iPhone 4

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.

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iPhone 4 error 21 and will not start

Hello, i have a big head cracker, LOL

So I buy this iphone 4 as faulty, cheap... I knew the phone was stuck in in restore mode and I was thinking that all it needed was to plug and restore, nothing is easy in live, and this is no different.

So if I plug the phone to the wall or PC I get the apple logo on the screen, if the phone is not connected to wall or PC, the phone will not turn on nothing happens not even if I press the power and home button.

I now the battery is fully charged so it should power on, but it does not, only if connected to wall or PC. Is this normal? the phone doing this with error 21 the battery connector looks in good shape, and i tried the battery on other iphone and it works.

So when I connect to PC and try to restore I will get the error 21, so I Google a fix and do as instructed. I deleted a ETC file and a different error appear, all I needed to do was update itunes, so I try again to restore but error 21 comes up again With or without ETC file (file is in recycle bin).

I think the phone must have been jailbreak... But if anyone have any ideas please help... I afraid the logicboard might be busted, but the PC recognizes the phone and installs the divers needed... I just to novice at iphones :) i gess...

Thanks guys and sorry for the big love letter, LOL

I read in some forum about custom ipsw and TinyUmbrella but i have no idea how this will help, i tried redsn0w but it did not work i just tried the jailbreak option.

Thanks

Answered! View the answer I have this problem too

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hi cesar how is your phone is fix?? let me know bcuz i have the same problem and i do not know what to do, thank you

by alarcon684

this link is for what happend to me after trying everything a could http://www.ifixit.com/Answers/View/10478...

by cesar

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Chosen Solution

I had a similar poblem with my iPhone 4.

what made is:

- unpluged my touch panel connector from the motherboard

- cleaned it up (no liquid)

- I pluged it back correctly

- than I restarted my iPhone

It fonctions.

try it, you have nothing to lose.

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Hi, im on the same problem... Finster, could you explain what the touch panel connector is?

by Patrick

Sorry for english, i'm french. It's the digitizer cable that can see in yellow at step 18 in this page http://www.ifixit.com/Guide/Installing-i...

by finster

ok, lets look at the connectors first. sorry i have been very busy with work but ill turn to the phone now :) Patrick the problem you had, was it becauso your phone was in recovery mode or would no start up?

by cesar

Is it just the cable or the whole module?

by Patrick

You can't separate the cable from the module, so I think that it's a fitting problem.

by finster

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Most Helpful Answer

if you already ruled out the battery for being defective, then proceed to the next suspect, which is the battery connector located on the logic board or mother board, try to check if its mounted properly, all the legs must be soldered properly and intact and clean. then if you ruled out the battery port or connector on your logic board and still having the same problem then proceed to the dock port or charging port (where you connect your sync cable or charger cable), try to clean it or better replace it. you can check in youtube the step by step procedure, if you already performed all these 3 things, and still having the same problem, try replacing the voltage regulator also located at the logic board, it looks like a tiny black color square shape thing, youtube can help you locate it. you need a very good skills of replacing this part, all of these steps are inexpensive repair, but like i said, you need a good troubleshooting and soldering skills to be able to perform those repairs, if you did all those and the problem still persist, it must have a serious mother board problem, the phone maybe water damaged before, you cant assure anything if the phone dives in the water, just tryin to help.

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I know this is a long time later, but people still read these things.

I fixed a phone with an error 21 behaving the same as the original post. Upon closer inspection I found one of the tiny wires/pins on the battery connector was bent. A gentle tap and it was all lined up for the battery to plug into.

Problem solved.

Worth a try for a cheap fix.

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Hello Cesar,

I think your iphones battery connector is broken, open the back cover and remove the battery and check the battery connector .

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I have tried 3 different battery's, they work fine on my other iphone.

by cesar

I mean the battery connector on the logic board, that causes this problem.

by Denis

this link is for waht happend to me after trying everything a could. http://www.ifixit.com/Answers/View/10478...

by cesar

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any luck ?

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press home and power button at same time wait for apple logo release , if still dosnt work change battery and usb port

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cesar will be eternally grateful.

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