On Jul 28, 2011, at 7:49 AM, Deiniol ap Deiniol wrote: > >> After the third Return, the iBook may well chime and restart. If not, try >> the same procedure while putting some pressure on the case in the lower left >> corner of the keyboard (to see the video chip has broken solder joints). If >> after several attempts the screen doesn't light up or you get no chime, yep, >> the logic board's toast. But if you get a chime and hear hard drive >> activity, you may be looking at a broken LVDS or inverter cable, so wiggle >> the screen open and closed to see if that gets anything going. > > No change after trying this a couple of times. > I haven't tried the 'pressure application' ye. I will try this > tomorrow when I getr back from work.t
All of the manipulations, keyboard commands and "tricks" I mentioned are what I use to determine whether a 'Book has the dreaded "loose" video chip problem. White G3 iBooks, G4 iBooks and some G4 PowerBooks tend to develop broken solder joints. They are surface mounted to the logic board using about 500 tiny little solder balls. Such a technique is called BGA for ball grid array. The footprint of each joint is smaller than a dot made by pencil on paper. So it doesn't take much in the way of board flex combined with faulty/poor solder and many, many heat/cool cycles before one of the aforementioned 'Books develops a crack in one or more solder joints. Vast amounts of 700-900 MHz white G3 iBooks have had this problem, largely because the video chip is on the bottom side of the logic board with nothing more than a thick thermal pad to "clamp" it in place. Those G3 iBook cases, frames and screws don't stay very well torqued together, and the result is loose screws, cracked cases and often broken frames as the laptops are used and moved about. Thus enter board flex and loose solder joints. For some reason -- I suspect better solder and better soldering -- first-generation 500 and 600 MHz white iBooks have much lower BGA video chip failure rates, in my experience. G4 iBooks have a different design where the cpu, Northbridge chip and video chip are on the top of the logic board in more or less a row where they are physically clamped to the logic board by a sturdy heat sink. However, the clamping studs and screws also loosen over time and the same broken solder joint phenomenon occurs with G4 iBook video chips. For a long time, it was thought that G4 iBooks were immune to the G3 iBook loose video chip problem, but I think that was because the heat sink clamping force was preventing early failures. Interestingly, the last four iBooks I have worked on all have exhibited video problems similar to those you have described, which means Apple's redesign of the case, frame and addition of a clamped heat sink merely delayed the onset of loose video chips in G4 iBooks. The case design is the enemy. There are too many screws, most of which loosen over time as a result of vibration and use, and those screws are the only means of assuring a rigid and stable platform for the logic board. Every iBook I work on has a bunch of loose screws that used to hold the logic board tight to the skinny frame. Note that Apple's current portable devices are fairly rigid "Unibody" units milled from solid aluminum or plastic, with very few screws. Apple still uses surface mount BGA attachment technology, but the current case designs are so rigid that I seriously doubt MacBooks will have loose video chips as the years pass, at least not from case/board flex. My advice to clients whose iBooks have developed the video chip problem is to not pour any more money into their machines. New logic boards are rare and pricey; used ones that still work will develop the same problem sooner or later. And, most importantly, even the late-2005 end-of-the-line G4 iBooks are quickly becoming marginal performers that are too pokey to provide snappy performance. Besides, they can't run either Snow Leopard or Lion. > > If I can't get it to go I'll see if she wants to sell the rather nice > Power Siupply, which I assume will be OK for my two G3 Powerbooks.? I > haven't put my multimeter across it yet, but it seems to be the same > size chunky connector. An iBook G4 AC adapter will work with all white G3 and G4 iBooks, and with all G4 PowerBooks. But the barrel size of the adapter is smaller than the ones used by G3 PowerBooks and the clamshell G3 iBooks. Newer MacBooks, of course, use the MagSafe AC adapter, a totally different design. Jim Scott -- You received this message because you are a member of G-Group, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/g3-5-list
