I don't have any background information, but my coworker showed up today with a nonresponsive Samsung Galaxy Gio. It will not boot. When plugged into the power charger, a half-full battery displays and just stays there.
Attempting to turn it on while holding the home button has no effect.
I swapped batteries with her (this is a company phone; we all have the same model). My phone works fine with her battery, hers does not work with my battery. Tried gently brushing off the battery contacts in her phone, no go.
Anything else to try before sending to the manufacturer?