HTC Touch Diamond, one of the major competitor to iPhone 3G, is a Windows Mobile 6.1 powered Pocket PC Phone. It comes with a 3-axis accelerometer that senses the orientation of the phone, and able to mute the incoming call ringing tone audio alert if the user flip the phone face down.
Mute phone on face flips or turns down is a convenient feature, especially when one is in the meeting or private business discussion. But probably not everybody wants the flip phone to mute ringing tone feature,, as one may accidentally flip over the HTC Touch Diamond, and on hearing the ringtone sound off, falsely believe that the caller has hanged up the call, when actually it’s not the case.
To switch off the mute call on phone flipped face down option in HTC Touch Diamond, use a registry editor such as PHM Registry Editor, which although has not been updated, but still can be installed on WM6 by installing the .CAB file on mobile device directly.
Navigate to the following registry key:
Locate a registry entry named FaceDownMuteRing. FaceDownMuteRing has the value of 1 by default (enabled). To turn off and disable the mute call on phone face flips down feature, set the value for FaceDownMuteRing to 0 (disabled). Once set, the phone will keep ringing no matter how you turn, twist, shake or flip the Touch Diamond.