Guide for the HTC One (M8) - Troubleshooting - I can't make voice calls (Cause 4 of 9)

Step 1 of 5

Find "Network mode"

Slide two fingers down the display starting from the top edge of your phone.
Press SETTINGS.

Step 2 of 5

Find "Network mode"

Press Mobile data.

Step 3 of 5

Find "Network mode"

Press Network mode.

Step 4 of 5

Select network mode

Press 3G only, 2G only, 2G/3G auto or 2G/3G/4G auto.

Step 5 of 5

Return to the home screen

Press the home icon to return to the home screen.

1 Find "Network mode"

Slide two fingers down the display starting from the top edge of your phone.
Press SETTINGS.

Press Mobile data.

Press Network mode.

Press 3G only, 2G only, 2G/3G auto or 2G/3G/4G auto.

Press the home icon to return to the home screen.