8 Replies Latest reply: Jan 5, 2015 12:28 PM by MobileHero
jorisvdbe Level 1 Level 1 (0 points)



A few months ago, my iPhone 3GS started rebooting every 5-10 minutes, only when the mobile network was activated.

I did a hard reset, and everything was fine again.


But now, there're problems again... Now, the iPhone resets 3-5 times a day, but also when airplane mode is activated.

When you look at the crashlogs, it's always because a "WDT timeout". There's one other topic about this subject (https://discussions.apple.com/thread/3500622?start=0&tstart=0), I tried every possible solution, but it didn't help.

I didn't try a hard reset (yet), because I don't think it's convenient to do this every few months or so.


My questions are:

1- What's the WDT-process?

2- Anybody has a solution for

(the Apple helpdesk didn't seem keen to help me) 


Thanks in advance!


Kind regards,


iPhone 3GS, iOS 5.0.1
  • franknoort Level 1 Level 1 (0 points)

    Hi Joris


    Got an update already. I've got the same problem here on iOS 5.0  and would like to know the final solution.






  • thelookingglass Level 1 Level 1 (0 points)

    I too would like to know what the WDT timeout is in panic.plist as I've all of a sudden been experiencing kernel panics on my iPad 2.

  • Lawrence Finch Level 7 Level 7 (28,880 points)

    Is it jailboken? The only times I've read about WDT (Watchdog timer) errors is on jailbroken devices.

  • thelookingglass Level 1 Level 1 (0 points)

    Nope, that's the odd thing. Never jail broken and never will. Doesn't appeal to me at all.

  • Lawrence Finch Level 7 Level 7 (28,880 points)

    The WDT monitors apps, and kills them if they don't respond within a preset timeout (all apps are supposed to "check in" with iOS frequently*). If it's a built in app that doesn't respond you will get a kernel panic (sort of like a Windows Blue Screen of Death). As to WHY a built in app isn't responding, it's as much a mystery to me as it is to you. As a start restore the device with iTunes and set up as New. Add only email accounts and test. If it doesn't crash after a while add back other apps. If it crashes as New you've got a hardware problem.




    *For all you developers who just cringed, please forgive my gross oversimplification

  • thelookingglass Level 1 Level 1 (0 points)

    Thanks, very helpful explanation. I will try restoring from new and see what happens. Odd, though, that this would only happen in the last month after having used the device for nearly a year. Could it really be a hardware issue if the problem only started recently?

  • franknoort Level 1 Level 1 (0 points)

    Very helpful indeed. I was at the Apple Store yesterday and they stated it was a hardware problem. Want to makse sure with this methors to see if they are right.


    Made a fresh start today, installed the basis iOS 5.0.1 with a very few applications. Lets see how long this will last.

  • MobileHero Level 1 Level 1 (0 points)

    Was the restore as new device helpful?


    Same on iPhone 5. Since iOS 8.1. "panic.ips" in diagnostics, "WDT timeout". Seems to be a software bug. It seems I meanwhile detected a pattern: From time to time when doing app store updates it happens. A few minutes ago again with the facebook app. Could it be a storage issue (iPhone is pretty full!)?