Ares EFCS fried FET's

[Chris_B]

Hello UKAF members.

I'm currently having issues with an Ares G36C that keeps blowing it's EFCS (Electronic Firing Control System) mosfet board.

It's on its 3rd one now and the problem seems persistent. Upon testing the components on the EFCS circuit board, the FET's (Field effect transistors) keep blowing for no reason at all.

Going back to the beginning; 

Bought this gun as a non-worker boneyard from a UK airsoft retailer (can't remember which one). With the issue of not working when the battery is plugged in, no response, nothing...

Bought a new EFCS circuit board directly from Ares HK, but prior to install, I re-shimmed the gearbox, got a decent piston airseal (new cylinder & O-ring), new nozzle with O-ring and install brushless warhead motor (because Ares EFCS does not have LiPo protection.

Installed the new EFCS PCB, worked for a little while, then the smoke came out... No response yet again... Back to Ares, explain what I did, they were happy enough to send out another EFCS PCB.

While waiting for the 2nd replacement EFCS circuit board, I went over my work inside the gearbox, all is fine; gears are shimmed nicely, and airseal is good. (The gun fired very nicely when I got it working).

Second EFCS PCB turned up, installed, fired just under 500rds, went to clear the gun, fired 2nd shot and again, stopped working and I could smell smoke.... Back to the drawing board.

Things I've gone over and checked;

Battery is a good, been working fine on other guns with MOSFETs installed, even works fine on my G36E that has the same Ares EFCS.

No shorts in the wiring, the wiring comes pre-soldered onto the PCB with a mini tamiya (soldered deans on when I got it) also checked deans polarity is correct.

Checked motor: it's a brand new warhead motor which has in-built fault detection and low voltage cut off. Have wired battery directly to motor and it spins all ok.

It seems that it keeps blowing the same pair of FET's on the circuit board. I've had a quick search online for the same issue and it seems that some people have had the same issue with their Ares amoeba M4's that are blowing their FET's.

I just can't understand why mine has blown 3 in one go... Are these Ares EFCS mosfets complete trash? (Obviously yes...)

I've emailed Ares technical help and still awaiting a response.

Image attached and blown FET's circled for reference.

TIA 

Chris 

View attachment 97760

 

[mightyjebus]

could be the brushless motor. Chances are Ares used a cheap Mosfet that isn't designed for brushless motors. there's some interesting data here on mosfets and brushless motors.

https://www.electronicspecifier.com/industries/industrial/how-to-drive-bldc-motors-effectively-with-mosfet-tech

 

[Chris_B]

I have to add that I have another Ares G36E that has the same EFCS MOSFET and a warhead motor installed on it too which is still working fine. 

I can't see how a brushless motor that draws less current than a brushed can fry power transistors... These are rated for 30V D.C. at  109Amps.

Chris

 

[Pseudotectonic]

Looking at the solder joints I think it's sub-par quality and the top FET in your circled appears to have a cold solder joint on the bottom leg (meaning poor contact)

So if it's a repeated issue I would switch to another brand of MOSFET

 

[Pseudotectonic]

Oh wait hang on, is the back of the board touching the gearbox? If there's anything behind wouldn't that short things out? Does it need a spacer or something?

 

[concretesnail]

You could try and give the board a brush of conformal coating. If could be that part of the gear box is missshaped and creating a shorting a part.

 

[Chris_B]

Oh wait hang on, is the back of the board touching the gearbox? If there's anything behind wouldn't that short things out? Does it need a spacer or something?

There is a silicone insulating film in the shape of the PCB board, hard to see but it's there, (can see it covering the middle bearing)

You could try and give the board a brush of conformal coating. If could be that part of the gear box is missshaped and creating a shorting a part.

Upon further testing, the top two FET's are dead (nothing on the volt meter when in diode test mode). I have another working G36 E.F.C.S. mosfet that I'm taking my tests from.

Looking at the solder joints I think it's sub-par quality and the top FET in your circled appears to have a cold solder joint on the bottom leg (meaning poor contact)

So if it's a repeated issue I would switch to another brand of MOSFET

I had a go at de-soldering the bottom FET and it came off pretty easy.

Think the plan is to purchase some like-for-like (but better quality) FET's. Just need to get a solder rework station.

 

[Chris_B]

UPDATE:

So this is the response from Ares technical help... See what you think;

'Our technician said our gearbox cannot support the brushless motor because of the gear ratio.

Also, the brushless motor doesn't have enough torque to hold the spring causing the voltage rise. Please try to use the factory motor and see if the issue can be solved, thank you.' 

The gearbox configuration is as follows;

• Standard Ares 18:1 gears with magnet 

• Standard Ares piston. (Piston rack chamfered on the edges)

• Standard Ares piston head (with nylon spacers for AoE correction & new O-ring)

• ZCI 4/5 ported stainless cylinder

• Ultimate G36 nozzle w/o-ring 

• Warhead Base 35k brushless motor 

• Guarder M110 spring (1.2J)

• ZCI V3 quick change bearing spring guide 

Also got a response from Luke at Warhead industries;

'Any aeg that has active break that you cannot turn off may have side effects on the Warhead motor.

I know some people have claimed that they have fitted a warhead motor to an ARES however it's not something that I have done as I personally don't think that an ARES can handle it & this email kinda proves my

point, sadly.' 

Luke's response to Ares technical help email to me;

'Basically, they're talking nonsense as an excuse - saying that the brushless motor doesn't have enough torque is absolutely false, I have placed a video on our youtube channel showing a full stroke piston &

18:1 gears pulling an m160 on a 7.4v lipo better than most standard motors pull an m160 on 11.1v's.

I have a very good reason as to why the ARES EFCS keeps dying, but I can't discuss it here.

With an EFCS from ARES you may cause your (may) cause your motors ESC to burn out.

You've already seen the results first hand of which normally wins the battle between the ESC & the EFCS should one product be not up to task, however.'

So it seems that there is an incompatibility issue between Ares E.F.C.S. mosfets and warhead motors, strange as I have another G36E with the exact same gearbox E.F.C.S. unit and an Ares L85A3 with a slightly different E.F.C.S. unit, but this one is programmable using their programmer, and these are still working fine. The only thing that's different with these is I've soldered new 16AWG silicone wiring to the boards.

I think moving forward on this issue; upon researching online for the same issue, other people have had their E.F.C.S. burn out on their Amoeba M4's, G36's etc but on standard motors. But I haven't found evidence of anyone actually finding the root cause or repairing their E.F.C.S. boards, they either buy new ones or their topic thread goes cold.

What I will try and do is source new but better rated N-Channel FET's and replace the burnt out ones and hope the rest of the circuit components are still intact. 

Chris 

 

[andrey]

Hi C! How is the story now, at what point have u arrived?

I have a nice new G36c ares efcs and yesterday stopped working, l assume is from the same issue. Using half day an 11.1v and then a 7.4v for one hour and then the trigger died. 

 

[Leo Greer]

This issue is caused (almost certainly) by that small little microswitch in the top right corner. Looks up how microswitches react to relatively high amperage (compared to what they’re supposed to be used for) and you’ll have your answer.

It’s a design flaw with the EFCS, causing the microswitch to send thousands of electrical pulses through the system, causing heat to build up, causing the chip to fry.

 

[Chris_B]

Hi C! How is the story now, at what point have u arrived?

I have a nice new G36c ares efcs and yesterday stopped working, l assume is from the same issue. Using half day an 11.1v and then a 7.4v for one hour and then the trigger died. 

Hi Andrey,

Yes I did get that the bottom of it, after a bit of bench testing and probing, I found that a 3.3V SMD regulator wasn't getting power directly from the battery, this 3.3V SMD regulator powers the hall sensors for the selector and magnet in the sector gear, and following this back, I had found a blown Schottky diode, with the letters 'SL' printed on it (circled in the picture).

Seems like it's a common fault in these, as two separate EFCS boards had the same one blown.

I ordered some new ones from RS components and it's been running beautifully ever since (touch wood).

I haven't had any experiences with the trigger micro switch failing... I see lots of comments online pointing to this, but a simple continuity test with a DVM can quickly tell you this.

Probably a bit easier for me to diagnose and repair as I'm an electrical techie by trade, but can always offer a hand if anyone experiences the same EFCS failures.

All the best.

Chris 

View attachment 114681

 

[andrey]

Tks for the answer Chris. I have shown my mosfet to a friend of mine (electronic officer) and he told me the same. As inspected mine, exactly the same part failed so l have ordered some spare parts from ebay and will replace it soon. In the meantime l have contacted ares and they will send me 2 MOSFETs for £35 posted. 

For the other users of this platform: l burt mine on a skirmish day, playing 2 hrs with a 11.1v Lipo only semi (was cqb) and when my battery died l have switched to a 7.4v lipo battery and after one more hr, the mosfet died.

View attachment 114686

 

[Chris_B]

Tks for the answer Chris. I have shown my mosfet to a friend of mine (electronic officer) and he told me the same. As inspected mine, exactly the same part failed so l have ordered some spare parts from ebay and will replace it soon. In the meantime l have contacted ares and they will send me 2 MOSFETs for £35 posted. 

For the other users of this platform: l burt mine on a skirmish day, playing 2 hrs with a 11.1v Lipo only semi (was cqb) and when my battery died l have switched to a 7.4v lipo battery and after one more hr, the mosfet died.

View attachment 114686

Ares sent me some replacement EFCS boards but there are two flavours of board design....

My original is the bigger 'L' shaped PCB while the one Ares sent is a more updated version that's rectangular shape but overall it was longer... I had problems fitting the back plate with the dust cover spring/ guide in because the EFCS mosfet overhung the gearbox when it was screwed on.

Let us know how you get on with the repair, as it'll be good to document it to help others that'll stumble across this thread.

I'm sure the Amoeba EFCS has the same PCB schematic so maybe this would be of use with that community.

All the best,

Chris 

 

[andrey]

Mission successful!

I have repaired my mosfet tonight, now the toy is working fine. Was hard to get it replaced, u need magnifiers, a pointy solder gun, good light and steady hands.

View attachment 114784

 

[Sewdhull]

Good news. Do you know why the diode failed?

 

[andrey]

I can only blame the 11.1v Lipo used on only semi (was cqb site). And from now l will use on this toy only 7.4v lipo.

 

[Chris_B]

Mission successful!

I have repaired my mosfet tonight, now the toy is working fine. Was hard to get it replaced, u need magnifiers, a pointy solder gun, good light and steady hands.

View attachment 114784

That's really good to hear @andrey. Might be worth having this post as a sticky thread as it's so common in the Ares EFCS.

When mine failed, I only used 7.4V 2600mAh LiPo. The first replacement mosfet I got from Ares was the updated longer type that you have there @andrey and the back of the EFCS board started smoking and a copper track broke. Don't know why as I put a new insulating pad that came with it behind the EFCS board.

The other two after that had the same issues as you've had, blown Schottky diodes. As I said in my post above, it was a standard gearbox but with a warhead base motor. Time will tell with this but at least we know what to look out for in the future.

But if this keeps happening again and others that read this want to steer clear of the Ares EFCS, it might be worth modifying the gearbox to take a Perun V3 hybrid. 

I've successfully installed a V3 hybrid into the standard Ares G36 non-EFCS gearbox with a bit of milling by the micro switch and it's working perfectly.

Chris

 

[Mathematicus]

Hello from across the pond! I've been researching on these Ares EFCS mosfets for quite a awhile. I don't have an Ares G36, but I do have a UMP by Ares - and they use the exact same mosfets and gearbox. Same issues described in every post. Went through two different mosfets of the L type that fried. Went through two different mosfets of the wider ones that fried almost immediately.

I am having a headache ordering from Ares in HK and I fear using the UMP despite it being my favorite weapon because I'm afraid it'll stick full auto on someone or randomly fail detecting the hall sensor and lets out burst. I'm not great with a solder either.

@Chris_B I've created an account to ask this, but by any chance can you share to us all who may have and/or will experience these issues how to fit the Perun V3 hybrid on the Ares G36/UMP shell? I feel this will save a lot of us a headache.

Thank you all for your insights and work on this.