iMac restarts by itself

Hi,

I work in a studio with 3 iMacs 1 which is a 27" with the thicker monitor, and 2 which are 27" newer model with a thin monitor (Bought before Mavericks came out). They all seem to be having the same issue. On some days (One iMac every week, or every other week) an iMac just shuts down and restarts without warning.

I've tried resetting the PRAM but the problem still occurs.

I don't recall this issue happening before Mavericks came out, but it could just be a coincidence.

Below is an error report that appeared on the older iMac when it restarted:

Thu Mar 13 14:52:37 2014

panic(cpu 2 caller 0xffffff80036dbe2e): Kernel trap at 0xffffff7f859101e2, type 14=page fault, registers:

CR0: 0x000000008001003b, CR2: 0x000000c700000067, CR3: 0x0000000005f63000, CR4: 0x0000000000000660

RAX: 0xffffff7f859101c4, RBX: 0xffffff8012416400, RCX: 0xffffff7f859103ec, RDX: 0x0000000000000800

RSP: 0xffffff80842d3cc0, RBP: 0xffffff80842d3cf0, RSI: 0xffffff8010636780, RDI: 0xffffff8012416400

R8: 0xffffff8003a16115, R9: 0xffffff80842d3cbc, R10: 0x00000000000003ff, R11: 0xffffffffffffffff

R12: 0xffffff807ecf9900, R13: 0x000000000000003f, R14: 0xffffff800be13b10, R15: 0x000000c700000067

RFL: 0x0000000000010202, RIP: 0xffffff7f859101e2, CS: 0x0000000000000008, SS: 0x0000000000000010

Fault CR2: 0x000000c700000067, Error code: 0x0000000000000000, Fault CPU: 0x2

Backtrace (CPU 2), Frame : Return Address

0xffffff80842d3950 : 0xffffff8003622fa9

0xffffff80842d39d0 : 0xffffff80036dbe2e

0xffffff80842d3ba0 : 0xffffff80036f3326

0xffffff80842d3bc0 : 0xffffff7f859101e2

0xffffff80842d3cf0 : 0xffffff7f8590d22d

0xffffff80842d3fb0 : 0xffffff80036d6ff7

BSD process name corresponding to current thread: kernel_task

Mac OS version:

13C64

Kernel version:

Darwin Kernel Version 13.1.0: Thu Jan 16 19:40:37 PST 2014; root:xnu-2422.90.20~2/RELEASE_X86_64

Kernel UUID: 9FEA8EDC-B629-3ED2-A1A3-6521A1885953

Kernel text base: 0xffffff8003600000

System model name: iMac11,1 (Mac-F2268DAE)

System uptime in nanoseconds: 20436787576710

last loaded kext at 270220869300: com.apple.filesystems.msdosfs

1.9 (addr 0xffffff7f83f54000, size 65536)

loaded kexts:

com.thursby.kext.cifs 11.0.0

com.thursby.kext.NetBIOS

11.0.0

com.apple.filesystems.msdosfs

1.9

com.apple.driver.AudioAUUC

1.60

com.apple.filesystems.monitorfs

1.0

com.apple.driver.AppleBluetoothMultitouch

80.14

com.apple.driver.AppleTyMCEDriver

1.0.2d2

com.apple.driver.AGPM 100.14.15

com.apple.filesystems.autofs

3.0

com.apple.iokit.IOBluetoothSerialManager

4.2.3f10

com.apple.driver.AppleMikeyHIDDriver

124

com.apple.driver.AppleMikeyDriver

2.6.0f1

com.apple.driver.AppleHWSensor

1.9.5d0

com.apple.driver.AppleHDAHardwareConfigDriver

2.6.0f1

com.apple.driver.AppleHDA

2.6.0f1

com.apple.driver.AppleUpstreamUserClient

3.5.13

com.apple.iokit.IOUserEthernet

1.0.0d1

com.apple.kext.AMDFramebuffer

1.2.0

com.apple.ATIRadeonX2000

8.2.4

com.apple.Dont_Steal_Mac_OS_X

7.0.0

com.apple.driver.AppleHWAccess

1

com.apple.driver.ACPI_SMC_PlatformPlugin

1.0.0

com.apple.driver.AppleIntelMCEReporter

104

com.apple.driver.AppleLPC

1.7.0

com.apple.kext.AMD4800Controller

1.2.0

com.apple.iokit.IOBluetoothUSBDFU

4.2.3f10

com.apple.iokit.BroadcomBluetoothHostControllerUSBTransport

4.2.3f10

com.apple.driver.AppleMuxControl

3.4.35

com.apple.driver.AppleBacklight

170.3.5

com.apple.driver.AppleMCCSControl

1.1.12

com.apple.driver.AppleUSBCardReader

3.4.1

com.apple.driver.AppleIRController

325.7

com.apple.driver.AppleFileSystemDriver

3.0.1

com.apple.AppleFSCompression.AppleFSCompressionTypeDataless

1.0.0d1

com.apple.AppleFSCompression.AppleFSCompressionTypeZlib

1.0.0d1

com.apple.BootCache 35

com.apple.iokit.SCSITaskUserClient

3.6.6

com.apple.driver.XsanFilter

404

com.apple.iokit.IOAHCIBlockStorage

2.5.1

com.apple.driver.AppleUSBHub

666.4.0

com.apple.driver.AppleFWOHCI

4.9.9

com.apple.driver.AirPort.Atheros40

700.74.5

com.apple.iokit.AppleBCM5701Ethernet

3.8.1b2

com.apple.driver.AppleAHCIPort

3.0.0

com.apple.driver.AppleUSBEHCI

660.4.0

com.apple.driver.AppleUSBUHCI

656.4.1

com.apple.driver.AppleRTC

2.0

com.apple.driver.AppleACPIButtons

2.0

com.apple.driver.AppleHPET

1.8

com.apple.driver.AppleSMBIOS

2.1

com.apple.driver.AppleACPIEC

2.0

com.apple.driver.AppleAPIC

1.7

com.apple.driver.AppleIntelCPUPowerManagementClient

216.0.0

com.apple.nke.applicationfirewall

153

com.apple.security.quarantine

3

com.apple.driver.AppleIntelCPUPowerManagement

216.0.0

com.apple.driver.AppleBluetoothHIDKeyboard

170.15

com.apple.driver.AppleHIDKeyboard

170.15

com.apple.driver.IOBluetoothHIDDriver

4.2.3f10

com.apple.driver.AppleMultitouchDriver

245.13

com.apple.kext.triggers

1.0

com.apple.iokit.IOSerialFamily

10.0.7

com.apple.driver.DspFuncLib

2.6.0f1

com.apple.vecLib.kext 1.0.0

com.apple.iokit.IOAudioFamily

1.9.5fc2

com.apple.kext.OSvKernDSPLib

1.14

com.apple.iokit.IOSurface

91

com.apple.iokit.IOBluetoothFamily

4.2.3f10

com.apple.driver.AppleHDAController

2.6.0f1

com.apple.iokit.IOHDAFamily

2.6.0f1

com.apple.driver.AppleSMC

3.1.8

com.apple.driver.IOPlatformPluginLegacy

1.0.0

com.apple.driver.AppleSMBusPCI

1.0.12d1

com.apple.driver.IOPlatformPluginFamily

5.7.0d10

com.apple.kext.AMDSupport

1.2.0

com.apple.AppleGraphicsDeviceControl

3.4.35

com.apple.iokit.IOBluetoothHostControllerUSBTransport

4.2.3f10

com.apple.iokit.IOFireWireIP

2.2.6

com.apple.driver.AppleGraphicsControl

3.4.35

com.apple.driver.AppleBacklightExpert

1.0.4

com.apple.iokit.IONDRVSupport

2.4.1

com.apple.driver.AppleSMBusController

1.0.11d1

com.apple.iokit.IOGraphicsFamily

2.4.1

com.apple.iokit.IOSCSIBlockCommandsDevice

3.6.6

com.apple.iokit.IOUSBMassStorageClass

3.6.0

com.apple.iokit.IOUSBHIDDriver

660.4.0

com.apple.driver.AppleUSBMergeNub

650.4.0

com.apple.driver.AppleUSBComposite

656.4.1

com.apple.iokit.IOSCSIMultimediaCommandsDevice

3.6.6

com.apple.iokit.IOBDStorageFamily

1.7

com.apple.iokit.IODVDStorageFamily

1.7.1

com.apple.iokit.IOCDStorageFamily

1.7.1

com.apple.iokit.IOAHCISerialATAPI

2.6.1

com.apple.iokit.IOSCSIArchitectureModelFamily

3.6.6

com.apple.iokit.IOFireWireFamily

4.5.5

com.apple.iokit.IOUSBUserClient

660.4.2

com.apple.iokit.IO80211Family

630.35

com.apple.iokit.IOEthernetAVBController

1.0.3b4

com.apple.driver.mDNSOffloadUserClient

1.0.1b5

com.apple.iokit.IONetworkingFamily

3.2

com.apple.iokit.IOAHCIFamily

2.6.5

com.apple.iokit.IOUSBFamily

675.4.0

com.apple.driver.AppleEFINVRAM

2.0

com.apple.driver.AppleEFIRuntime

2.0

com.apple.iokit.IOHIDFamily

2.0.0

com.apple.iokit.IOSMBusFamily

1.1

com.apple.security.sandbox

278.11

com.apple.kext.AppleMatch

1.0.0d1

com.apple.security.TMSafetyNet

7

com.apple.driver.AppleKeyStore

2

com.apple.driver.DiskImages

371.1

com.apple.iokit.IOStorageFamily

1.9

com.apple.iokit.IOReportFamily

23

com.apple.driver.AppleFDEKeyStore

28.30

com.apple.driver.AppleACPIPlatform

2.0

com.apple.iokit.IOPCIFamily

2.9

com.apple.iokit.IOACPIFamily

1.4

com.apple.kec.corecrypto

1.0

com.apple.kec.pthread 1

Model: iMac11,1, BootROM IM111.0034.B02, 4 processors, Intel Core i5, 2.66 GHz, 4 GB, SMC 1.54f36

Graphics: ATI Radeon HD 4850, ATI Radeon HD 4850, PCIe, 512 MB

Memory Module: BANK 0/DIMM0, 2 GB, DDR3, 1067 MHz, 0x80AD, 0x484D54313235533642465238432D47372020

Memory Module: BANK 1/DIMM0, 2 GB, DDR3, 1067 MHz, 0x80AD, 0x484D54313235533642465238432D47372020

AirPort: spairport_wireless_card_type_airport_extreme (0x168C, 0x8F), Atheros 9280: 4.0.74.0-P2P

Bluetooth: Version 4.2.3f10 13477, 3 services, 23 devices, 1 incoming serial ports

Network Service: Ethernet, Ethernet, en0

Serial ATA Device: ST31000528ASQ, 1 TB

Serial ATA Device: HL-DT-ST DVDRW GA11N

USB Device: Hub

USB Device: Built-in iSight

USB Device: IR Receiver

USB Device: Hub

USB Device: DYMO LabelWriter 450

USB Device: Internal Memory Card Reader

USB Device: BRCM2046 Hub

USB Device: Bluetooth USB Host Controller

Thunderbolt Bus:

Any ideas? All help is appreciated!