Fixing the FP2 headphone socket

[conrad]

EDIT: see second and third followups for substantial improvement.

Has anyone made any progress on improving their experience with the FP2 headphone socket? As reported in many other threads, it seems unusually sensitive to movement of the headphone plug. My experience is that, in a loose pocket, any movement will tend to disconnect one channel (mainly the left, which is the tip of the stereo connector). In experiments, the actual movement that causes this seems to be from pressing the cable end of the headphone plug either towards the camera or towards the screen. The issue turns up in the following threads, among others:

• Not sure if audio jack or headphones is the problem
• FP2 Repair of headphone socket
• Headphone slack
• Headphone connector can’t hold on to Headphone Jack properly

… people have experienced it with all kinds of plugs, and tried replacing the top module, only for the problem to return, so it seems likely there’s a design flaw in the headphone socket. I’m interested in whether anyone has come up with a working hack to help the situation?

I’ve tried two approaches, and they’ve helped a little lot but not completely solved the problem. If I’d analysed a little more before taking action, I might have saved myself some time, but in case anyone else is interested, I’ll document what I’ve tried in the next two replies here.

[conrad]

My first approach was based on the observation that the new slim case prevents the headphone plug from being inserted to its maximum depth. Others have noted that when you plug the headphone in while the phone is in the slim case, the slightest movement will cause the plug to fall out about half a millimetre, after which point the connection becomes very unstable. If you remove the slim case and plug the headphones in, this is not an issue. The cause is that the scalloped area around the socket is neither wide nor deep enough to allow you to fully seat your headphone plug (I note that some plugs have longer shafts than others, but this seems to affect all of the plugs I’ve tested).

It should go without saying that any modification to your phone will void your warranty.

On the basis of this I tried using a large drill bit to deepen and widen the socket area on my slim case, holding and turning it by hand. This is an ugly modification to make, as it scrapes away at the plastic and doesn’t leave a nice finish. You might get better results using a dremel type device and a sanding bit instead.

This helped with one very compact headphone plug, but not others: I thought that enlarging the socket area enough for the metal skirt at the base of the headphone plug to be fully inserted into the socket area would be enough, but having done that, the plastic body of the headphone plug is now flush against the slim case and it’s still at that almost-fully-inserted position from which it falls back out if knocked.

So: this mod is ugly and won’t help unless your headphone plug’s body is very narrow. It may also not help if your headphone plug’s metal shaft is a fraction of a millimetre short.

[conrad]

EDIT: see post below after reading this — this approach actually does seem to have a substantial positive effect, but I missed out one of the contacts in my first attempt.

My second approach was based on the assumption that the sprung metal connectors in my headphone socket weren’t gripping the headphone plug tightly enough. I thought perhaps I could lever them out a little for a tighter grip.

This has helped: I used to lose both channels randomly, but now the socket appears to have a steel grip on the right channel both channels — however I still lose left channel connectivity almost all the time.

It should go without saying that any modification to your phone will void your warranty.

So, I took out my phone’s top module (iFixit’s Fairphone 2 Teardown is an excellent resource, but note also the video in step 4 of their Display Assembly Replacement video — gave me much more confidence taking the display off). The top module is easily dismantled with a Torx screwdriver; after opening it, you can disconnect the PCB by gently levering out the ribbon connector.

At this point a problem becomes apparent: there’s no external access to some of the contacts in the headphone socket, particularly the two which grip the middle of the plug, carrying the right channel. I was able to lever in both the tip (left) contact and the base (ground) contact from outside the socket, but was at a loss with the remaining pair. Eventually (very frustrated by audio disconnects) I decided to drill out access holes for them. This was pretty scary, but didn’t go too badly in the end.

This is a tricky modification which requires delicacy and could do all kinds of harm to the parts affected: proceed with care.

Using a 1mm hand drill to create the pilot hole, followed by a 1.5mm drill, I created two holes in the socket to allow access to the middle pair of contacts. I initially marked the hole locations with a spike, but was reluctant to use much pressure so am not sure that that helped. Here’s the part, clamped delicately and wrapped in several layers of tissue, job completed:

The left hole is perfect; I was being very careful on my first try. Got overconfident and on the second try I drilled out of the socket a bit. Just go extremely slowly, apply the bare minimum of pressure, check your work every turn or two of the drill, etc. It is possible that 1mm holes alone would have done the job, but 1.5mm is certainly enough. You can see the two contacts, particularly the one through the right hole, and it’s trivial to stick a sewing needle in to lever them out a bit.

Needle, 1.5mm drill bit, 1mm drill bit, finished part.

As noted above, this has helped a lot, but hasn’t completely solved the problem: all I suffer from now is left channel (tip contact); I may try opening the phone up again to tighten that further, but I think the problem may be insoluble since the tip connector only seems to have a contact on one side some rotational dropout.

Any other suggestions would be most welcome.

[paulakreuzer]

@conrad

people have experienced it with all kinds of plugs, and tried replacing the top module, only for the problem to return,

Interesting theory but I just went through the 4 threads you linked to and found 18 people reporting the issue only 4 of which still reported it after a module replacement and of them 3 tried with the same cheap headphone.

[conrad]

Substantial improvement obtained!

I had a slowly growing sense of “D’OH” as I was writing up my second approach: I realised that the contacts I’d adjusted couldn’t possibly have included a tip connector, and my remaining problems seemed to be with the tip. Of course the phone needs four wires to cope with ground, microphone, left and right channels, and while I’d adjusted four contacts, two were for the same connection, effectively gripping the “neck” of the plug. My previous photos even show where the tip contact is, and like the first pair that I had to drill to get at, it’s inaccessible. Opened things up again, drilled into the back face of the socket to get at the final connector, tightened it up, and had my first dropout-free walk while listening to audio in over a month…

In the above image of the rear of the headphone socket, the large circular hole is part of the original structure of the socket, but the smaller circle connected to it is drilled out with a 1mm drill bit. You can see the tightened tip connector glinting through that smaller circle (actually that’s levered out a little far). The 1mm drill bit is definitely large enough, but the position that I’ve drilled in there is not ideal: if doing it again I’d go 0.5mm further left. As it was, I could see the connector through the hole, but it was a bit of work to get a needle behind it to lever it out/tighten it up.

This isn’t perfect: I still find that one channel or another will just drop if I rotate the plug to the right angle, but once both channels are playing, there are no drop-outs from pushing the plug left/right/forward/backward, and after dropping the phone in my pocket I can walk freely without interrupting the audio.

I’ll report back in a week to say whether the fix survives daily use.

Tips for anyone else trying this:

• Having a compressed air canister is handy, to make sure there’s no plastic dust left in the socket after you’ve finished working.
• Before you start to reassemble, take a careful look at what happens when you insert and remove your headphones a few times, just to see everything looks ok and the contacts appear to connect.
• I sprayed a bit of contact cleaner into the socket before closing things up.
• When reassembling the top section around the PCB before reinstalling it in the phone, I found that of all the metal clips that hold the two halves of its plastic wrapper together, the clips at each end got stuck bent a little outwards and so didn’t grip nicely during reassembly: bending them back in a little before clipping everything together helped.
• I’m now almost certain that you don’t need the 1.5mm drill bit: 1mm should be good for all three holes.

[conrad]

Hi Paula,

Maybe we should try a poll to get better data; writing the report caused me to realise that I had made a stupid mistake and missed the tip contact altogether (see update above) [benefits of trying to explain one’s thought process! ]. I now seem to have obtained a substantial improvement — enough that I’m pretty convinced that the audio dropouts are due to mechanical problems with the headphone socket.

[userr]

Hey,
I have the same problems and my attempt(link in the first porst) was not really working. At that time the dropouts just started to occur.

I like your aproaches Conrad!
Maybe I will try that aswell. But it would be even nicer to get a new socket and replace the old one.

Similar thing:
I bought my first slimcase recently because my old one lost its rubber. And my earphone jack is a bit to big for the new case.

So I have to file the plastic away.
The fact that the case wall is quite thick is a good thing! But the area around the hole should be bigger in diameter.

cheers
Patrick

Fun fact: I own the jack for like 10 years Its from Neutrik and cost I guess 4 €(!) at that time. But all my earphones failing at the cable near the jack. So every time the cable fails I cut it shorter and resolder the jack.

[conrad]

Hah, nice! I’ve been thinking of replacing the plug on my 'phones for a while: currently they’re ¼" with a 3.5mm adapter. What I really want though is a module I can inline to implement pause/play controls.

Ideally I think if you want to make more room for your Neutrik jack, you’ll need something like a Dremel and a lever-controlled drill stand, so you can do the job really precisely. My manual attempt with an 8mm drill bit is ugly. If you’ve got steady hands though, maybe working manually with the Dremel will do. Good luck & let me know how you get on!

[userr]

Yeah I would love buttons for play/pause and even forward/backwards!

Update on the slim case:
I used needle files which was good because the plastic is quite hard. Even 60 - 100 grit sandpaper wrapped around a pen would work nicely.
The contact got a bit better but best thing would be to replace the socket.
Currently I am waiting for an answer from support, if they can disclose some part numbers

[conrad]

Neat work: you’ve persuaded me to have another go at the case!

Here’s a one-week follow-up on my above attempts to “tighten” the headphone socket: it has definitely improved things, insofar as I can now reliably listen to audio on the move, but it’s still finicky: getting into the right stable position to listen continuously is still difficult. It is possible that this is because the jack isn’t seating itself fully in the socket because of the slim case being too thick, so I’ll be trying some more experimentation soon, along with an attempt to replicate @userr’s work. It’s certainly the case that most of my remaining dropouts are from the headphone plug popping out a half millimetre or so.

[conrad]

Follow-up three weeks on: filing away part of the slim case has helped some more, although I think I’ve been a little too cautious so some more work needed. The headphone plug no longer spontaneously pops out of the socket, but the connection still loses the right channel if the plug isn’t rotated (!) to the right angle.

[conrad]

Another note on this: I eventually narrowed the rotational sensitivity (mentioned in my last comment) down to connector failure in the headphone cable after I noticed the headphones starting to misbehave elsewhere. Taking a page from @userr’s book, I replaced my headphone plug with a Neutrik one. Very solid, well-built little thing, and has improved things further. Still getting some pop-out, and some channel loss while walking, so may yet file the case down some more.

[conrad]

Hopefully my final note on this subject: I was picking up a spare case for the 'phone, so ordered a replacement top unit at the same time. This has broken the front camera in certain apps, but appears to have almost completely solved the remaining drop-outs I was getting. Pressure on the headphone plug in one direction still causes loss of one channel, but it’s extremely rare now.

So, in conclusion: my audio issues seem to have been an unfortunate combination of three factors: a bad top unit socket in my phone, the slim case being too thick around the headphone socket, and a failing plug on my headphones. If you’re having problems then test with multiple headphones in multiple devices (including with the case removed from your phone) to narrow down the cause.

[edit: nope, new top unit only lasted a month; not happy]

[gr1mbl3]

Hello!

I’ve had my FP2 for around 2 months and the problem has been here from the beginning. My headphone jacks creates distorted noise when I listen to music. It sounds like when your headphones are broken, but that’s not the case here since I’ve tried with multiple headphones and aux-cables. The problem remains for all of them. It’s worse when I move or move the phone. I have to be absolutely still to listen to music without the noise.

What can I do?

Glad of any help!

[Patrick1]

So I assume you mean listening to archived music such as .mp3/.flac/.ogg files and not FM radio?
Which audio player app are you using, have you tried another?

[conrad]

Grr, spoke too soon. After only a month with the new top unit I’m getting dropouts again. Will be contacting FP support, sigh.

@gr1mbl3 take @Patrick1’s advice and try other software. If it still fails, contact FP support before you’re out of guarantee…

[gr1mbl3]

I’ve been using the Spotify app for music, but it’s a problem anywhere - just having the earphones plugged in creates the noise and any other sound source, like radio or videos etc.

[Patrick1]

So if you are confident that your earphones are in order and may have also tested another pair with the same result maybe support is the only solution left for you.