Originally Posted by vprabs
I tried to put the phone in download mode when battery is removed, however there was no message/flicker either on the screen and the computer did not recognise any device. I held the vol+ and vol- buttons together for about 15 seconds.
Sounds like a true brick. The phone is getting old enough that it may not be cost effective to send it out for repair. But if you do choose to go for a repair, Mobile Tech Videos in LA has a very highly respected reputation here.
There are several ways to put the phone into download mode. You should try all of them that you can before you give up.
With the phone off (and not connected to the computer), and battery installed, hold all three buttons, vol- vol+ pwr continuously until the initial boot screen appears the second time.
1. With the phone off and connected to the computer via USB cable, and battery installed, hold all three buttons, vol- vol+ pwr.
2. With the phone off and battery installed, hold vol- and vol+ (but not pwr) while plugging in the USB cable.
3. With the phone off and battery installed, hold vol- (but not vol+ or pwr) while plugging in the USB cable.
4. Attempt each of the above three options with the battery removed from the phone. The computer will supply the power to the phone.
5. Use Android Debug Bridge (adb) which will only work if USB debugging has been already turned on in Developer Options, since you can't boot into the system to turn it on. With the battery installed and the phone connected to the pc via USB cable, use the command "adb reboot download".
6. Use a USB jig. With the battery installed insert the USB jig into the USB connector of the phone. Some have reported that this method works when no other method would work.