Display Blanking and Kernel Panic Solved

[forman]

Over the past few days my Power Mac G5 Dual 2 GHz machine has been suffering intermittent kernel panics that were slowly increasing in frequency. The problem manifested itself by the display blanking (as if the computer were going to sleep) and coming back on several times within 15 seconds. The screen would then blank, the kernel would panic, and the fans would go into jet mode.

I ran the hardware diagnostics by putting in the "Mac OS X Install Disc 1" and holding down the Option key. I also fixed permissions on the disk by using "Disk Utility" during longer periods of uptime. No problems were found by "Disk Utility" and the hardware diagnostics (both the standard and extended tests) returned no problems.

After checking the "/Library/Logs/panic.log" file, I found that the kernel panics involved "com.apple.NVDAResman" -- the problem was related to the video card. On a hunch I purchased a can of compressed air, opened up the case, and blew out a very dusty video card. When I restarted, the kernel panics stopped. It appears that the kernel panics were due to a dusty video card (GeForce 6800 Ultra) that was overheating. I just thought I'd share my success story with others.

Included below are my system specifications and the panic.log file.

Michael.

Hardware Overview:

  Machine Name:	Power Mac G5
  Machine Model:	PowerMac7,3
  CPU Type:	PowerPC G5  (3.0)
  Number Of CPUs:	2
  CPU Speed:	2 GHz
  L2 Cache (per CPU):	512 KB
  Memory:	3 GB
  Bus Speed:	1 GHz
  Boot ROM Version:	5.2.4f1

NVIDIA GeForce 6800 Ultra DDL:

  Chipset Model:	GeForce 6800 Ultra
  Type:	Display
  Bus:	AGP
  Slot:	SLOT-1
  VRAM (Total):	256 MB
  Vendor:	nVIDIA (0x10de)
  Device ID:	0x0040
  Revision ID:	0x00a1
  ROM Revision:	2130
  Displays:
Cinema HD Display:
  Display Type:	LCD
  Resolution:	1920 x 1200
  Depth:	32-bit Color
  Core Image:	Supported
  Main Display:	Yes
  Mirror:	Off
  Online:	Yes
  Quartz Extreme:	Supported
Display:
  Online:	No
  Status:	No display connected

*********

Sat Oct 22 09:06:22 2005


Unresolved kernel trap(cpu 0): 0x300 - Data access DAR=0x000000005A6C103E PC=0x0000000000934164
Latest crash info for cpu 0:
   Exception state (sv=0x5A523000)
      PC=0x00934164; MSR=0x00009030; DAR=0x5A6C103E; DSISR=0x42000000; LR=0x009427F4; R1=0x41C7B840; XCP=0x0000000C (0x300 - Data access)
      Backtrace:
0x009427EC 0x0093FF50 0x0093497C 0x00934908 0x0093E188 0x0093DF90
         0x00931D0C 0x00930B38 0x006D99F8 0x006C6BA8 0x006C8C28 0x006B0DF4 0x002E7A98 0x0008C858
         0x000291C0 0x000233AC 0x000ABE2C 0x4E4F4E45
         backtrace terminated - frame not mapped or invalid: 0xBFFF6C60

      Kernel loadable modules in backtrace (with dependencies):
         com.apple.NVDAResman(4.0.6)@0x6d8000
            dependency: com.apple.iokit.IOPCIFamily(1.6)@0x472000
            dependency: com.apple.iokit.IOGraphicsFamily(1.4)@0x69e000
            dependency: com.apple.iokit.IONDRVSupport(1.4)@0x6c2000
         com.apple.iokit.IONDRVSupport(1.4)@0x6c2000
            dependency: com.apple.iokit.IOPCIFamily(1.6)@0x472000
            dependency: com.apple.iokit.IOGraphicsFamily(1.4)@0x69e000
         com.apple.iokit.IOGraphicsFamily(1.4)@0x69e000
            dependency: com.apple.iokit.IOPCIFamily(1.6)@0x472000
Proceeding back via exception chain:
   Exception state (sv=0x5A523000)
      previously dumped as "Latest" state. skipping...
   Exception state (sv=0x5A6B6000)
      PC=0x9000A738; MSR=0x0200F030; DAR=0xE12F2000; DSISR=0x42000000; LR=0x9000A67C; R1=0xBFFF6C60; XCP=0x00000030 (0xC00 - System call)

Kernel version:
Darwin Kernel Version 8.2.0: Fri Jun 24 17:46:54 PDT 2005; root:xnu-792.2.4.obj~3/RELEASE_PPC
panic(cpu 0 caller 0xFFFF0003): 0x300 - Data access
Latest stack backtrace for cpu 0:
      Backtrace:
         0x00095544 0x00095A5C 0x0002683C 0x000A819C 0x000ABB00
Proceeding back via exception chain:
   Exception state (sv=0x5A523000)
      PC=0x00934164; MSR=0x00009030; DAR=0x5A6C103E; DSISR=0x42000000; LR=0x009427F4; R1=0x41C7B840; XCP=0x0000000C (0x300 - Data access)
      Backtrace:
0x009427EC 0x0093FF50 0x0093497C 0x00934908 0x0093E188 0x0093DF90
         0x00931D0C 0x00930B38 0x006D99F8 0x006C6BA8 0x006C8C28 0x006B0DF4 0x002E7A98 0x0008C858
         0x000291C0 0x000233AC 0x000ABE2C 0x4E4F4E45
         backtrace terminated - frame not mapped or invalid: 0xBFFF6C60
*********

[ex2bot]

Wow! I can see how the cheese grater would let in some dust. Sounds like the big fan on the 6800 turned into a vacuum cleaner.

Doug

[fryke]

Any PC housing, doesn't have to be a PowerMac G5, gets dusty on the inside.

[ex2bot]

Tis true.