iPhone 4 mic not working during call

"hi, had same problem with my iPhone 4 that i bought from eBay.

tried everything that did not involve opening the phone but nothing worked, just could not understand it... So after reading what jamespribil said i gave it a shot with isopropyl alcohol, gave it a nice bath for about 2 hours and cleaned it from time to time with a touth brush, to my amazement it worked... crazy but it did.

When i opened the cover on the logicboard, one thing i noticed was that there was only plastic protectors under one cover and not 2 like its suppose to be, do not know if that was what caused the problem but just glad i came here, as i was not going to do that...

Just wanted to share that it worked for me, but do not open logicboards if you do ot know what you are doing, thanks..."

"Hello,

You have almost done everything possible, but try doing a restore in itunes, might be your only chance if you have tried everything else. Unless of course someone else thinks of another solution."

"For those still referring to this post, I can suggest one more approach.

I will label everything on the faulty phone as ""problem …""

IF restoring the software does not solve this issue, and software problem is excluded, I would try the following:

1/ Transfer ""problem board"" to known good casing.

2/ If problem is solved, then transfer ""problem dock connector"" to known good casing.

2/a/ If problem reappears, replace the ""problem dock connector."" This should solve it.

2/b/ If problem does not reappear, you might want to look at the upper mic on the ""problem casing.""

The upper mic is part of the iPhone 4 Power and Sensor Cable.

First try cleaning the connectors of that flat cable, and the connector on the board where this flat cable attaches. Use a proper solvent such as ""contact spray"" or 90%+ isopropyl alcohol. Just drop a tiny amount on a clean toothbrush and lightly brush both the cable connector and the board connector. If this does not help, try replacing the whole connector.

Additional note: on the outer frame of the phone, next to the headphones jack hole, there is a tiny ""pin"" hole. Make sure it is not obstructed, as this could cause issues with sound => although it should not completely suppress it."

"Your phone is faulty, it has a manufacturing defect that was there when you purchased the Phone. This is a hardware fault and will only get worse over time.

Request a Refund or replacement ASAP even if the phone is out of warranty. As the You Tube video Suggests a defective soldering joint comes loose over time, sometimes within warranty sometimes not.

Apple should offer immediate replacements for all users affected by this issue where the phone has been looked after as per manufacturers recommendations and not neglected by the end user."

its not any of the above. its the software you are currently running. i have the same problem on my iphone 4s theres nothing you can do about it until apple decide to release the 6.1.4 update. So no need to worry guys. its all good in the hood. chin up.