iPhone Restore/Flash Error Code Lookup

Full error-code table

Code	Cause	Fix
9	Disk not read/power	Change PC, check disk power, retry
11	C: drive full	Free system disk space
14	Insufficient power/USB	Genuine cable + rear USB2.0
40 / 4013 / 4014	Hardware comms (disk/CPU/I2C)	Genuine cable + rear port, disable AV, change PC
53	Touch/Face ID auth	Re-restore via hotspot; module repair if dead
3194	Target firmware unsigned	Only flash a signed version / edit hosts
3004	Server refused/signing closed	Update client/use proxy
-1	Baseband comms failure	Mostly hardware, change cable/port
-50	Server timeout	Check proxy/network, update client
35/37/38/41/47/48	Disk failure	Test/replace disk

General troubleshooting order

Genuine MFi cable + rear USB2.0 (no hub)
Update OS/i4/iTunes
Disable firewall/AV, run as admin
Toolbox 'iTunes & driver repair'
Force restart into recovery/DFU
Change PC -> repair shop

Force restart / enter DFU (by model)

Model	Action
iPhone 8 and later	Quick Vol+ -> quick Vol- -> hold Power to recovery
iPhone 7/7P	Hold Vol- + Power together
iPhone 6s and earlier	Hold Home + Power together

About downgrading (SHSH)

Whether you can downgrade depends on Apple still signing that version + whether you saved SHSH. 'Can flash' in i4 doesn't mean it'll succeed; after signing closes it fails mid-way or sticks at activation. Check 'Query SHSH' first.

FAQ

Fails at 80%?

Past 80% it's usually baseband/power, near 60% the disk. Try genuine cable + rear port first.

Is 3194/3004 a signing block?

3194 = target firmware unsigned (only flash a signed version); 3004 is usually a server/verification issue.

Can error 53 be fixed?

In 2026 it's mostly a fingerprint/Face ID module fault needing repair; first re-restore over a hotspot to rule out software.

Repeated errors?

Don't keep retrying or yank the cable (it enters DFU); 'Exit recovery mode' first, then change PC/cable.