Galaxy S4 grey battery with known full battery.

[caseym54]

My wife and I have two identical Galaxy S4s. Suddenly, her S4 stopped charging, and displays the grey battery icon while the charger is connected.

• If you insist on booting the phone, it will boot to the normal screen, but show 0% battery and "charging". No amount of charging gets it out of this mode. It stays at 0%.
  
• If you attempt to turn the device on with the charger disconnected, it displays the GS4 logo for about 2 seconds, then goes dark and fails to boot.
  
• Removing a known full battery from the other, good, phone does not alter this behavior -- still get a grey battery, 0% and no joy. If you then swap the battery back into the good phone, it shows up at 100%.
  
• Tried 4 chargers with separate USB cables.
  
• Tried cleaning battery contacts with 91% isopropanol. Also eraser. And yes, the battery is in right way around.
  
• Tried air blasts into charging port. Examination of charging port shows no gunk, and the USB center conductor is clearly not touching the case ground.

Phone is still (barely) in warranty, but I'd prefer to fix it myself if there's a simple fix.

 

[caseym54]

Fixed with a trip to AT&T's repair shop.

 

[dplong76]

You said your phone was fixed with a trip to AT&T repair shop, but did they tell you what the diagnosis was, or tell you how they fixed it? I have the same problem, but I don't think T-mobile has a damn repair shop i can take it to.

 

[caseym54]

No. You might try Best Buy or some such.