I accessed Samsung Kies and a screen message said that there was a firmware upgrade needed. I followed the screen prompt exactly and during the update a drop down message came up saying that there was a problem and to disconnect the phone from the pc,remove battery and switch on again. The phone screen had a large triangle saying "Do not disconnect the phone during upgrade" I left the phone connected but still the notice showed to disconnect the phone.I disconnected the phone as stated and removed the battery,then reinserted the battery and switched on the phone.All I got was a black screen with a phone icon - a yellow triangle with an exclamation mark init and an icon of a computer screen. Now all I get on the phone are the icons as just stated. Removing the battery and leaving it disconnected for 10 minutes before switching on only get those icons again. In Kies,it still shows "Connect a device" Any idea how I can sort this problem out ?
This question has been repeated many times.
Thankfully there is a way to fix it yourself but you kind of void your warranty, but nobody will know except you. Also depends which device you have.
What you need to do to fix it is go into Download Mode and use Odin or Heimdall to flash a Stock or if your daring custom ROM.
If you don't want to void your warranty take it to your SGS center and get it fixed by them.
It's a soft brick not a big issue.
If you want more detailed instructions please tell me the model number.