Gun Fault Questions. Help needed please.

[jay83]

Hello you lot, hope you all had a great weekend. Im currently dying from the weekend gone. Need to get fit again!!!!

My G&G Top tech is only 3 months old. The bloody thing fires amazing but just recently last two outings, it starts the day perfect about half way through the full auto stays on for a second after i finish firing and the semi fires in bursts. Its really annoying. I would send it back but the Mrs through out the box which contained the receipt!!!

Why would the gun be doing this?

Simple fix?

Any help would be great guys

Many thanks

 

[Qlimax]

What Gen is it Jay

 

[jay83]

Newest Gen with Mosfet

 

[Qlimax]

Have you checked you have by mistake programmed the FET then mate my mate had that problem and so did I just turned out the FET had been programmed that was it

 

[jay83]

Could be, im not very technical. Only thing is it starts the day ok, they goes bad?

 

[Qlimax]

Have a nosey through the manual mate but that happened to me just the FET had programmed

 

[Lozart]

I don't think the G&G mosfet is programmable is it?

It sounds like the sort of behaviour you would expect from a sticky trigger contact but that shouldn't actually happen with a mosfet'd gun unles the mosfet is goosed. What battery are you running it on?

 

[jay83]

7.4 Lipo mate. Its really annoying me. strange it only does it half the day and starts the day well

 

[Lozart]

Is there any way of bypassing the Mosfet? I seem to remember hearing tales of the Mosfet on the G&Gs burning out

In fact: http://www.airsoft-forums.co.uk/index.php/topic/20546-g-g-top-tech-gen-3-owners-problems-with-mosfets/

 

[dex]

It could be the MOSFET - possibly overheating? - may explain why it starts off ok.

The blokes at Pro Airsoft were saying that they'd had a number back with blown mosfets and that another large retailer (cant remember which one they said, possibly Zero One) had got a ton of mosfets shipped from G&G to replace faulty ones.

Pro Airsoft are in the process of developing a drop in replacement fet unit.

In any case, I have a Gen 3 running on 9.9v life batteries, seems to be running OK so far after 2 skirmishes (I fire semi auto most of the time). Time will tell I suppose.

 

[Ian_Gere]

It does sound like the active braking function of the MOSFET is failing, but I didn't think 7.4V was enough to make selected single shot fire as full-auto. Maybe the gearbox is designed differently to work with the FET?

 

[Unrustle_Thine_Jimmies]

G&G rifles did used to have a problem with the cutoff lever sticking and leaving the gun firing,but that was apparently 'solved'-Maybe through some sort of manufacturing defect,it reared it's ugly head again?

G&G mosfets,according to some people are made to only 'work' on 25c lipos max and apparently burn out at anything larger(Which means it's a joke of a mosfet then) Maybe if shat itself after higher discharge was used?

 

[Ian_Gere]

^^Well yeah, as far as i understand it, active breaking involves dumping current into a convenient resistor, so a higher discharge rate could burn it out, if it were made to tight tolerances.

 

[jay83]

Cheers guys, i went a bit homer simpson with all that techno talk.

Its bloody annoying you pay top money for a good gun and this happens, everyone is always saying G&G are up there with TM but this only proves me that what i aways say is true. TM is the only decent make if just want a gun and dont like doing anything to them.

The actual gun when firing is lovely but after 3 months im getting this hassle already. annoying.

I shall prob take it to a gun tech soon

 

[Unrustle_Thine_Jimmies]

That's kind of the reason I'm giving up on 'top money' guns,you're paying for a brand name and externals essentially. Internal wise most 'top tier' guns are pretty poor compared to some 'cheap' brands,the only difference is that the high end guns are assembled well internally,while materials and part quality are often shit compared to the cheap ones. I'd prefer just to get a cheap gun and give it a light tune up,or buy a cheap ACM gearbox,tune that up,buy a used higher end gun body that's been beat to shit and drop the tuned GB in.

Airsoft guns are like the Japanese tuner cars-Yes,some work well with no mods at all,but most need some work to be reliable.

 

[Lozart]

Cheers guys, i went a bit homer simpson with all that techno talk.

Its bloody annoying you pay top money for a good gun and this happens, everyone is always saying G&G are up there with TM but this only proves me that what i aways say is true. TM is the only decent make if just want a gun and dont like doing anything to them.

The actual gun when firing is lovely but after 3 months im getting this hassle already. annoying.

I shall prob take it to a gun tech soon

That's kind of the reason I'm giving up on 'top money' guns,you're paying for a brand name and externals essentially. Internal wise most 'top tier' guns are pretty poor compared to some 'cheap' brands,the only difference is that the high end guns are assembled well internally,while materials and part quality are often sh*t compared to the cheap ones. I'd prefer just to get a cheap gun and give it a light tune up,or buy a cheap ACM gearbox,tune that up,buy a used higher end gun body that's been beat to sh*t and drop the tuned GB in.

Airsoft guns are like the Japanese tuner cars-Yes,some work well with no mods at all,but most need some work to be reliable.

Even Rolls Royces go wrong sometimes. Buying a more expensive brand SHOULD give you a higher chance of getting a better made/designed product but as you have become aware it's not a guarantee. The thing to look at though is the overall throughput versus the failure rate when judging a brand. If G&G for example are having an issue with some of their MOSFET units (I assume that the rest of the gun isn't falling apart as well) then obviously they have a QA problem with that specific part. The value in buying a decent brand is just as much in the after sales and how quickly they move to rectify the fault as it is in the actual product itself.

Buying cheap and then spending time, effort and money to get to a point where the higher end products always are isn't always cost effective. It depends on how highly you value your time and whether or not airsoft teching is your thing. Having bought an old TM M4A1 and spent the time and effort (and money) to get it to where it is now pretty much as good as a gun I could have bought straight off the bat with the same total budget has taught me one thing - do it because you WANT to not because you think it'll be a cheaper way of getting a good gun.

 

[dex]

Buying cheap and then spending time, effort and money to get to a point where the higher end products always are isn't always cost effective. It depends on how highly you value your time and whether or not airsoft teching is your thing. Having bought an old TM M4A1 and spent the time and effort (and money) to get it to where it is now pretty much as good as a gun I could have bought straight off the bat with the same total budget has taught me one thing - do it because you WANT to not because you think it'll be a cheaper way of getting a good gun.

This. I bought a G&G top tech as a gun that I wouldn't mess around with that would work well out of the box. My "project" AEG is built from parts worth 2 or 3 times as much as the stock G&G and is a finicky beast. When it works its works its awesome, then I'll go mod something else and screw it all up

 

[Ian_Gere]

I'd just like to chime in here with this: TM AK gearboxes are bollocks and if you want a plastic gun you can get one cheaper and better inside and out from ICS. Yeah, the hop units are good, but no better than CYMA and the CYMA rubber is better for accuracy. I'm with UTJ on this: top price guns are at best ok internally - as much as I might plan to leave a gun alone, the minute I sense it under performing whatever my chosen FPS limit ought to give me, the niggle in the back of my mind starts... "if I just put X in it" and it wont shut up until I do. But once the thing is opened up and I see the cheese bushings and macaroni nozzle, that's a new niggle... crack the box and find... a whole raft of crap i'll not be happy with until it's sorted. Well, if i'm going to do that anyway, no point spending a fortune to begin with.