Thread: Urgently Need A Help For Error (21)

I got iPhone 3GS that came to me with this condition :
1-iPhone Keep Stay in turn off ( No Backlight )
2-I can not turn on it
3-I can not let it go into "Recovery" Mode
4-I can nonly put into "DFU"Mode.
5-I don't have SHSH 3.x blob save

When I try to restore it with iOS 4.x, iTune start to repare it for restore and it make iPhone turn on with in backlight on, then it come to white screen, and then PC or Mac detected error on usb port, then iTunes just show me an error code (21).

I have tried with many PC ( including change usb port, windows XP, Vista, Seven ) and Mac also... but still keep this error.

And I have tried with method to creat new user on PC and Mac, but still get error with code (13).

So please help me how to fix this?

Please Help!!! I really Need...

some time error 21 its hardware problem but try to take batt off for a min. good luck

I have before same problem on Iphone 3GS 16gb . symptoms :1-iPhone Keep Stay in turn off ( No Backlight )
2-I can not turn on it
3-I can not let it go into "Recovery" Mode
4-I can nonly put into "DFU"Mode.
5-I don't have SHSH 3.x blob save

When I try to restore to v4.0.1 phone go to recovery mode (withe screen) and get error 21 .But now you can save SHSH !!! with AutoSHSH-3.1.3_3.2--RC2.exe .
Error 21 is hardware problem in my case . I repair my iphone with rehot some ICs BUT this is very dangerous
B.R. ribaria

can you show me the procedure of reheet please?