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any idea what error 3503 is?

I was updating my iPad to the latest iOS version and the install crashed. whenever I'm trying to reset the iPad I get a message from after it extracted the firmware that the iPad couldn't be restored and that an unknown error occurred (3503). Any clue ?

Posted on Nov 30, 2016 5:12 AM

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Posted on Sep 24, 2017 3:56 PM

You have to turn off "Find My iPad/iPhone" first, then go through the steps of connecting to iTunes and update/restore. You can turn off "find my [device]" by logging in to the apple website from your computer.

187 replies

Sep 24, 2017 4:15 PM in response to Ble75

It's an issue with the TSS server. It gives the following output:

Sending TSS request attempt 1... TSS server returned: <html>

<head><title>403 Forbidden</title></head>

<body bgcolor="white">

<center><h1>403 Forbidden</h1></center>

<hr><center>Shield</center>

</body>

</html>

Basically, it's on Apple's side. It's NOT an issue with your devices. Just wait a little while for them to fix it.

Sep 24, 2017 4:16 PM in response to Ble75

Don't smash your brains out thinking. I just re-install my old Vaio with win 11. Install itunes 12.7 and tried again to update my iphone 7. Guess what!! Got the same error (3503) Also tried to install iOS 10.3.3 same thing. So this for sure apple's problem. I got my own cellphone workshop and do this all the time never saw this error before. Got to wait until tomorrow see what happends.

Sep 24, 2017 8:03 PM in response to Ble75

I was dealing with the same issue and since I am in urgent need of my ipad I was able to download this software (http://www.iphone-ipad-recovery.com/recover-ipad-data-and-get-out-of-recovery-mo de.html). Once downloaded on my PC, I chose the option to restore from recovery mode/black screen and my ipad wasnt recognized immediately, but upon a second try my ipad came out of recovery mode and I was happy to see my lock screen and no deleted apps! I hope I was able to help someone 🙂

Sep 24, 2017 2:57 PM in response to Ble75

I have similar problem with my iPhone 7, iPad mini 4 and iPhone 6S. I think it's problem of iTunes not been able to connect to update/restore server. Best to try on another computer just in case any program installed or virus is working in the background. Try your own solutions 'cause this guys don't know ****...

Sep 24, 2017 3:12 PM in response to Ble75

I'm having this problem too, which is weird because I was able to restore it just yesterday. Did you do an icloud backup right before trying to restore? Because that's the only thing I did differently today and am now getting the 3503 error. I've reinstalled itunes, tried different usb ports, and put my iphone in recovery mode but I still can't restore it.

Sep 24, 2017 3:23 PM in response to Ble75

I have the same problem today on September 24th. After I wanted to restore my ipad air 2, I am stuck with the Itune screen and the white cable and the arrow and an error 3503 not listed .... Not the only one to have this problem. Hard reset (Home button + power) does not work.

J'ai le meme probleme aujourd'hui le 24 Septembre. Après avoir voulu restaurer mon ipad air 2, je suis bloqué avec l ecran Itune et le cable blanc et la fleche et une erreur 3503 non listé.... Pas le seul a avoir ce probleme. Le Hard reset (Home button + power) ne fonctionne pas.

Sep 24, 2017 3:50 PM in response to Ble75

It is obviously an issue today


i am just trying to do a force update , I already have iOS 11 on both IPhone 6s Plus and IPad Pro 10.5


but I am thinking I may have some bugs so instead of going straight to factory restore I am doing a update of iOS 11 but I keep getting ERROR 3503


so I think there is an Apple update server issue


let me know what you guys think

Sep 24, 2017 4:53 PM in response to golephish

I've chatted with them twice. Advised me that they had never seen this error code before, and I had tried everything prior to try and restore. I'm sure they've logged it so hopefully due to many people getting it can be resolved.

They tried to set up repair for me but I was going to take it to my repair center tomorrow. Might hang on to see if anyone has an answer.

any idea what error 3503 is?

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