G&G MP5 stuck on full auto

[Mad Rag]

so after a good day of pew towards the end my gun decides to get stuck on full auto with no trigger movement had to remove the bat to turn off. any suggestions? 

 

[BigStew]

selector plate probably stuck. is the selector switch moving? 

[Mad Rag]

11 minutes ago, BigStew said:

selector plate probably stuck. is the selector switch moving? 

Yup but not much resistance if you know what I mean 

 

[Iceni]

1 hour ago, Mad Rag said:

full auto with no trigger movement

You mean it's on full auto all the time when you pull the trigger, Even in safe.

Or

 

It's on full auto in the semi and auto positions, but safe is still safe.

Or

You have to pull the battery to stop it shooting.


3 different problems.

The first one is probably the selector plate.

The second one is probably a snapped COL

The third is a Fused/Stuck contact, Burnt out mosfet, Or snapped dolly return spring. Since you had to pull the battery to get it to stop I would put money on one of these been the fault. We will need more information about the gun, It's model, Batteries used,  age, and what your level of tech knowledge is.

If it's an ETU model chances are you will need a new ETU. It's not uncommon for the generation 1 G&G's to develop faults like this. If it's a standard contact model then the repair should be pretty cheap <£10 If it's the ETU >£50. + the time to fix it.

If you are not confident at the opening and repairing a gearbox now is the time to send the gun out to a tech.

[Mad Rag]

6 minutes ago, Iceni said:

 

3rd one had to pull the bat to stop shooting. Plug back in and shots right away 

[Iceni]

Yeah it's going to need electrical parts then.

If it's an ETU model expect to pay £50 just for the ETU + tech fees if you can't fit it yourself.

If it's the cheaper standard model chances are the fix will also be cheap and easy. That will totally depend on your level of skill as to what you can save.

If the gun is in warranty... Send it back. ETU's are known for the faults.

[Mad Rag]

not sure if you can tell the model from the picture I'm not sure. Tech level is well probs non existent lol but if there's YouTube vids and guide I think I may manage 

8 minutes ago, Iceni said:

Yeah it's going to need electrical parts then.

If it's an ETU model expect to pay £50 just for the ETU + tech fees if you can't fit it yourself.

If it's the cheaper standard model chances are the fix will also be cheap and easy. That will totally depend on your level of skill as to what you can save.

If the gun is in warranty... Send it back. ETU's are known for the faults.

 

It's not under warranty either 

[Iceni]

No, you won't manage with 0 tech knowledge diagnosing electrical faults.

Pay and send it out if it's not in warranty.

That model looks like the GT advanced TGM A4. It's a £270 gun. It's not worth messing up by trying to fix it yourself.

It's not uncommon for the ETU to break in then, and it will be covered if you still have the warranty. The gun looks to be pretty new and G&G usually offer a 12month warranty.

 

[Asomodai]

The Mp5 is one of the hardest popular RIF's take take apart. Get a professional, I am pretty handy and I gave up just trying to take the outer barrel section apart. 

[Mad Rag]

@Iceni thanks for your advise, what would be the cheapest option for me then do you think.

@Asomodai thanks, im handy too but im thinking this is a rather techie issue 

 

[BigStew]

It's not that difficult to take apart. Two body pins and the mag release hold the upper body and stock on and the the gear box is held in by the selector switch which is held in place by a grub screw in the right hand side selector switch I think then two screws in the mag well.

[Mad Rag]

5 minutes ago, BigStew said:

It's not that difficult to take apart. Two body pins and the mag release hold the upper body and stock on and the the gear box is held in by the selector switch which is held in place by a grub screw in the right hand side selector switch I think then two screws in the mag well.

so im able to stripe down and take out the gearbox trigger ect i can get that far just the electrical side. but what is the etu

[BigStew]

20 minutes ago, Mad Rag said:

so im able to stripe down and take out the gearbox trigger ect i can get that far just the electrical side. but what is the etu

Unless you can confirm the model it might not have a etu.

[Mad Rag]

@BigStew im not sure my slef but @Iceni thinks it could be GT advanced TGM A4

[BigStew]

13 minutes ago, Mad Rag said:

@BigStew im not sure my slef but @Iceni thinks it could be GT advanced TGM A4

Does it have blow back ie did the ejection port cover move when firing?

[Mad Rag]

@BigStew yes it does. also has the handle thing you pull back and that opens the ejection port too (woo im starting to learn lol)

 

 

[BigStew]

Ok then this is probably what the gear box looks like https://www.guay2.com/en/product/detail-1903 etu is internal you need a tech. If it's new take it back under warranty.

[Mad Rag]

1 minute ago, BigStew said:

Ok then this is probably what the gear box looks like https://www.guay2.com/en/product/detail-1903 etu is internal you need a tech. If it's new take it back under warranty.

 

looks about right i think. ill have a look at it tonight when i get home. is it an easy/cheap fix. 

 

[BigStew]

Not a clue I am afraid I know mechanical not electronics but a tech is going to be at least 20 quid an hour. 

[Mad Rag]

Ok so weird thing is it now fires completely fine  it's so weird 

@BigStew

[Shizbazki]

I had the same gun G&G MP5A5, it was part of the TGM range of MP5s they made and it did not come with an ETU built in but a standard trigger trolley as per normal V2 gearboxes.

 

Do you know if it has an ETU? If you have stated it that suddenly started working ok then the chances are that you DO NOT have an ETU, mine did the same a while ago and all i did was give it a whack on the side so that the trigger trolley disengaged.

 

You might find this video of mine interesting where i do strip the gun down to the gearbox.

 

 

[Mad Rag]

52 minutes ago, Shizbazki said:

I had the same gun G&G MP5A5, it was part of the TGM range of MP5s they made and it did not come with an ETU built in but a standard trigger trolley as per normal V2 gearboxes.

 

Do you know if it has an ETU? If you have stated it that suddenly started working ok then the chances are that you DO NOT have an ETU, mine did the same a while ago and all i did was give it a whack on the side so that the trigger trolley disengaged.

 

You might find this video of mine interesting where i do strip the gun down to the gearbox.

 

 

Goes this show if it has one or not ? I'm.not sure whatvi looking for. Bit yeah it's working like nothing ever happend 

[Shizbazki]

Nah the ETU is all hidden inside the gearbox.

 

Basically the only way you will really know is if you take the gearbox out of the lower receiver and look inside it then. My guess (and its only a  guess) is that you dont have the ETU.

 

Unless you know the feeling of squishy trigger compared to clicky micro switch you won't know the difference.

 

The trigger unit is the bit in red:

https://www.patrolbase.co.uk/g-and-g-etu-electronic-trigger-unit

 

A normal V2 gearbox trigger unit looks like this:

https://www.patrolbase.co.uk/keen-sharp-switch-set-and-wiring-v2-front

 

[Mad Rag]

1 hour ago, Shizbazki said:

Nah the ETU is all hidden inside the gearbox.

 

Basically the only way you will really know is if you take the gearbox out of the lower receiver and look inside it then. My guess (and its only a  guess) is that you dont have the ETU.

 

Unless you know the feeling of squishy trigger compared to clicky micro switch you won't know the difference.

 

The trigger unit is the bit in red:

https://www.patrolbase.co.uk/g-and-g-etu-electronic-trigger-unit

 

A normal V2 gearbox trigger unit looks like this:

https://www.patrolbase.co.uk/keen-sharp-switch-set-and-wiring-v2-front

 

I would say more switch than squishy trigger might be wrong though. I spoke to a tech and he thinks possibly carbon on the trigger contacts but not sure. 

[Mad Rag]

so i did some pew pew last night and gun seemed to work fine with no issues. i think i need a new fire selector and it feels very warn and wont really stay in position.