iPhone 4 near to death!

[Authentic90]

I got this iPhone 4 from a friend and since I am an Apple lover, I accepted it although it was dead. Now, here's scenario. I have no idea what this phone has been through, upgraded or not upgraded and stuff like that and neither I have the SHSH blobs of this phone. All I know that this is an iphone which does not turns on itself but I have to connect it to my computer for it to boot.

Now, the phone is stuck in boot loop and doesnt seem to get out of it for like ever. I can get into the DFU mode but all in vain. When I try to Recovery Fix it with redsn0w, all the process happens but in the end, 'WAITING FOR REBOOT' comes on redsn0w and the phone is back in the boot loop.

I have tried everything like TinyUmbrella, Recboot, iFun and other softwares but it remains in the boot loop.

I have no idea what ios it has or to what it was upgraded. Redsn0w gives the following:-

Based on the last time this iPhone 4 connected in DFU mode:

CPID: 8930
CPRV: 20
CPFM: 03
SCEP: 01
BDID: 00
ECID: 0000029880044D4C
IBFL: 00
SRTG: [iBoot-574.4]

Rest, I'll let the experts give their opinion on this.

Thanks

 

[blueroom]

Apple's not signing 6.x anymore.

 

[Authentic90]

So, what does that mean?

 

[dictoresno]

So, what does that mean?

it means you cant reload or restore to it. you MUST upgrade to ios 7.

 

[nancyfromafrica]

take it to apple care and they will be able to help you may be it needs some email id or some apple id for you to login but with new OS installed you will be able to use the phone.

 

[blueroom]

Just do a DFU restore to iOS 7.x, don't bother with trying to jailbreak it.

 

[Authentic90]

So, here's the problem.

While I'm trying to restore iOS 7 via latest iTunes, either the phone goes into recovery mode from DFU mode and iTunes gives error code 21 and it stops.