Movie.wmv - YouTube

As you can see on video, I think cutoff lever activates sensor earlier, breaks circuit and nozzle stays in wrong position.

Is any suggestions?
thank you

the cutoff lever appears to actuate normally. the sector gear is in the proper position when the cutoff moves and resets. you are using the proper tappet return spring?

can you take a video of it with the upper receiver off?

This is email from airsoftsystems support, replay about my problem.
But I have g&p m180 motor, which is stronger than systema magnum.
also, I tried with ARL, but without success.

coachster
I am using stock tapet plate and spring. I will assemble AEG and post video again. Thank you for replay.

At first, I thought it was slight over spin from a lower torque motor but since you have the m180 it's hard to say now.

I use the G&P m170 with good results in my M4 but in the MP5 I am using a stock JG high torque motor without issue as well.

I'm at a loss as to your compression issues. You could possibly contact Jugglez for any insight.

Very strange, I am one man in the world, who have this type of problem with ASCU. Google says nothing :)
I will drop it in trash and will live calm :D
I am tired from assembling/disassembling gearbox many times.

coachster
Thank you for attention