stuck in Apple logo boot loop

Hello everyone

my iphone 4s keeps rebooting whether its on charge or not.

what i have tried so far..

1. tried a different battery - no change

2. tried the 4s battery into another iphone 4s works fine. so its not the battery issue.

3. tried hard reboot - failed

4. tried restoring in recovery/ DFU mode itunes spits out error 9

5. also toredown the phone cleaned it still the same error.

6. also removed the lcd flex cable shield and tried to restore - failed (one of the answers here was error 9 occurs due to screwing the shield tight)

itunes and macbook updated and no security software enabling me to restore.

can anyone come up with something different? thanks