Try a reset...
1. Remove battery, and disconnect mains adapter.
2. Press and hold down power ON button for 30secs at least.
3. Put the battery back.
4. Plug in mains adapter then Power ON as normal.
If orange light still flashes the new battery you bought is probably not compatible.
Some of those cheap batteries not officially supplied by Toshiba are poor quality and it's false economy to buy them.