iPhone XS turning itself off after using for a while

I decided to buy some phones for me to fix and sell, and the only one thats unlocked and somewhat working is just randomly shutting down and starting up again. Sometimes even when not in use. The battery is probably not the problem since i tried with 2 different batteries.

The only two things that come to my head is the iPhone X display i use for testing instead of iPhone XS display.

And I also see some signs of water entering inside the phone, and leaving residue.

I decided to hook it up to a pc and see the status in 3utools, and I got the crash analysis.

{"bug_type":"210","timestamp":"2025-02-23 22:56:28.00 +0100","os_version":"iPhone OS 18.3.1 (22D72)","roots_installed":0,"incident_id":"91E7B75A-E7F8-4C43-8A0C-A9B4F3457D5A"}

{

"build" : "iPhone OS 18.3.1 (22D72)",

"product" : "iPhone11,2",

"socId" : "8020",

"socRevision" : "11",

"incident" : "91E7B75A-E7F8-4C43-8A0C-A9B4F3457D5A",

"crashReporterKey" : "7cce604b5653db7edfdf808dbb852d4c8181f671",

"kernel" : "Darwin Kernel Version 24.3.0: Thu Jan 16 02:59:12 PST 2025; root:xnu-11215.82.4~20\/RELEASE_ARM64_T8020",

"date" : "2025-02-23 22:56:28.11 +0100",

"panicString" : "panic(cpu 1 caller 0xfffffff0254d6354): userspace watchdog timeout: no successful checkins from thermalmonitord (2 induced crashes) \nservice returned not alive with context : is_alive_func returned unhealthy : current 6ffffffffffff, mask 37ffffffffdff, expected 37ffffffffdff. SD: 0 BC: 0 RC: 0 BS: 1, Missing sensor(s): Prs0 \nservice: backboardd, total successful checkins in 198 seconds: 19, last successful checkin: 0 seconds ago\nservice: SpringBoard, total successful checkins in 170 seconds: 17, last successful checkin: 0 seconds ago\nservice: audiomxd, total successful checkins in 198 seconds: 19, last successful checkin: 0 seconds ago\nservice: logd, total successful checkins in 198 seconds: 19, last successful checkin: 0 seconds ago\nservice: thermalmonitord (2 induced crashes), no successful checkins in 198 seconds\nservice: runningboardd, total successful checkins in 198 seconds: 19, last successful checkin: 0 seconds ago\nservice: wifid, total successful checkins in 198 seconds: 19, last successful checkin: 0 seconds ago\nservice: configd, total successful checkins in 198 seconds: 19, last successful checkin: 0 seconds ago\nservice: CommCenter, total successful checkins in 198 seconds: 18, last successful checkin: 0 seconds ago\n\nDebugger message: panic\nMemory ID: 0x1\nOS release type: User\nOS version: 22D72\nKernel version: Darwin Kernel Version 24.3.0: Thu Jan 16 02:59:12 PST 2025; root:xnu-11215.82.4~20\/RELEASE_ARM64_T8020\nFileset Kernelcache UUID: EE705F7302DD006CD06FA9E237658DE4\nKernel UUID: F28D3A62-E2FD-3E12-8694-E1F67C905021\nBoot session UUID: 91E7B75A-E7F8-4C43-8A0C-A9B4F3457D5A\niBoot version: iBoot-11881.80.57\nsecure boot?: YES\nroots installed: 0\nPaniclog version: 14\nKernelCache slide: 0x000000001cd60000\nKernelCache base: 0xfffffff023d64000\nKernel slide: 0x000000001cd68000\nKernel text base: 0xfffffff023d6c000\nKernel text exec slide: 0x000000001db2c000\nKernel text exec base: 0xfffffff024b30000\nmach_absolute_time: 0x11b8ecc66\nEpoch Time: sec usec\n Boot : 0x67bb96c5 0x0001baca\n Sleep : 0x67bb992c 0x00001a1c\n Wake : 0x67bb9956 0x000740b4\n Calendar: 0x67bb995d 0x0000a0af\n\nZone info:\n Zone map: 0xffffffdebd864000 - 0xffffffe4bd864000\n . VM : 0xffffffdebd864000 - 0xffffffdfa3ec8000\n . RO : 0xffffffdfa3ec8000 - 0xffffffdff0b94000\n . GEN0 : 0xffffffdff0b94000 - 0xffffffe0d71f8000\n . GEN1 : 0xffffffe0d71f8000 - 0xffffffe1bd85c000\n . GEN2 : 0xffffffe1bd85c000 - 0xffffffe2a3ec4000\n . GEN3 : 0xffffffe2a3ec4000 - 0xffffffe38a52c000\n . DATA : 0xffffffe38a52c000 - 0xffffffe4bd864000\n Metadata: 0xffffffe656650000 - 0xffffffe657e50000\n Bitmaps : 0xffffffe657e50000 - 0xffffffe658918000\n Extra : 0 - 0\n\nTPIDRx_ELy = {1: 0xffffffe1be3047a0 0: 0x0000000000000001 0ro: 0x000000016b8db0e0 }\nCORE 0: PC=0xfffffff024cc2c68, LR=0xfffffff024cc2c64, FP=0xffffffef8d203e60\nCORE 1 is the one that panicked. Check the full backtrace for details.\nCORE 2: PC=0xfffffff024cc2c68, LR=0xfffffff024cc2c64, FP=0xffffffef8d383e60\nCORE 3: PC=0xfffffff024cc2c68, LR=0xfffffff024cc2c64, FP=0xffffffef8d263e60\nCORE 4: PC=0xfffffff024cc2c68, LR=0xfffffff024cc2c64, FP=0xffffffef8d323e60\nCORE 5: PC=0xfffffff024cc2c68, LR=0xfffffff024cc2c64, FP=0xffffffef8d5c3e60\nCompressor Info: 6% of compressed pages limit (OK) and 3% of segments limit (OK) with 1 swapfiles and OK swap space\nTotal cpu_usage: 74045088\nThread task pri cpu_usage\n0xffffffe1be3047a0 watchdogd 97 0\n0xffffffe1bdbaf2a0 kernel_task 0 3772145\n0xffffffe1bd911bb0 kernel_task 0 3747146\n0xffffffe1bdbaa260 kernel_task 0 3521270\n0xffffffe1bdbabd20 kernel_task 0 3356895\n\nPanicked task 0xffffffe389c3cd78: 687 pages, 3 threads: pid 59: watchdogd\nPanicked thread: 0xffffffe1be3047a0, backtrace: 0xffffffef8d59f170, tid: 1438\n\t\t lr: 0xfffffff024b7d530 fp: 0xffffffef8d59f1e0\n\t\t lr: 0xfffffff024cc080c fp: 0xffffffef8d59f250\n\t\t lr: 0xfffffff024cbf1d0 fp: 0xffffffef8d59f300\n\t\t lr: 0xfffffff024b37ae8 fp: 0xffffffef8d59f310\n\t\t lr: 0xfffffff024b7cec8 fp: 0xffffffef8d59f6e0\n\t\t lr: 0xfffffff0252d500c fp: 0xffffffef8d59f700\n\t\t lr: 0xfffffff0254d6354 fp: 0xffffffef8d59f720\n\t\t lr: 0xfffffff0254d5724 fp: 0xffffffef8d59f740\n\t\t lr: 0xfffffff0254d44cc fp: 0xffffffef8d59f860\n\t\t lr: 0xfffffff025244858 fp: 0xffffffef8d59f8a0\n\t\t lr: 0xfffffff025244b54 fp: 0xffffffef8d59fa30\n\t\t lr: 0xfffffff024c8e964 fp: 0xffffffef8d59fb50\n\t\t lr: 0xfffffff024b84444 fp: 0xffffffef8d59fbf0\n\t\t lr: 0xfffffff024b5a464 fp: 0xffffffef8d59fc50\n\t\t lr: 0xfffffff024b6efc8 fp: 0xffffffef8d59fcb0\n\t\t lr: 0xfffffff024b6f470 fp: 0xffffffef8d59fdb0\n\t\t lr: 0xfffffff024cb3c50 fp: 0xffffffef8d59fe60\n\t\t lr: 0xfffffff024cbf5e4 fp: 0xffffffef8d59ff10\n\t\t lr: 0xfffffff024b37ae8 fp: 0xffffffef8d59ff20\n Kernel Extensions in backtrace:\n com.apple.driver.AppleARMWatchdogTimer(1.0)[9BE42401-8646-345D-81CA-CC8DD05E17CA]@0xfffffff0254d12f0->0xfffffff0254d6353\n dependency: com.apple.driver.AppleARMPlatform(1.0.2)[69E78B4A-6673-3C59-9DD5-79A01FA700A3]@0xfffffff02547dd50->0xfffffff0254d12e3\n\nlast started kext at 552573213: com.apple.driver.AppleUSBEthernetDevice\t7.0 (addr 0xfffffff0242e5a30, size 4690)\nloaded kexts:\ncom.apple.driver.AppleUSBEthernetDevice\t7.0\ncom.apple.driver.AppleIDAMInterface\t1\ncom.apple.driver.AppleUSBDeviceNCM\t5.0.0\ncom.apple.driver.AppleUSBDeviceMux\t1.0.0d1\ncom.apple.iokit.IOAccessoryPortUSB\t1.0.0\ncom.apple.driver.AppleUSBMike\t1.0.0d1\ncom.apple.driver.AOPTouchKext\t313\ncom.apple.driver.AppleAOPVoiceTrigger\t420.7\ncom.apple.driver.AppleBasebandPCIMAVPDP\t1\ncom.apple.driver.AppleBasebandPCIICEPDP\t1\ncom.apple.driver.AppleEmbeddedGPS\t1.0.0d1\ncom.apple.driver.AppleSMCWirelessCharger\t1.0.1\ncom.apple.driver.ApplePMP\t1\ncom.apple.driver.AppleIDV\t7.300\ncom.apple.AppleFSCompression.AppleFSCompressionTypeZlib\t1.0.0\ncom.apple.nke.......

There is a looot more but its too long for me to post it here.