Chosen Solution
To my dismay I bought a second hand iPad Pro 10.5 from a dishonest seller who promptly blocked me after the sale, having concealed the device’s bootloop problem which renders it a brick. Seems like this is a known issue that turns up in Google search that upgrading to iPadOS 13.4.1 (iPadOS 13.4?) may brick the some iPads into bootlooping, with iPad Pro 10.5"s being particularly vulnerable. The most detailed thread on this issue is found on the Apple discussions forum, but a solution has yet to be found: https://discussions.apple.com/thread/251… None of the typical solutions to bootlooping such as force restarting, restoring in recovery/ DUF mode, nor updating to the latest firmware fixes the issue. Several users have posted their crash analytics and one of the culprit issues seems to be related to the iPad’s ’thermomonitor’ check. With this lead I was able to find a temporary solution in putting the iPad into the freezer. This seems to bypass the thermomonitor check and allows the iPad to function past the boot screen, though only for about 10-20 minutes before the device returns to room temperature and goes back to bootlooping. Some others have had success with squeezing the iPad or dropping it to alleviate the issue. The first snippet of my panic-full text shows: “{“bug_type”:“210”,“timestamp”:“2020-07-20 23:18:10.00 +1000”,“os_version”:“iPhone OS 13.6 (17G68)”,“incident_id”:“052139FC-0CBC-435B-B14E-86F0B115C5FF”} { “build” : “iPhone OS 13.6 (17G68)”, “product” : “iPad7,4”, “kernel” : “Darwin Kernel Version 19.6.0: Sat Jun 27 04:36:05 PDT 2020; root:xnu-6153.142.1~4/RELEASE_ARM64_T8011”, “incident” : “052139FC-0CBC-435B-B14E-86F0B115C5FF”, “crashReporterKey” : “5f9fffa2032645ae219b1d236756e0b28989c1e6”, “date” : “2020-07-20 23:18:04.96 +1000”, “panicString” : “panic(cpu 1 caller 0xfffffff015da6540): "AMCC Error! AMCC_IRERRDBG_INTSTS=0x1000000, MCCTAGPARLOG1/2=0/0, MCCDATERRLOG=0, MCCAFERRLOG[0..2]=0xfffff080/0x1f140f/0xa044, RNKCFG[0..3]=0x6011/0x6011/0x6011/0x6011"@/Library/Caches/com.apple.xbs/Sources/AppleT8010/AppleT8010-63.0.1/AppleT8010PlatformErrorHandler.cpp:269\nDebugger message: panic\nMemory ID: 0x6\nOS version: Not set yet\nKernel version: Darwin Kernel Version 19.6.0: Sat Jun 27 04:36:05 PDT 2020; root:xnu-6153.142.1~4/RELEASE_ARM64_T8011\nKernelCache UUID: C5AF7A5E78CF1631FEB7A5BEB39C5FC3\nKernel UUID: 8112CE26-A0EC-39C5-8E50-B83C0E62CEBE\niBoot version: iBoot-5540.140.12\nsecure boot?: YES\nPaniclog version: 13\nKernel slide: 0x000000000f054000\nKernel text base: 0xfffffff016058000\nmach_absolute_time: 0xba44c5c\nEpoch Time: sec usec\n Boot : 0x5f15997c 0x00099a36\n Sleep : 0x00000000 0x00000000\n Wake : 0x00000000 0x00000000\n Calendar: 0x5f15997c 0x000a4561\n\nPanicked task 0xffffffe0004a0800: 2765 pages, 178 threads: pid 0: kernel_task\nPanicked thread: 0xffffffe00086cfd8, backtrace: 0xffffffe0712378a0, tid: 489\n\t\t lr: 0xfffffff01618a258 fp: 0xffffffe0712378e0\n\t\t lr: 0xfffffff01618a0b4 fp: 0xffffffe071237950\n\t\t lr: 0xfffffff01628925c fp: 0xffffffe071237a00\n\t\t lr: 0xfffffff01614d5d8 fp: 0xffffffe071237a10\n\t\t lr: 0xfffffff016189a1c fp: 0xffffffe071237d80\n\t\t lr: 0xfffffff016189d74 fp: 0xffffffe071237dd0\n\t\t lr: 0xfffffff01673bcc8 fp: 0xffffffe071237df0\n\t\t lr: 0xfffffff015da6540 fp: 0xffffffe071237e60\n\t\t lr: 0xfffffff015da27a8 fp: 0xffffffe071237f20\n\t\t lr: 0xfffffff015a656c8 fp: 0xffffffe071237fb0\n\t\t lr: 0xfffffff0166da854 fp: 0xffffffe071237fc0\n\t\t lr: 0xfffffff016289e34 fp: 0xffffffe071237fe0\n\t\t lr: 0xfffffff01614d628 fp: 0xffffffe071237ff0\n\t\t lr: 0xfffffff016690b2c fp: 0xffffffe07014b5e0\n\t\t lr: 0xfffffff016690b2c fp: 0xffffffe07014b600\n\t\t lr: 0xfffffff01668e4b8 fp: 0xffffffe07014b660\n\t\t lr: 0xfffffff01668e428 fp: 0xffffffe07014b690\n\t\t lr: 0xfffffff014ec9ffc fp: 0xffffffe07014b6c0\n\t\t lr: 0xfffffff0166920c0 fp: 0xffffffe07014b700\n\t\t lr: 0xfffffff01669b550 fp: 0xffffffe07014b770\n\t\t lr: 0xfffffff01669f7e4 fp: 0xffffffe07014b7b0\n\t\t lr: 0xfffffff01664c36c fp: 0xffffffe07014b960\n\t\t lr: 0xfffffff01664c4b8 fp: 0xffffffe07014b9a0\n\t\t lr: 0xfffffff01669f068 fp: 0xffffffe07014ba10\n\t\t lr: 0xfffffff0166a5a98 fp: 0xffffffe07014ba30\n\t\t lr: 0xfffffff0150a18e8 fp: 0xffffffe07014ba80\n\t\t lr: 0xfffffff01669e1d4 fp: 0xffffffe07014baf0\n\t\t lr: 0xfffffff01669decc fp: 0xffffffe07014bbb0\n\t\t lr: 0xfffffff01669d238 fp: 0xffffffe07014bc20\n\t\t lr: 0xfffffff01669fd2c fp: 0xffffffe07014bc90\n\t\t lr: 0xfffffff016158654 fp: 0x0000000000000000\n\n”, “panicFlags” : “0x2”, “otherString” : “\n** Stackshot Succeeded ** Bytes Traced 59856 **\n”,…” What would be a potential cause of this malfunctioning that freezing the iPad after a firmware update would allow it to work temporarily? Is this something that may be reversible with a future update, or is the device permanently bricked? This issue appears to be similar to the recent Google Nexus 6P’s Bootloop of Death where likewise a workaround with temperature tripping with heat/ cold prevents the reboots and allowing it to work temporarily. Does anyone more tech-savy here have the same issue? Is there absolutely no way to downgrade to an unsigned firmware without existing blobs?
Seems like concerns may have been heard and a solution implemented, though in Beta software. iPadOs 14 Public Beta 2 now (works for me) or Beta 3 has been successful for others.
It is unclear if Apple is officially working on a fix for the issue, though it is also unknown what actually causes it to manifest for a relatively small number of users and not the iPad Pro population at large. So far, interim advice ahead of a patch seems to revolve around putting the iPad Pro through a hard reset procedure before it reboots, to try and escape the reboot loop. https://appleinsider.com/articles/20/05/…
My partner’s iPad has been essentially bricked because of this and has been for a long time now. 13.5 was when we noticed the issue but we’ve been able to update to (at 14.4 now) when we manage to get the device booted re: the hard reset interrupt method (crashes back to bootloop after 30 minutes tops). Unable to restore from IPSW via iTunes on a Mac or Windows machine (iTunes sees the iPad in recovery/DFU, but just doesn’t… do anything or give any feedback after I feed it the IPSW). Tearing our hair out over this! Their device was bought refurbished, and seemed to be giving a little fuss in logs (viewed in XCode) about the digitizer — not sure if this is a false positive but thinking it could be related. Sorry I can’t be any more help, just want to help document this issue since Apple’s done nothing!