Technical trouble shooting and rational required. I know that there are endless threads out there on iPhone 4 sound problems but there are not a lot of good answers (none really) and the threads are horribly muddled with tons of user flack of: "My iPhone does this and my iPhone does that". I am attempting to start a clear thread so that people with "this exact problem only" can search and find on the internet hopefully the real possible solutions, if any. Please Do not post unless you have a very clear understanding and aptitude to help trouble shoot this one particular issue to it's conclusion. Ok Here are the details. iPhone 4, GSM, 32 GB, 6.13, on Rogers Network. Older, No more warranty. There is no outgoing sound Cellular, regular and on speakerphone. (they can't hear me). Connects fine and I hear them perfectly. Mute is not on, overtly at least. This started 2 months ago. Mics work fine with all other software, including Skype voip calls without any issue. Have tried a different Rogers sim to test, same issue. Have done full restore a few times. Even did a tethered jailbreak to see if Jailbreaking could resolve it and No. So back to a full Apple itunes restore and same issue. I am down to software more so than hardware being that sound inputs works everywhere else except with cell calls, but ...being cellular related would the sound chip fix (pressure by plastic card on chip)shown on the internet work? is the hardware different for input cell sound than with input voip sound for example?? I know I may not get an answer to this but if someone really has some intelligent thoughts on this then you are probably helping thousands of iPhone users not only me. From reading around, this is common yet not solved. If you have a similar issue or took it into Apple for a replacement, Watch this post only Do not post "Me" stories and clutter with irrelevant text.