mine started to do the same,i downgraded,upgraded, tried tbh unlock,custom roms,but nothing works. funny is that i have silence on outgoing call on 2g network,incoming calls are fine.on 3g network works ok,but signal is awfull(t-mobile,CRO).
This and wifi on/off problem turned my d2g into piece of cr*p,wondering if any new OTA update comes ,it will bring function that phone cannot power from power button or such.
OK, so i was trying many things and then suddenly found a solution for DTMF dialing. If you are using the GMS of D2G, just set your phone to GSM only and also use 2G. Some how on 3G it can't dial the dtmf. Try it and let me know. I am able to call the ATT conference number in 2G.
Maybe someone should look at how the calls are being made on both frequency and have a fix.
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