I've just joined this group as a long term subscriber to the G3-5 list, since I've got an issue with a Late 2006 20" iMac (iMac5,1) which I've been tearing my hair out over for the past few days and I thought I'd throw it to the hive mind after trying every form of disassembly, reassembly, re-thermal-pasting and thermal sensor re- attachment you can imagine...
The machine works fine, but all three fans have gone insane and run at (nearly, but not quite) full speed - around 3800 RPM. All the thermal sensors are giving good, within range readings according to iStat. The last step I tried was AHT, after finding and downloading the correct (3A111) version, which gives me a '4SNS/1/40000000:VGOC' error. I know 4SNS is a sensor error, but I've no idea what the rest of that string means since nobody else on the interwebs seems to have suffered a VGOC error. Resetting the SMC gives a brief respite but within a few minutes of bootup, they've sped back up starting with the HDD bay fan if I follow the speeds of all three. Now I think I've tried pretty much every avenue including the old 'take it apart and put it back together' (I even replaced the thermal compound under all three heatsinks as it looked like a pretty sloppy job) so it may just be a lost cause that needs a new motherboard (and I'd question the economics of that on a 4 year old machine.) Having said that, I thought it was worth asking in case there's anything obvious I've missed, or anybody is able to shed more light on the code AHT is throwing. Another thing I was wondering is whether it's possible to force an EFI Firmware reflash by any means - holding the power button as documented on Apple's website results in a normal boot after a fast flash of the sleep LED and shrill beep - I'm assuming this procedure only works if the firmware is corrupted in the first place... Not that I really think it'll help, but I've got to the point where I'll try anything because its unusably noisy at the moment! Cheers Jason -- You received this message because you are a member of the iMac Group, a group for those using Apple iMacs and eMacs. The list FAQ is at http://lowendmac.com/imac/list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to imaclist@googlegroups.com To leave this group, send email to imaclist+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/imaclist
