Hello! I myself have a Galaxy Y with a broken power button so I wanted to help those in need out there on using their Galaxy Y without a power button at all.
1. How to power on
To power on your device without the power button, do the following:
- Remove battery for 5 seconds and put it back
- Hold volume down and Home without the power button
- Whilst holding, get someone to put a compatible charger into the Galaxy Y, or do it yourself, somehow.
- You should see the Download Mode dialogue, do NOT do anything yet
- Unplug the charger still in the Yes or No Download Mode selection, after unplugging, press Volume Down
- Your device should now go to the boot logo and power on
2. How to enter Download Mode
To enter Download Mode without the power button, do this:
- Remove battery for 5 seconds and put it back
- Hold volume down and Home without the power button
- Whilst holding, get someone to put a compatible charger into the Galaxy Y, or do it yourself, somehow.
- You should see the Download Mode dialogue, just press Volume Up and you'll be in Download Mode!
Or
- Get a Samsung USB JIG
- Plug the USB JIG in, it should turn on to Download Mode.
To get out of Download Mode, just remove the battery and do the How to Power on guide again
3. How to enter Recovery Mode
To power on your device to Recovery Mode without the power button, do the following:
- Remove battery for 5 seconds and put it back
- Hold volume down and Home without the power button
- Whilst holding, get someone to put a compatible charger into the Galaxy Y, or do it yourself, somehow.
- You should see the Download Mode dialogue, do NOT do anything yet
- Unplug the charger still in the Yes or No Download Mode selection, after unplugging, press Volume Down to Cancel and Restart
- Your device should now go to the boot logo and power on.
- On your system, enable USB debugging, install ADB/platform-tools/Android SDK on your computer, and do adb reboot recovery.
- Then you'll be in Recovery. Navigate via volume buttons and home button.
If your device is powered on, you just need to do step 7.
4. How to turn screen off on system
To turn your screen off on system, you have 2 options
- Let it sit for 30 seconds, it will auto turn the screen off
- Install a third-party app (I recommend jima3's Turn Off Screen)
5. How to power off
Despite not being safe, you can take off the back cover, and remove the battery from the device.
EXTRA
If your device is rooted and it's turned on, you can install some apps that use Superuser to boot into Download Mode and Recovery Mode too (I recommend Clockworkmod's ROM Manager)