Fourth generation iPhone. Repair is straightforward, but the front glass and LCD must be replaced as a unit. GSM / 8, 16, or 32 GB capacity / Model A1332 / Black and White.

3256 Questions View all

Is it possible to reset phone motherboard?

Hi, I bought an iPhone 4 (gsm) believing that it had a battery issue. Turns out it had been jb using greenpoison, I just want the original iOS back. If I put it into recovery mode or dfu mode iTunes detects it, but won't restore it. I have tried other cables, other computers but still get error 21, 1601, 1602 or 3194. Even after editing host file & turning off firewall and anti virus software.

My question is this: Is there a reset button/switch on the motherboard itself? If so, where is it & what is the best way to use it? Thanks to anyone who can help


Answered! View the answer I have this problem too

Is this a good question?

Score 1



iphone 4 se quedo con el simbolo de itunes y no lo puedo sacar /error 21 use varios programas sin resultados

????? hay solucion ?



Add a comment

1 Answer

Chosen Solution

Hi Pixxi

There is no reset button on the Logic Board of iPhone 4.

And if you are trying to restore it on the latest iOS then you don't need to edit the host file.

If you have a unlocked iPhone and no issues in going to latest iOS then i would recommend to uninstall iTunes and install it back so that you get the original host file and try restoring it back.

Still the iTunes is not able to restore it then it seems to be an hardware issue.

Keep us posted so that we can help you further

If you think i answered your question please rate (score) and mark it accepted. :)


Was this answer helpful?

Score 0


Thank you for the quick response. I was so hoping that there was a "magic" button on the motherboard. Do u think it might have something to do with it being jb with greenpois0n before I bought it? If I uninstall/reinstall iTunes how likely is it that I will lose all my apple device back ups? I have two iPads & an iPod backed up at the moment. I have even tried downloading that latest .ipsw file and doing shift+restore in iTunes and manually selecting it and still nothing??


I am not sure about loosing the backup after uninstall, to be on a safer side we will not do the uninstall.

My intention to uninstall iTunes was to get the latest host file as we get from fresh install of iTunes.

if you can edit the host file as it was originally that should do.

also you got the same errors this time too when you tried the restore ?


Unfortunately, yes I did get the same errors. I also got a fresh host file from apple and replaced the one that was there. I also tried logging into my iTunes account, connecting the phone and then doing the restore. Still get the error and the phone reverts to the recovery screen but isn't recognised any longer by iTunes. Although if if I restart iTunes it's recognised again???


:( okay

Can we try to put the phone in DFU Mode and try it once.

The procedure of putting a phone in DFU mode is

Then try to restore it once.


I put into DFU mode, opened iTunes as administrator, once recognised, I clicked restore, got the usual warning about device being wiped & updated clicked ok. Still getting error 21 :-(


Show 6 more comments

Add a comment

Add your answer

Pixxi will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 10

Past 30 Days: 32

All Time: 8,508