I've found a much better way to identify the signal drop issue and I've also found an app that will run a script at boot to disable the auto voltage setting. My phone has been rock solid in testing all day. The fix requires root access (just like the command line method) so it may not be for everyone - but if you've got an unlocked bootloader you might as well give this a try.
Easy Test For Issue
The quickest way to see if you have the issue is to do the following with the phone unplugged from charger or computer:
1. (Optional, but recommended) Install "No Signal Alert" from the Market.
2. Disable wifi.
3. Disable mobile data (Settings->Data Usage->Mobile Data OFF).
4. Set your display timeout to 30 seconds.
5. Reboot your phone.
7. Wait for you display to go to sleep (30 seconds after boot).
8. If you installed No Signal Alert you should hear a beep within the next 30 seconds, otherwise wait 30 seconds, power on your screen to check your signal. If you have the issue you will see your signal has dropped. With No Signal Alert installed, if I manually turn off the display my phone will beep within 5 seconds because I've lost signal.
It would be interesting to get feedback from people on 4.0.4 who aren't seeing the issue. Wonder if a few begin to see it by following the above steps.
Disabling data seems to accelerate the issue - presumably because the radio is not being used to send data so it goes to sleep much quicker...
Easy Fix For Issue
This will require you have
superuser.apk installed.
1. Unzip the attached script (radiosaver.sh) to /sdcard on your phone.
2. Download and run "Script Manager" from the Market.
3. From within Script Manager, click on radiosaver.sh file in /sdcard.
4. Click the Su and Boot icons to grant superuser and run at boot (see attached).
5. Click Save, exit the app and reboot your phone.
6. Upon reboot the app will request superuser permissions, click yes.
If everything was done properly then run through the test above and you should still have signal. Don't forget to re-enable data & wife when you're done
The attached script just contains the following command to disable auto voltage as suggested earlier in this thread:
echo 0 > /sys/kernel/debug/smartreflex/sr_core/autocomp
Like I said, for me it didn't matter what radio I was on or what ROM, if I'm running 4.0.4 it would just fail. Also, I also tried a SIM from Wind (different provider) and it also failed.
Hope this helps at least preserve battery life for those who were using the SetCPU fix. Good luck!
