The Mother Board

note: same results using Safari.....no crashes so far after Chrome update
log after Google Chrome update:
Description: Kernel log
Size: 10 KB
Last Modified: 1/15/15 9:04 AM
Location: /var/log/kernel.log
Recent Contents: Jan 15 03:40:01 Macs-iMac newsyslog[854]: logfile turned over due to size>1000K
Jan 15 03:40:10 Macs-iMac kernel[0]: Auth result for: e8:fc:af:a6:3b:9d MAC AUTH succeeded
Jan 15 03:40:10 Macs-iMac kernel[0]: Auth result for: e8:fc:af:a6:3b:9d Unsolicited Auth
Jan 15 03:40:10 Macs-iMac kernel[0]: AirPort: Link Up on en1
Jan 15 03:40:10 Macs-iMac kernel[0]: AirPort: RSN handshake complete on en1
Jan 15 03:40:50 Macs-iMac kernel[0]: PM notification timeout (pid 270, Google Chrome He)
Jan 15 03:40:50 Macs-iMac kernel[0]: AirPort: Link Down on en1. Reason 8 (Disassociated because station leaving).
Jan 15 03:40:50 Macs-iMac kernel[0]: System Sleep
Jan 15 06:40:07 Macs-iMac kernel[0]: Wake reason = UHC1
Jan 15 06:40:07 Macs-iMac kernel[0]: System Wake
Jan 15 06:40:07 Macs-iMac kernel[0]: Previous Sleep Cause: 0
Jan 15 06:40:07 Macs-iMac kernel[0]: The USB device Logitech USB Keyboard (Port 1 of Hub at 0x1d000000) may have caused a wake by issuing a remote wakeup (2)
Jan 15 06:40:14 Macs-iMac kernel[0]: Auth result for: e8:fc:af:a6:3b:9d MAC AUTH succeeded
Jan 15 06:40:14 Macs-iMac kernel[0]: Auth result for: e8:fc:af:a6:3b:9d Unsolicited Auth
Jan 15 06:40:15: --- last message repeated 1 time ---
Jan 15 06:40:14 Macs-iMac kernel[0]: AirPort: Link Up on en1
Jan 15 06:40:14 Macs-iMac kernel[0]: AirPort: RSN handshake complete on en1
Jan 15 06:41:07 Macs-iMac kernel[0]: USBF: 24212.125 [0x69e2d00] The IOUSBFamily is having trouble enumerating a USB device that has been plugged in. It will keep retrying. (Port 2 of Hub at 0x1a000000)
Jan 15 06:41:22 Macs-iMac kernel[0]: USB Optical Mouse::terminate(kIOServiceSynchronous) timeout
Jan 15 06:41:22 Macs-iMac kernel[0]: USBF: 24227.924 [0x69e2d00] The IOUSBFamily has successfully enumerated the device.
Jan 15 06:44:37 Macs-iMac kernel[0]: PM notification timeout (pid 270, Google Chrome He)
Jan 15 06:44:38 Macs-iMac kernel[0]: AirPort: Link Down on en1. Reason 8 (Disassociated because station leaving).
Jan 15 06:44:38 Macs-iMac kernel[0]: System Sleep
Jan 15 07:07:46 Macs-iMac kernel[0]: Wake reason = UHC1
Jan 15 07:07:46 Macs-iMac kernel[0]: System Wake
Jan 15 07:07:46 Macs-iMac kernel[0]: Previous Sleep Cause: 0
Jan 15 07:07:46 Macs-iMac kernel[0]: The USB device Logitech USB Keyboard (Port 1 of Hub at 0x1d000000) may have caused a wake by issuing a remote wakeup (2)
Jan 15 07:07:53 Macs-iMac kernel[0]: Auth result for: e8:fc:af:a6:3b:9d MAC AUTH succeeded
Jan 15 07:07:53 Macs-iMac kernel[0]: Auth result for: e8:fc:af:a6:3b:9d Unsolicited Auth
Jan 15 07:07:53 Macs-iMac kernel[0]: AirPort: Link Up on en1
Jan 15 07:07:53 Macs-iMac kernel[0]: AirPort: RSN handshake complete on en1
Jan 15 07:07:55 Macs-iMac kernel[0]: Google Chrome He (map: 0x70887b0) triggered DYLD shared region unnest for map: 0x70887b0, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 07:08:11 Macs-iMac kernel[0]: Google Chrome He (map: 0x7088ae4) triggered DYLD shared region unnest for map: 0x7088ae4, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 07:08:15 Macs-iMac kernel[0]: Google Chrome He (map: 0x70887b0) triggered DYLD shared region unnest for map: 0x70887b0, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 07:12:26 Macs-iMac kernel[0]: Google Chrome He (map: 0x70887b0) triggered DYLD shared region unnest for map: 0x70887b0, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 07:14:24 Macs-iMac kernel[0]: Google Chrome He (map: 0x29fc000) triggered DYLD shared region unnest for map: 0x29fc000, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 07:20:32 Macs-iMac kernel[0]: USBF: 25189.218 [0x69e2d00] The IOUSBFamily is having trouble enumerating a USB device that has been plugged in. It will keep retrying. (Port 2 of Hub at 0x1a000000)
Jan 15 07:20:47 Macs-iMac kernel[0]: USB Optical Mouse::terminate(kIOServiceSynchronous) timeout
Jan 15 07:20:47 Macs-iMac kernel[0]: USBF: 25205. 17 [0x69e2d00] The IOUSBFamily has successfully enumerated the device.
Jan 15 07:21:08 Macs-iMac kernel[0]: Google Chrome He (map: 0x708899c) triggered DYLD shared region unnest for map: 0x708899c, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 07:42:50 Macs-iMac kernel[0]: Google Chrome He (map: 0x70887b0) triggered DYLD shared region unnest for map: 0x70887b0, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 07:49:04 Macs-iMac kernel[0]: PM notification timeout (pid 270, Google Chrome He)
Jan 15 07:49:04 Macs-iMac kernel[0]: AirPort: Link Down on en1. Reason 8 (Disassociated because station leaving).
Jan 15 07:49:04 Macs-iMac kernel[0]: System Sleep
Jan 15 08:48:37 Macs-iMac kernel[0]: Wake reason = UHC4
Jan 15 08:48:37 Macs-iMac kernel[0]: System Wake
Jan 15 08:48:37 Macs-iMac kernel[0]: Previous Sleep Cause: 0
Jan 15 08:48:37 Macs-iMac kernel[0]: The USB device USB Optical Mouse (Port 2 of Hub at 0x1a000000) may have caused a wake by issuing a remote wakeup (2)
Jan 15 08:48:44 Macs-iMac kernel[0]: Auth result for: e8:fc:af:a6:3b:9d MAC AUTH succeeded
Jan 15 08:48:44 Macs-iMac kernel[0]: AirPort: Link Up on en1
Jan 15 08:48:44 Macs-iMac kernel[0]: AirPort: RSN handshake complete on en1
Jan 15 08:48:44 Macs-iMac kernel[0]: Google Chrome He (map: 0x7088000) triggered DYLD shared region unnest for map: 0x7088000, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 08:48:52 Macs-iMac kernel[0]: Google Chrome He (map: 0x70887b0) triggered DYLD shared region unnest for map: 0x70887b0, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 08:48:52 Macs-iMac kernel[0]: Google Chrome He (map: 0x7088ebc) triggered DYLD shared region unnest for map: 0x7088ebc, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 08:50:42 Macs-iMac kernel[0]: USBF: 27026.582 [0x69e2d00] The IOUSBFamily is having trouble enumerating a USB device that has been plugged in. It will keep retrying. (Port 2 of Hub at 0x1a000000)
Jan 15 08:50:57 Macs-iMac kernel[0]: USB Optical Mouse::terminate(kIOServiceSynchronous) timeout
Jan 15 08:50:58 Macs-iMac kernel[0]: USBF: 27042.381 [0x69e2d00] The IOUSBFamily has successfully enumerated the device.
Jan 15 09:01:10 Macs-iMac kernel[0]: Google Chrome He (map: 0x7088ae4) triggered DYLD shared region unnest for map: 0x7088ae4, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 09:01:35 Macs-iMac kernel[0]: Google Chrome He (map: 0x7088b88) triggered DYLD shared region unnest for map: 0x7088b88, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 09:03:45 Macs-iMac kernel[0]: Google Chrome (map: 0x29fc5c4) triggered DYLD shared region unnest for map: 0x29fc5c4, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 09:03:45 Macs-iMac kernel[0]: Google Chrome He (map: 0x11982000) triggered DYLD shared region unnest for map: 0x11982000, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 09:03:46 Macs-iMac kernel[0]: Google Chrome He (map: 0x708847c) triggered DYLD shared region unnest for map: 0x708847c, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 09:03:47 Macs-iMac kernel[0]: Google Chrome He (map: 0x29fc47c) triggered DYLD shared region unnest for map: 0x29fc47c, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 09:03:47 Macs-iMac kernel[0]: Google Chrome He (map: 0x701db88) triggered DYLD shared region unnest for map: 0x701db88, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 09:03:48 Macs-iMac kernel[0]: Google Chrome He (map: 0x7088ebc) triggered DYLD shared region unnest for map: 0x7088ebc, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 09:03:48 Macs-iMac kernel[0]: Google Chrome He (map: 0x7088e18) triggered DYLD shared region unnest for map: 0x7088e18, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.
Jan 15 09:04:04 Macs-iMac kernel[0]: Google Chrome He (map: 0x708899c) triggered DYLD shared region unnest for map: 0x708899c, region 0x7fff88200000->0x7fff88400000. While not abnormal for debuggers, this increases system memory footprint until the target exits.

I bought this system used without OS disc. the AHT Apple Hardware Test link states that for O/S' 10.7 and earlier to run AHT off O/S install disk 2.

found an old usb mouse plugged it in 10 minutes ago and so far so good. I am still going to the electronics store and get a new mouse as well as a matching 2 gig RAM module. Any brand recommendations on RAMM? PC2 DDR 667 SODIMM 2. This is the slowest processor at 2 gHz, and I do not do any gaming or other RAMM demanding tasks. I will follow up when I know more.

Using Crucial's Memory Advisor, they recommend a 4GB kit of DDR3 PC3-8500 NON-ECC 1.35V 256 x 64 or an 8GB Kit of DDR3 PC3-8500 NON-ECC 1.35V 512 x 64.. http://www.crucial.com/usa/en/compatibl ... id-2009%29 and guaranteed compatible.
New Egg has a Corsair 8GBB kit listed.. http://www.newegg.com/ Item#: N82E16820233179
You can go with a higher speed type memory, it will clock back to the bus speed.
If using the on-board video system, a part of main system memory at the top is dedicated to video needs. With low system memory, performance can suffer if the OS does not have sufficient memory for operation. Going above 25% of total system memory for that video "aperture" is not a good idea. If using an add-in video card, all system memory is available.. only a small amount is semi-reserved as a "buffer" for video needs.

I have had no crashes since using this old USB mouse. THANK YOU!
I am going to get a new one anyway. RAMM. It is the stock onboard video card. I also read here: http://lowendmac.com/2007/imac-mid-2007/ in a user comment at the bottom that this system's RAMM limit is 6 gigs.
There are only 2 RAMM slots and as far as I know they do not sell this RAMM in 3 gig increments. Also the user that commented said he runs one 2 gig, and one 4 gig module. That leads me to believe his comment may not be accurate.

That "6 gig limit" on the iMac may refer to a different model than yours. Check that link I found, has three iMac units listed. Each one can take up to 8 gigs of RAM.
To repeat: With memory, a mixed amount should work in single-channel setup. Dual-channel setup requires both channels to have a matched pair of modules for stable operation.
But ensure both modules are exactly the same as to timings, with mixed amounts. If not, then the slower module must be the first detected, to set the proper speed for both modules. If the faster module is first detected, it can overclock the slower module.. and lead to system freezes. This is true of any memory configuration.

As to the mouse having problems, it is not all that hard to splice the cable inside the mouse.
Cut back maybe 6" from the mouse, where conductors are still good. Cut off the cable inside, bare the leads and slip a short length of heat-shrink tube on each, match the wire colors, and do a quick solder job. Then shrink the tubes over the splices.
Should give maybe another two years of use. Or as a backup.

went to link at Crucial site, d/l'ed and ran their memory scanner. http://www.crucial.com/usa/en/scanview/0E1CC67E31D926C3 that scan shows the 2 gig module in the 1st slot. Also, my system model is the mid 2007 with a 2.0 gHz processor. How can I find the specs on the 2 gig module so I can get an exact match? The scan tool just shows the size and location of existing modules, not brand.

Look on ebay for DDR2 (PC2-5300) 667. It apparently takes up to 6Gb, but another 2gb should be safe. I have used bog standard RAM on most of my Macs and it works, even mixing brands. I might be lucky, but hey, it's worth a shot if the price is right.

Check this out on getting to RAM.

CPU-Z is a small, free diagnostics program.. http://www.cpuid.com/softwares.html
But it can show system basics and other details. For memory, the "SPD" tab will show the brand, amount and timings of each module.
Should be a label either on the back or bottom of your iMac. There would be a model number plus other info there to exactly ID your unit.

poundu1, what does clicking the apple icon, about this mac give you for hardware level info? That will tell what series you have and thus what memory limit. I would think your machine has an 8GB limit. It is not too far behind my MacBook pro from late 2009 that is running 8GB.