iPhone 3G sleep/mute/volume button issues

[craig1410]

Hi,

I've just replaced the flex cable which links the volume, mute, lock buttons and headphone jack hoping that it would fix a problem which has developed on my daughter's iPhone 3G but it hasn't.

The issue is that the mute switch when active also causes the red slider to come up as if the lock button was pressed. Also, the volume buttons have the same effect and cause the phone to lock (as in go to sleep as if lock/sleep button was pressed) when pressed. Volume can be controlled from the sounds applet in settings but obviously this isn't as handy as having the mute button and volume buttons. The phone is on 4.2.1 and is not jailbroken.

I've tried several restores including a couple of DFU restores and I get the same result. I'm confident I've assembled the phone correctly as I'm an experienced electronics engineer and have done this sort of thing many times.

I'm wondering if the connector (number 4 I think) which the flex attaches to may have some bad solder joints. Perhaps a bad earth connection and so the buttons are interacting due to floating voltage levels.

Anyone had this issue and found a solution? Any good workarounds available? Or jailbreak programs to counteract this issue?

Many thanks,
Craig.

 

[greenchiliman]

I'm guessing you are out of warranty? Really, there is no way you are going to be able to fix a hardware issue through software fixes.

Maybe schedule a genius bar appt and see what your cost options are.

 

[craig1410]

Most likely it is the connector, what we do to address the issue is pull the board back out and heat the area with a heat gun, and than clean it with a brush and some cleaner than reheat it. Also check under a microscope or magnifying glass to see if all the connections are straight and clean. Most likely it is the connector though

Hi, I think you're right I was hoping someone would confirm this diagnosis as it gives me some confidence that it may be worth a try reflowing the connector. I'm actually a military standard qualified solderer and have experience soldering very fine pitch quad flat packs so might be able to do this. Trouble is I don't have access to the equipment these days... I do have liquid flux and a fine iron and a magnifying glass which might be enough. Wish me luck!

Thanks,
Craig.

 

[craig1410]

Hi again,

I just had a look at Conn 5 using a magnifying glass and it looks okay. However the group of 4 SMC components between conn 5 and conn 6 are in very bad shape due to corrosion. Only one component still exists at all with the others missing. They are either caps or resistors but I can't tell which. Anyone got any idea what these components are?

One end of all 4 components appear to connect to the ground plane which makes me think they might be caps. Either that or they are pull down resistors.

Any very high res pictures of this part of the board?

Thanks,
Craig.

 

[craig1410]

Hi,

Sorry for the triple post but after my last post I didn't want anyone to waste any time looking for the information I requested, because.....

I've fixed it!!!

It turned out to be the corrosion between the pads of the 4 components I mentioned in my last post which was presumably conducting sufficiently to trigger spurious signals. I cleaned this away with a combination of isopropyl alcohol and some light cleaning with a fibreglass tipped pencil and at one point the point of a scalpel very carefully to move one particularly stubborn piece of material. It actually looked like solder bridged between the contacts but very porous solder as if it was caused by splatter. I presume this is just the result of solder corrosion making it swell up and spread out.

I didn't have to replace the components which I now presume must have been capacitors, perhaps part of a de-bounce circuit. Certainly I would expect capacitors to decompose more so than resistors so this would make sense. If the were pull-up or pull-down resistors then I doubt the circuit would still work without them and yet all the buttons now work correctly. I'm glass because these are really really small components even at 10x magnification and would be a nightmare to replace (probably impossible in honesty) without professional equipment.

I hope this post is of use to other people who have this problem. To help the search engines find this post I'm just going to put in a few of the search terms I was using when trying to find someone with similar issues.

Search terms below:
iphone 3g corroded components
iphone 3g sleep mute volume button problems
iphone 3g lock silent volume button problems
iphone 3g connector 5

Thanks,
Craig.