Samsung D880 Dual SIM tips

You can master reset your phone for default setting:
type *2767*3855# ( this is Hardware-Full Reset for advance user)

after this every setting back to default. so you can set voice again

Code *#4777*8665# for GPRS Tools Menu manual start for saving power .
* menu [2] GPRS detach
* menu [5] Attach Mode Setting
* select "Manual attach" press OK

solving Slave SIM increase voice:

* Test Mode Menu Code: *#0206*8378#
* Menu [2] H/W test
* Menu [2] Audio Settings
* Menu [15] Audio AMP
* Write [14] SLAVE_IOM2_NORMAL from 13 to 18
* Write [15] SLAVE_IOM2_HEAD from 19 to 26
* go out of menus

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