1. Check power on switch first, replace button if needed.
2. If power on button is ok please check batteray connector, replace batteray connector if needed.
3. Try upgrade software then (reflash firmware).
4. If batteray connector is Ok measure resistance at batteray connector, if too low (short).
5. Check Voltage at C2203 & C2204 (about 3,7-4 Volt)
6. If needed replace C2203 & C 2204 (Capasitor)
