DFGT doesn't steer anymore

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Nuschel01

Nuschel01

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Hey,

I have used my DFGT for I think 3 or 4 years now and never had an issue with it despite the terrible pedals tho. So now I was enjoying some drifts on Midway when I really had to catch the car by steering from full left to full right 5 times. After that the steering became somehow squishy and the wheel smelt burnt. I unplugged it and opened it, then I saw that the FF-motor was covered in black "dust" plus it was a little hot. I started googling a bit and found out that the problem could be the steering sensor, but this little wheel between the sensors is not broken or dirty so I guess that's not the problem. There also is no cable unplugged and all the buttons work perfectly. The only thing is that the wheel doesn't send it's steering-information to the game and the GT-logo is not enlighted.

Has anyone of you a suggestion for what I can check or replace to make it work again?
 
Nuschel01
Hey,

I have used my DFGT for I think 3 or 4 years now and never had an issue with it despite the terrible pedals tho. So now I was enjoying some drifts on Midway when I really had to catch the car by steering from full left to full right 5 times. After that the steering became somehow squishy and the wheel smelt burnt. I unplugged it and opened it, then I saw that the FF-motor was covered in black "dust" plus it was a little hot. I started googling a bit and found out that the problem could be the steering sensor, but this little wheel between the sensors is not broken or dirty so I guess that's not the problem. There also is no cable unplugged and all the buttons work perfectly. The only thing is that the wheel doesn't send it's steering-information to the game and the GT-logo is not enlighted.

Has anyone of you a suggestion for what I can check or replace to make it work again?
Click to expand...
"FF-motor was covered in black "dust"-this is from the motor brushes,in the motor jacket has small holes see through them inside with flashlight two little metal plates with black material between them and motor axle,if this material missing and the plates touch motor axle directly you have to change the el.motor
 
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@super_gt, what exactly do you mean? I made some photos, maybe you can tell me by them if the motor is ok or not.
 

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So if you plug it in, does the wheel turn by itself at all?

If it doesn't, it could be that carbon dust from the motor brushes has accumulated between gaps in the commutator which has created a short circuit, in turn that has most likely blown the MOSFETs that form the H-bridge motor driver circuit.

If this is the case, the good news is:
- The motor is probably fine, it just needs cleaning.
- The MOSFET ICs are quite easy to source, I think.
- The rest of the wheel should be fine. The MOSFETs are where the low voltage signals from the all-important microcontroller meet the high voltage motor, so when they blow because the motor is shorted and briefly drawing several amps at 24V, the microcontroller should have escaped any serious damage. I say 'should' because, well, maybe it is damaged... It's impossible to say until you fix the motor and replace the MOSFETs.

The bad news:
- If you have no experience when it comes to desoldering SMD components, you're going to struggle to replace the MOSFETs yourself. It can be done with a soldering iron (of suitable power and tip size: not too much heat and a small tip is best) and some desolder braid but so much can go wrong; you could, for example, accidentally brush a surface mount resistor with hot, flux and solder-saturated braid and lift it off the board without even noticing.
- You need to disassemble the motor to fix it. You'll also probably want a multimeter to test for a short before you take it apart, but you can get dirt cheap ones so that's not a big deal.
- There are at least two revisions of the old G27s, one uses one model of MOSFET and the other uses a different type. The DFGT has the same MOSFETs in it, but I've only been able to find the older type when I've looked for replacements for my G27. I think they're 100% interchangeable though as the datasheet specs are a very close match, so this may not be a big deal.

If you know anyone good with electronics, none of the bad points are as bad as they seem, it should be quite trivial for someone with the right equipment and experience to replace the two MOSFETs and maybe the TVS diode (that may have died from the sustained voltage generated by the motor from twirling the wheel around as much as you did, but @eKretz knows a lot more about what the TVS diode is for and what happens if it blows than I do). I wouldn't want to do such a job with a cheap firestarter soldering iron, though...

When I'm at my PC tomorrow I'll try to remember to post a guide that details how to test and clean the motor (unless someone beats me to it), if I forget send me a PM or mention me here and I'll get to it.

If the wheel does turn and calibrates itself as normal but doesn't send steering data to the game... Contact Logitech. It might be worth doing that anyway, they're very, very good when it comes to support.
 
Hmm, first things first, does the OP have any experience at all with electronics? If no, I would say we guide him through at least enough to determine a ballpark area where the fault lies, then we can determine if he will be capable of fixing it or not. Surface mount soldering isn't something I'd recommend the uninitiated jump into without someone experienced being present if OP has no experience whatsoever, which is what it's sounding like.
 
Thanks you two for the replies.
The wheel doesn't calibrate itself when I plug it in. Sadly english is not my main language so I only understood like half of what you said because of those many specific words.
My experience with electronics is very small, so I guess I'll need a guide then :D
 
Ok, third time lucky... My phone keeps deleting my reply.

Here's the guide I mentioned, it's in English (sorry!) and it's for the G25/27 but the part about the motor is the same for the DFGT:

https://www.dropbox.com/s/nxs2imi2xh3j8mj/logitech_repair.pdf?dl=0

But, as @eKretz says, it's a very, very bad idea to try surface-mount soldering on something expensive with no experience.

What I would do if I were you:
- Call Logitech and explain what you said in the first post, even if you bought it second-hand and it's out of warranty. I've heard a number of stories where Logitech's customer support has gone beyond what most people would expect from such a company, I remember reading one post where the customer was asked to just email them a photo of their broken G27 with all the cables cut and they'd send out a new one, even though the warranty had expired.

- If that doesn't work, try to find an electronics repair shop, Hackspace or other electronics hobby club near you, get in touch and explain that your wheel is broken, you know what needs to be done to fix it but you don't have the experience or tools for SMD soldering. If someone came to my Hackspace and said the same I'd gladly help, it's a pretty easy job for someone who knows what they're doing.

- If that doesn't work, try listing it on Ebay. Make it clear what the problem is, include the link to the guide and basically make it very obvious that you're not an idiot and you know it's an easy fix for the kind of person who buys broken stuff on Ebay to fix for resale and set the starting price quite high (but not as high as a used, functional wheel, of course). It would be better to get, say, 60% of the price of a new wheel back and buy a new one than break your wheel even more by attempting to fix it yourself.

- Failing all that, I guess try to fix it yourself. If you want to do that then we will help you find everything you need, but I really, really recommend trying every other option first.
 
Nuschel01
Hey,

I have used my DFGT for I think 3 or 4 years now and never had an issue with it despite the terrible pedals tho. So now I was enjoying some drifts on Midway when I really had to catch the car by steering from full left to full right 5 times. After that the steering became somehow squishy and the wheel smelt burnt. I unplugged it and opened it, then I saw that the FF-motor was covered in black "dust" plus it was a little hot. I started googling a bit and found out that the problem could be the steering sensor, but this little wheel between the sensors is not broken or dirty so I guess that's not the problem. There also is no cable unplugged and all the buttons work perfectly. The only thing is that the wheel doesn't send it's steering-information to the game and the GT-logo is not enlighted.

Has anyone of you a suggestion for what I can check or replace to make it work again?
Click to expand...

Sounds like a sensor problem rather than a motor problem. The wheel is able to send steering information to the PS3 even when the power cable is unplugged (mine has accidentally unplugged several times, and I do lose force feedback, but I never lose steering), so an engine that stops working shouldn't mean that the steering is lost.
 
yeah i even unplugged the engine by purpose when driving the X201*.

The weird thing is the motor lost power and the steering became squishy and it smelled like hot metal.
 

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