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You are here: MacNN Forums > Hardware - Troubleshooting and Discussion > Mac Desktops > Weird screen pattern freezes Intel iMac, can't boot from HDD or DVD

Weird screen pattern freezes Intel iMac, can't boot from HDD or DVD
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dugost
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Aug 23, 2012, 01:16 PM
 
I woke up today to find the screen of my Intel iMac 3.06 Ghz (Snow Leopard, 6 GB RAM) black with a sparse pattern of bright pixels on it. I wasn't able to power down holding the Power buton so I unplugged it and left it for a bit before plugging back in. I was then able reboot without any problems. Then a few hours latter a weird pattern appeared across my screen, kind of rolling, animated in spots as seen here:



I powered down, started it up and the screen had this pattern on it:



It froze during startup at the point shown in the photo with the Apple logo. I powered down, unplugged, plugged back in and then tried booting up from my Snow Leopard install disc. It also froze on the logo screen. Another attempt brought up the "You need to restart your computer…" message in different languages shown here:



I figured it was having a kernel panic so I did some searching around and followed instructions on The X Lab - Resolving Kernel Panics page and Apple's Kernel Panic Troubleshooting page. I unplugged everything but my mouse and keyboard, and tried booting into Safe Mode. The screen still had the same pattern but it froze again during startup, the grey progress bar having disappeared.

I can't boot from my hard drive or from a DVD and the pattern is always on screen when I turn the iMac back on. I can't run Apple Hardware Test. I reset the PRAM. Still unable to boot but the pattern on the screen did change from the mess of b&w squigglies above to vertical bars as shown here:



Trying to boot normally or in Safe Mode both result in the spinning wheel freezing and halting startup.

I found powering down then gets weird. It's like it tries to turn on again but can't after a second. Or sometimes it will and the mouse lights up, I can hear the optical drive but the screen stays dark. At that point I need to unplug and try again.

I tried booting from Snow Leopard install DVD during one of these weird cycles and could hear it trying to access the optical drive but I don't believe it even got to the chime stage.

I attempted booting from the install DVD again after unplugging. No luck there but instead of a frozen spinning wheel, it brings up the "You need to restart message…". Other methods don't do this.

Still at a loss to find a reason for this but it appears to be a hardware problem, no doubt the video card based on the screen issues. The night before any of this happened, I noticed the fan was running when there wasn't really any reason for it. The computer was idle, no major tasks running. I'm wondering if perhaps the videocard overheated and is causing problems. Perhaps the temperature sensors are screwed up?
I'm stuck but I'm wondering if any of this sheds any light on what the problem is or if (even better) someone knows how to fix it.
     
reader50
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Aug 23, 2012, 04:13 PM
 
I edited your post to put the images inline.

Your GPU chip is overheating - the heat sink may have come off, or the HS glue dried up. The heat sink could be reapplied, but the GPU chip is soldered onto the motherboard. If the chip itself is blown, you'd need a motherboard swap.

Based on processor speed and RAM, you have a metal-case iMac between 2008 and 2010. The upper end of that range can still be covered by AppleCare - did you buy that?

Otherwise, I'd recommend a trip to an Apple Store to have a genius look at it.
     
dugost  (op)
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Aug 23, 2012, 05:21 PM
 
Thanks for doing that. The image function for the site wasn't working for me at all on this old machine. But more importantly, thank you for the info! I don't have AppleCare and I don't live in an area with an Apple Store.

I've opened my iMac up in the past to replace a hard drive so I'm confident I can do it again to see if the heat sink has come loose. Is this something I can re-apply myself or will I need to find an Apple-certified tech for something like that?

If it's the GPU chip and the motherboard needs to be swapped out, any idea what something like that runs? Or is it even worth replacing it in a machine that's over 4 years old?

Possibly related, right before the warranty was up I had the screen replaced since it had some problems like burn-in or something. If it's the GPU then I don't imagine the replacement screen is problematic.

This is really crippling me since it's my only work computer so if it's not something I can get done in the next couple of days then I'm probably looking at buying a new machine of some kind.
     
reader50
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Aug 23, 2012, 07:30 PM
 
If you've opened up a metal-body iMac, your tech skills are well above average. That changes the advice a bit.

There's a faint chance the display cable is pinched, but that shouldn't lock up the machine. Check it for the fun of it.

I've never taken apart one of the metal-bodies, so can't say for sure about the heatsink. It's quite likely glued to the GPU with HS grease/glue, and if the glue has dried out, it should come off easily. Generic HS glue ought to work. Check the VRAM chips too, especially if they have their own heat sink.

Blown chips can in theory be replaced using a heat gun. But that's reportedly a tricky job that doesn't always work. Apple keeps replacement motherboard costs high, probably to encourage new computer sales. If you narrow it down to blown chips, I'd suggest checking eBay for a motherboard. Sometimes when the display goes, people part out the rest of the computer rather than repair, so a motherboard might be available.

While you're in there, look for any other damaged components, like swollen electrolytic capacitors near the GPU. It's a long shot - the capacitor plague was a good many years before your iMac was made. But a bad component like that would be comparatively easy to replace.

ps - it would help a little if you could tell us your exact iMac model.
     
Waragainstsleep
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Aug 24, 2012, 12:39 AM
 
It might be the video RAM rather than the GPU itself. The result is the same though. New logic board.

If you could persuade it run a hardware test it might confirm one or the other for you.
I have plenty of more important things to do, if only I could bring myself to do them....
     
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Aug 24, 2012, 04:55 AM
 
While you're in there anyway, make sure to clean out all vents and make sure nothing is restricting airflow. It seems like your problem is heat-related somehow.
The new Mac Pro has up to 30 MB of cache inside the processor itself. That's more than the HD in my first Mac. Somehow I'm still running out of space.
     
dugost  (op)
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Aug 24, 2012, 08:27 AM
 
Originally Posted by reader50 View Post
If you've opened up a metal-body iMac, your tech skills are well above average. That changes the advice a bit.
There's a faint chance the display cable is pinched, but that shouldn't lock up the machine. Check it for the fun of it.
I've never taken apart one of the metal-bodies, so can't say for sure about the heatsink. It's quite likely glued to the GPU with HS grease/glue, and if the glue has dried out, it should come off easily. Generic HS glue ought to work. Check the VRAM chips too, especially if they have their own heat sink.
Blown chips can in theory be replaced using a heat gun. But that's reportedly a tricky job that doesn't always work. Apple keeps replacement motherboard costs high, probably to encourage new computer sales. If you narrow it down to blown chips, I'd suggest checking eBay for a motherboard. Sometimes when the display goes, people part out the rest of the computer rather than repair, so a motherboard might be available.
While you're in there, look for any other damaged components, like swollen electrolytic capacitors near the GPU. It's a long shot - the capacitor plague was a good many years before your iMac was made. But a bad component like that would be comparatively easy to replace.
ps - it would help a little if you could tell us your exact iMac model.
Thank you for all of those suggestions and advice! It's a 24" Intel iMac 3.06 Ghz. I'm going to try and open it up today and check things out inside but I really doubt there will be much I can do unless it's something very obvious like a pinched cable or something's loose. I'm also going to pop out the RAM and install older sticks I think I still have around here. I got a 6 GB kit from OWC that goes 2 GB higher than what Apple lists as the max. I doubt it's RAM but might as well give it a shot.

I'll post any findings or pics of anything suspicious.

I bought a new 27" iMac last night because not having a work machine is costing me money and work. If I can fix my old iMac then I'll have a secondary machine if I need it, or at least something to watch movies on in another room. Haha.
     
dugost  (op)
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Aug 24, 2012, 08:33 AM
 
Originally Posted by Waragainstsleep View Post
It might be the video RAM rather than the GPU itself. The result is the same though. New logic board.
If you could persuade it run a hardware test it might confirm one or the other for you.
Thanks. If it's the logic board then I may look around for a replacement to see if I can have it set up as a secondary machine now that I've got a new iMac on the way.

I tried holding D at startup to run Apple Hardware Test but the machine locks up. I don't see the AHT icon come up. I will be trying it again today though and will post any results if it works.
     
dugost  (op)
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Aug 24, 2012, 08:35 AM
 
Originally Posted by P View Post
While you're in there anyway, make sure to clean out all vents and make sure nothing is restricting airflow. It seems like your problem is heat-related somehow.
Thanks. I'll be sure to clean things out and make sure nothing is blocked. I hope it's something that simple.
     
reader50
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Aug 24, 2012, 11:03 AM
 
Originally Posted by dugost View Post
It's a 24" Intel iMac 3.06 Ghz. ... I got a 6 GB kit from OWC that goes 2 GB higher than what Apple lists as the max.
The model number is printed on the underside of the stand. The info you've given narrows it down to an early 2008 model, or an early 2009 model. I'd still like to know which it is, and you might want to also. The first one supports 6 GB RAM, while the second one goes to 8 GB.

24-inch early 2008 (6 GB max DDR2 so-dimm)
.. order# MB325LL/A {iMac8,1}

24-inch early 2009 (8 GB max DDR3 so-dimm)
.. order# MB420LL/A {iMac9,1}

If you can't find the info, your HD size may identify the model also.

early 2008: 320, 500, 750 GB, 1 TB

early 2009: 640 GB, 1 TB
     
dugost  (op)
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Aug 24, 2012, 10:30 PM
 
Ah, didn't know you needed to be that specific. It's MB325LL/A, early 2008. And I'm actually writing this from the problem machine. Well, formerly problem machine. Everything seems to be working fine now. Woke up to find the screen problem gone and I was able to boot normally…6 hours after ordering a new iMac (of course!).

I haven't had any problems for the past 15 hours or so. I've been able to run TechTools Pro 5, which gave the all clear, boot from the install DVD to run AHT, which also reported no problems in the regular and extended tests, and run Repair Permissions. I have no idea what changed and why I'm having absolutely no problems now after over 2 days of screen issues that were halting reboots.

I submitted a crash report to Apple and have included the text below. I don't know what else to test and I'm reluctant to crack this thing open now in case I do more harm than good.

I could cancel the order for the new but I think maybe I just might play it safe, despite what my bank book says, and upgrade. Although, I might have buyer's remorse if they announce new iMacs with Retina Displays and such this October.


Interval Since Last Panic Report: 30182048 sec
Panics Since Last Report: 1
Anonymous UUID: C2F1C815-EB10-4D22-BCF3-2B7EEC027198

Thu Aug 23 17:28:22 2012
panic(cpu 1 caller 0x2a6ac2): Kernel trap at 0x00000000, type 14=page fault, registers:
CR0: 0x8001003b, CR2: 0x00000000, CR3: 0x00100000, CR4: 0x00000660
EAX: 0x0ae90004, EBX: 0x0ae90004, ECX: 0x00000080, EDX: 0x09abf004
CR2: 0x00000000, EBP: 0x7ed832d8, ESI: 0x09abf004, EDI: 0x0afb0204
EFL: 0x00010206, EIP: 0x00000000, CS: 0x00000008, DS: 0x0ae90010
Error code: 0x00000010

Backtrace (CPU 1), Frame : Return Address (4 potential args on stack)
0x7ed830d8 : 0x21acfa (0x5ce650 0x7ed8310c 0x223156 0x0)
0x7ed83128 : 0x2a6ac2 (0x590a50 0x0 0xe 0x590c1a)
0x7ed83208 : 0x29c968 (0x7ed83220 0x3425 0x7ed832d8 0x0)
0x7ed83218 : 0x0 (0xe 0xafb0048 0x7ed80010 0x7fb20010)
0x7ed832d8 : 0x7fb2398a (0x9abf004 0xae90004 0x7ed83344 0x0)
0x7ed83368 : 0x7fb21ab1 (0x9abf004 0xae90004 0x7ed833a8 0x7fa4ba6f)
0x7ed833a8 : 0x7fb20696 (0x9abf004 0xae90004 0x1 0x0)
0x7ed83438 : 0x7fb00d05 (0x9abf004 0xae90004 0x7ed8347c 0x0)
0x7ed83498 : 0x7fb08e56 (0x9abf004 0x9d8b004 0x10000 0x0)
0x7ed834e8 : 0x7fb0493a (0x7ed83534 0x7fc72a20 0x0 0x0)
0x7ed83508 : 0x7fa4ddc5 (0x7ed83534 0x7ed83554 0x7ed83558 0x7fa1ac7a)
0x7ed83578 : 0x7fa4dee1 (0xc1d0000e 0x1007313 0x730122 0x7ed8388c)
0x7ed835e8 : 0x7fa3cbbe (0xc1d0000e 0x1007313 0x730122 0x7ed8388c)
0x7ed83618 : 0x7fa5d440 (0x7ed837a8 0x6 0x0 0x0)
0x7ed83778 : 0x7fa5ed81 (0x0 0x600d600d 0x702a 0x7ed837a8)
0x7ed83848 : 0x7fc0e990 (0xc1d0000e 0x1007313 0x730122 0x7ed8388c)
0x7ed838b8 : 0x7fc0f0c1 (0x696e4000 0xc1 0x7ed83914 0x7ed83910)
0x7ed83938 : 0x7fc1fa2a (0x696e4000 0x0 0x1007313 0x73)
0x7ed83a48 : 0x7fa035a4 (0x696e4000 0x0 0x7ed83b8a 0x80)
0x7ed83aa8 : 0x7ed8c796 (0xad60000 0x0 0x7ed83b8a 0x80)
Backtrace continues...
Kernel Extensions in backtrace (with dependencies):
com.apple.NVDAResman(6.0.0)@0x7fa00000->0x7fc93fff
dependency: com.apple.iokit.IOPCIFamily(2.6)@0x78233000
dependency: com.apple.iokit.IONDRVSupport(2.0)@0x7ed85000
dependency: com.apple.iokit.IOGraphicsFamily(2.0)@0x7f607000
com.apple.iokit.IONDRVSupport(2.0)@0x7ed85000->0x7ed92fff
dependency: com.apple.iokit.IOGraphicsFamily(2.0)@0x7f607000
dependency: com.apple.iokit.IOPCIFamily(2.6)@0x78233000

BSD process name corresponding to current thread: WindowServer

Mac OS version:
10A432

Kernel version:
Darwin Kernel Version 10.0.0: Fri Jul 31 22:47:34 PDT 2009; root:xnu-1456.1.25~1/RELEASE_I386
System model name: iMac8,1 (Mac-F227BEC8)

System uptime in nanoseconds: 119651542238
unloaded kexts:
(none)
loaded kexts:
com.apple.driver.AppleTyMCEDriver 1.0.1d8
com.apple.driver.InternalModemSupport 2.6.0
com.apple.driver.AppleIntelYonahProfile 14
com.apple.driver.AppleIntelPenrynProfile 17
com.apple.Dont_Steal_Mac_OS_X 7.0.0
com.apple.driver.AppleUpstreamUserClient 3.0.5
com.apple.driver.AppleIntelNehalemProfile 11
com.apple.driver.AudioIPCDriver 1.1.0
com.apple.driver.AppleHDA 1.7.4a1
com.apple.driver.AppleGraphicsControl 2.8.16
com.apple.GeForce 6.0.0
com.apple.driver.AppleLPC 1.4.6
com.apple.driver.AppleIRController 161
com.apple.driver.AppleIntelMeromProfile 19
com.apple.driver.ACPI_SMC_PlatformPlugin 3.4.0a20
com.apple.driver.AppleBacklight 170.0.2
com.apple.driver.AppleHIDKeyboard 1.1.5f1
com.apple.driver.DiskImages.SparseDiskImage 281
com.apple.driver.DiskImages.ReadWriteDiskImage 281
com.apple.driver.DiskImages.UDIFDiskImage 281
com.apple.driver.DiskImages.RAMBackingStore 281
com.apple.driver.DiskImages.HTTPBackingStore 281
com.apple.driver.DiskImages.FileBackingStore 281
com.apple.iokit.SCSITaskUserClient 2.5.0
com.apple.BootCache 31
com.apple.AppleFSCompression.AppleFSCompressionTyp eZlib 1.0.0d1
com.apple.iokit.IOAHCIBlockStorage 1.5.0
com.apple.driver.AppleAHCIPort 2.0.0
com.apple.driver.AppleUSBHub 3.7.8
com.apple.driver.AppleIntelPIIXATA 2.5.0
com.apple.driver.AppleUSBUHCI 3.7.5
com.apple.iokit.AppleYukon2 3.1.14b1
com.apple.driver.AppleUSBEHCI 3.7.5
com.apple.driver.AirPortBrcm43xx 410.91.20
com.apple.driver.AppleFWOHCI 4.3.4
com.apple.driver.AppleEFINVRAM 1.3.0
com.apple.driver.AppleRTC 1.3
com.apple.driver.AppleHPET 1.4
com.apple.driver.AppleACPIButtons 1.3
com.apple.driver.AppleSMBIOS 1.4
com.apple.driver.AppleACPIEC 1.3
com.apple.driver.AppleAPIC 1.4
com.apple.driver.AppleIntelCPUPowerManagementClien t 90.0.0
com.apple.security.sandbox 0
com.apple.security.quarantine 0
com.apple.nke.applicationfirewall 2.0.11
com.apple.driver.AppleIntelCPUPowerManagement 90.0.0
com.apple.driver.AppleHDAPlatformDriver 1.7.4a1 - last loaded 115256241684
com.apple.driver.AppleProfileReadCounterAction 17
com.apple.driver.AppleProfileTimestampAction 10
com.apple.driver.AppleProfileThreadInfoAction 14
com.apple.driver.AppleProfileRegisterStateAction 10
com.apple.driver.AppleProfileKEventAction 10
com.apple.driver.AppleProfileCallstackAction 20
com.apple.iokit.IOSurface 73.0
com.apple.iokit.IOBluetoothSerialManager 2.2f18
com.apple.iokit.IOSerialFamily 10.0.2
com.apple.driver.AppleHDAHardwareConfigDriver 1.7.4a1
com.apple.driver.DspFuncLib 1.7.4a1
com.apple.iokit.IOAudioFamily 1.7.0fc16
com.apple.kext.OSvKernDSPLib 1.3
com.apple.iokit.IOFireWireIP 2.0.3
com.apple.iokit.AppleProfileFamily 40
com.apple.driver.AppleHDAController 1.7.4a1
com.apple.iokit.IOHDAFamily 1.7.4a1
com.apple.driver.AppleSMC 3.0.1d2
com.apple.driver.IOPlatformPluginFamily 3.4.0a20
com.apple.nvidia.nv50hal 6.0.0
com.apple.NVDAResman 6.0.0
com.apple.iokit.IONDRVSupport 2.0
com.apple.iokit.IOGraphicsFamily 2.0
com.apple.driver.AppleBluetoothHIDMouse 1.3.0f1
com.apple.driver.AppleHIDMouse 1.3.0f1
com.apple.driver.IOBluetoothHIDDriver 2.2f18
com.apple.driver.DiskImages.KernelBacked 281
com.apple.iokit.IOUSBHIDDriver 3.7.5
com.apple.driver.BroadcomUSBBluetoothHCIController 2.2f18
com.apple.driver.AppleUSBBluetoothHCIController 2.2f18
com.apple.iokit.IOBluetoothFamily 2.2f18
com.apple.driver.AppleUSBMergeNub 3.7.5
com.apple.driver.AppleUSBComposite 3.7.5
com.apple.iokit.IOSCSIMultimediaCommandsDevice 2.5.0
com.apple.iokit.IOBDStorageFamily 1.6
com.apple.iokit.IODVDStorageFamily 1.6
com.apple.iokit.IOCDStorageFamily 1.6
com.apple.driver.XsanFilter 402.1
com.apple.driver.AppleFileSystemDriver 2.0
com.apple.iokit.IOATAPIProtocolTransport 2.5.0
com.apple.iokit.IOSCSIArchitectureModelFamily 2.5.0
com.apple.iokit.IOAHCIFamily 2.0.0
com.apple.iokit.IOUSBUserClient 3.7.5
com.apple.iokit.IOATAFamily 2.5.0
com.apple.iokit.IOUSBFamily 3.7.8
com.apple.iokit.IO80211Family 300.20
com.apple.iokit.IONetworkingFamily 1.8
com.apple.iokit.IOFireWireFamily 4.1.7
com.apple.driver.AppleEFIRuntime 1.3.0
com.apple.iokit.IOHIDFamily 1.6.0
com.apple.iokit.IOSMBusFamily 1.1
com.apple.security.TMSafetyNet 6
com.apple.kext.AppleMatch 1.0.0d1
com.apple.driver.DiskImages 281
com.apple.iokit.IOStorageFamily 1.6
com.apple.driver.AppleACPIPlatform 1.3
com.apple.iokit.IOPCIFamily 2.6
com.apple.iokit.IOACPIFamily 1.3.0
Model: iMac8,1, BootROM IM81.00C1.B00, 2 processors, Intel Core 2 Duo, 3.06 GHz, 6 GB, SMC 1.30f1
Graphics: NVIDIA GeForce 8800 GS, NVIDIA GeForce 8800 GS, PCIe, 512 MB
Memory Module: global_name
AirPort: spairport_wireless_card_type_airport_extreme (0x14E4, 0x8C), Broadcom BCM43xx 1.0 (5.10.131.42.4)
Bluetooth: Version 2.4.5f3, 2 service, 19 devices, 1 incoming serial ports
Network Service: AirPort, AirPort, en1
Serial ATA Device: WDC WD10EADS-65P6B0, 931.51 GB
Parallel ATA Device: MATSHITADVD-R UJ-875
USB Device: LaCie Hard Drive USB, 0x059f (LaCie), 0x1018, 0xfa400000 / 2
USB Device: Built-in iSight, 0x05ac (Apple Inc.), 0x8502, 0xfd400000 / 2
USB Device: BRCM2046 Hub, 0x0a5c (Broadcom Corp.), 0x4500, 0x1a100000 / 2
USB Device: Bluetooth USB Host Controller, 0x05ac (Apple Inc.), 0x820f, 0x1a110000 / 5
USB Device: IR Receiver, 0x05ac (Apple Inc.), 0x8242, 0x5d100000 / 2
     
Waragainstsleep
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Aug 25, 2012, 02:31 AM
 
Definitely the GPU. I think the upgrade is probably not a bad idea. The GPU will almost certainly get worse over time from now on and I don't think we'll see retina iMacs on the next revision because those panels are still very expensive.
I have plenty of more important things to do, if only I could bring myself to do them....
     
what-a-day
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Aug 25, 2012, 05:11 AM
 
Should the screen come back like before, connect to an external monitor. If the external monitor looks good then it is the screen, if the screen is also bad then you will need a new board.
     
dugost  (op)
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Aug 26, 2012, 11:55 AM
 
Thanks, Waragainstsleep. After the new iMac arrives and I get things migrated over, I'm going to crack my old one open to see if I can fix it or find replacement parts. I think it's still worth trying to save as long as it doesn't cost me an arm and a leg to fix. I just need to get back up and running so I can get some work done, and having a working backup machine will be good.

what-a-day, the screen problems have definitely come back but in a different way. I only seem to get flickering and messed up graphics after I've logged in. Sometimes it happens right away, other times I can go for hours before problems arise. I'm guessing my new 27" iMac can be used as a monitor so I'll give your suggestion a try. Thanks.
     
Waragainstsleep
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Aug 26, 2012, 01:51 PM
 
If the external display (and the new 27" will only run as a thunderbolt display) has no issues while the internal one does, then the internal display is faulty and you shouldn't need a new logic board. I have seen both fail simultaneously before but its rare.
I have plenty of more important things to do, if only I could bring myself to do them....
     
dugost  (op)
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Aug 26, 2012, 02:23 PM
 
Originally Posted by Waragainstsleep View Post
If the external display (and the new 27" will only run as a thunderbolt display) has no issues while the internal one does, then the internal display is faulty and you shouldn't need a new logic board. I have seen both fail simultaneously before but its rare.
Ah, yes. I guess I can't use it as an external monitor for my old iMac. Oh, well, I can find a separate monitor to test things. I had the screen replaced before actually when it was still under warranty. I don't like the idea of replacing either because I'm sure neither would be cheap, but the screen would likely be much easier to replace.
     
Waragainstsleep
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Aug 27, 2012, 06:57 AM
 
Correct. Logic boards in iMacs are kind of a PITA.
I have plenty of more important things to do, if only I could bring myself to do them....
     
B3NN3TT
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Sep 3, 2012, 04:28 AM
 
I'm having VERY SIMILAR symptoms on my 2006 MacPro. Being a tower configuration, is this something I could alleviate with just a new video card swap?
Andy • www.B3NN3TT.com
MacBook Pro 2.8 i7
MacPro 2.66 Quad Xeon
Mac Mini 1.83 Core 2 Duo
     
P
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Sep 3, 2012, 07:22 AM
 
Probably, yes.
The new Mac Pro has up to 30 MB of cache inside the processor itself. That's more than the HD in my first Mac. Somehow I'm still running out of space.
     
shifuimam
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Join Date: Aug 2006
Location: The deep backwoods of the PNW
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Sep 6, 2012, 07:32 AM
 
I realize it's too late now, but why didn't you look into just replacing the video card? Intel iMacs all have GPUs that are separate from the motherboard. They go into a proprietary modified version of a PCI-e slot. A quick eBay search indicates you could have gotten a replacement for under $300, which is a hell of a lot cheaper than a new iMac...
Sell or send me your vintage Mac things if you don't want them.
     
dugost  (op)
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Sep 9, 2012, 08:13 AM
 
Originally Posted by shifuimam View Post
I realize it's too late now, but why didn't you look into just replacing the video card? Intel iMacs all have GPUs that are separate from the motherboard. They go into a proprietary modified version of a PCI-e slot. A quick eBay search indicates you could have gotten a replacement for under $300, which is a hell of a lot cheaper than a new iMac...
Not much I can do about it now, I guess. In a way, I've been itching to upgrade for a while anyway but I never like being forced to do it and losing work time over it. It was sounding like replacing the GPU was going to be beyond my skill level and I didn't have time to troubleshoot things as much as I would have liked. But knowing I can swap out a bad video card easily and relatively cheaply might mean I end up with a usable second machine for work. This could be quite handy so thanks for the info!
     
B3NN3TT
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Join Date: Dec 2009
Location: Columbus, OH
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Nov 21, 2012, 12:49 PM
 
Follow-up from here - new video card fixed the issues on the Mac Pro. Up and humming again with an upgraded card. Thanks for the info!
Andy • www.B3NN3TT.com
MacBook Pro 2.8 i7
MacPro 2.66 Quad Xeon
Mac Mini 1.83 Core 2 Duo
     
Waragainstsleep
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Join Date: Mar 2004
Location: UK
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Nov 22, 2012, 10:58 AM
 
We're glad to hear it. Congrats.
I have plenty of more important things to do, if only I could bring myself to do them....
     
   
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