help me please

i have iphone 3gs , after trying upgrade ipad baseband got error itunes saying : " itunes not restore iphone unknown error (-1)"
have been searching 6 hours , have not seen error. phone stuck in restore mode have tried dfu , clean restore , nothing works.

 

Forums iPhone, iPad, and iPod Touch Jailbreaks and iOS Hacks

• iPhone
• Mac OS & System Software
• iPad
• Apple Watch
• Notebooks
• iTunes
• Apple ID
• iCloud
• Desktop Computers
• Apple Music
• Professional Applications
• iPod
• iWork
• Apple TV
• iLife
• Wireless