On Apr 19, 2009, at 3:36 PM, Owen Strawn wrote:
> > > So if I replace it with a known good fan, it might work or it might > not. > > Dang. > > > ----- Original Message ---- > From: Jim Scott <jesco...@gmail.com> > To: imaclist@googlegroups.com > Sent: Sunday, April 19, 2009 4:41:14 PM > Subject: Re: G4 iMac overheating > > > > On Apr 19, 2009, at 2:38 PM, owen wrote: > >> >> If I poke it with a plastic straw from a compressed air can, I can >> get >> a couple of blades before it stops again. If I hit it just as it is >> trying to turn I can get a rev or two. So it's not actually stuck, >> but >> it won't actually run. > > Then it's got to be an electrical issue, either internal or external. > On Apr 19, 2009, at 3:36 PM, Owen Strawn wrote: > > > So if I replace it with a known good fan, it might work or it might > not. > > Dang. Yep. That's why tinkering with Macs is called a hobby. If it works, you get the glory. If it doesn't work, you've eliminated a major source of the problem. Then you've nothing left to do but to do a continuity and impedance test on the three wires from the fan at the connector to their termination in the multiconnector that fits into the connector on the logic board. If the wires are OK all the way to the multiconnector, then the problem lies in the connector and/or circuitry on the logic board. But since the original fan is getting enough juice to make it want to start, my experience suggests that a known-good fan will solve the overheating problem. Then there's experimentation. One trick I use is to put one or two drops of very light oil on the fan's bearing. This usually involves peeling back the label enough to get the oil directly on the bearing and shaft end. I then spin the blades by hand to let the oil work its way in. More often than not, a recalcitrant fan will spring back to life. This can last anywhere from only a short time to indefinitely. Cheers! --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to Low End Mac's iMac List, a group for those using G3, G4, G5, and Intel Core iMacs as well as Apple 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 unsubscribe from this group, send email to imaclist-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/imaclist?hl=en Low End Mac RSS feed at feed://lowendmac.com/feed.xml -~----------~----~----~----~------~----~------~--~---
