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Special Report: Troubleshooting the PowerBook G4 15" (FireWire 800); screen spots and more

Special Report: Troubleshooting the PowerBook G4 15" (FireWire 800); screen spots and more

Covering the following and other issues (with new information about screen problems):


New FireWire target mode feature

MacFixIt reader John Wolf notes an interesting new feature on the PowerBook G4 15" (FireWire 800), and possibly other models, where FireWire target disk mode can see what is in the optical drive:

"I accidentally fired up a 15" PowerBook G4 (FireWire 800) in target disk mode with a CD in the drive, and both partitions on the laptop hard drive showed up, as well as the CD in the laptop.

"Ejecting the CD from the host computer works as expected, the CD is spit out. I had hoped that disc burner would see a blank CD when inserted, however, it just comes up with the "There are no volumes readable by OSX" when you try it. Apple System Profiler quits unexpectedly if there is a CD in the TDM laptop, so I couldn't figure out if it sees it as a HD volume, or as some form of Firewire to IDE bridge for the DVD drive. My guess is the former.

"It may not have broad appeal, but it could serve as an emergency CD drive, or maybe a DVD drive to another computer that doesn't have one."

Retrospect Problems

We've now received separate, confirmed reports of Retrospect's inability to properly configure itself for operation with the PowerBook G4 15" (FireWire 800)'s internal SuperDrive.

This problem is not only forcing PowerBook G4 15" owners to seek alternative backup methods, but is also causing wasted CD media because the "test" procedure repeatedly fails. Garth Gaudry writes:


"I tried to configure it using the Retrospect 5.1 in-built configuration procedure. It did the test 'write' on a blank CD and then froze with a message saying 'insert CD when needed.' I left it for many hours and the freeze continued. I've wasted 4 blanks so far reproducing the problem."

"I contacted Retrospect help by e-mail several times and got either no answer or unsatisfactory answers such as 'this must mean that the drive is unsupported.' The Retrospect agent in Australia told me that Dantz's approach in 5.1 is that they do not authenticate individual drives because Retrospect is now designed to configure them automatically."

Note that Retrospect also has several known issues with Mac OS X 10.3 (Panther).

The White Spot issue

For those who haven't been affected (some estimates from resellers peg the the number of defective screens at around 25 percent of shipping units), the "white spot" issue - where small blotches appear on the screen in generally specific areas - has generated serious concern for PowerBook G4 15" (FireWire 800) owners, and headaches for authorized Apple repair centers.

Where the spots appear After posting a 15" Desktop picture that "maps" out five such spots on one user's screen, the overwhelming majority of users who have contacted us confirm that although they may have anywhere from one to all of the spots shown in the picture, and the spots may vary in size relative to those shown, the locations of the spots match up perfectly.

Although we have received a few reports of screens that showed these spots right out of the box, in the vast majority of cases the screen looked fine at first, but gradually developed the spots over a period of a few days to a few weeks.

Casting doubt on the theory that the spotty laptops may have come from a limited production run is the variance in "demographics" across the problematic units. Spots have been reported on both stock and build-to-order units. They have been reported by users who received their laptops on the first day they were available, as well as by people who have received theirs just few days ago. They have been reported by users in Hong Kong, Australia, Boston, Southern California, and many other locations. Sources include local retailers and Apple Stores, mail order vendors, and the Apple Store Online. These varying dates, locations, and sources would seem to rule out any geographic or production concentration. Finally, users who have had their entire laptop replaced (not just repaired) report that the problem often appears on the replacement after a short period of time. (One user, whose pictures we linked to, purchased a unit in New Jersey in September, and later had it replaced in Malaysia -- both units had the same issue.)

Possible causes Though heat was identified as a possible cause originally, most experts now agree that there is some sort of unnecessary pressure on the screen that is causing the spots.

One MacFixIt reader pointed out that "if you take your finger and drag it firm, but lightly across the center of the back of the screen, you will get ripples in the white spot areas." An Authorized Apple Reseller commented that some of the new 15" PowerBooks have "obvious external distortion on the back of the lid." Another reader postulated that perhaps the PowerBook's keyboard isn't entirely flat, and that "bumps" in the keyboard are pressing on the front of the display, causing the spots to form.

It should be noted that although the vast majority of reports of this issue come from owners of the new 15" PowerBook G4, we've received a few individual reports of similar screen problems on older models, such as the 12" PowerBook G4, iBook 800MHz, iBook 600MHz (both 12" and 14"), PowerBook G3 (Pismo), and a few different versions of the PowerBook G4 Titanium (including a number of instances from one reseller). However, one thing that sets these reports apart from the issues with the new 15" PowerBook G4 is that in these reports, the problem took much longer to appear -- after a period of months, or even years. To add to that, reader Steven Joniak reports seeing similar "spots" on IBM, Dell, and Toshiba laptops, and that "the spots show up in about the same areas"; Garth Gillespie reports seeing the same kind of problem on an LCD monitor used for trade shows that got its share of physical abuse; and Jerry Jividen has a similar problem on his 22" Apple Cinema Display. So it appears that this problem is not necessarily isolated to the new 15" PowerBook, but is instead a potential problem with LCD displays in general.

So why is the problem so common in the new 15" PowerBook, and why does it happen so quickly? Although we can't say with certainty, if you put these factors together -- that the cause is most likely pressure, that "spotting" seems to occur on LCD displays in general when under stress, that the screen on the Aluminum 15" PowerBook appears to be more flexible than the screen on the Titanium 15" model -- a believable conclusion is that the screen casing on the new 15" PowerBook is less rigid or otherwise less protective than that of the previous generation of 15" PowerBooks, and that something, either in the screen enclosure itself or from the bottom of the laptop, is putting pressure on the screen.

Reader David Kirkpatrick put it this way: "The white blotch problem is therefore not due to technology specific to this generation of Powerbooks, but must be inherent in the LCD screen assembly itself. The frequency at which this problem is showing up, compared to previous PBs, indicates that some alteration in the way that the screen is assembled has led to the problem. Hopefully Apple will identify the specific cause and correct the design."

Apparently supporting this theory, we received a detailed report from an Apple Authorized Reseller who has seen the problem on a large number of units. He has seen it on a few older 15" Titanium PowerBooks when the screen is stressed continually, but also on the newer units with very little screen stress. His theory is that the issue is related to a combination of poor lid design and poor handling. He provided a number of specific examples of laptop user "abuse" that resulted in pressure being placed on specific points on the screen; "white blotches" at those points were the result. His conclusion is that a stronger and more protective lid design might have prevented this problem from being so prevalent.

Mark O'Neill's concave screen hypothesis:

"When I close and latch the screen on my PowerBook, I notice that the corners of the housing sit about .5 mm higher than at the center section where the latch is located. I was curious to see if this had a 'physical' effect on the screen, I placed a straight edged ruler along the back of the screen housing near the top/front edge and noticed that the housing was just a 'tiny bit' concave. I repeated this same 'test' with the lid open to see if maybe 'pressure' from the latch mechanism was causing this 'deformity'. In the second 'test', I found the lid to be 'deformed' in the same way. However, I did notice that as I moved the ruler further back toward the rear/bottom of the display that the 'deformity' became considerably less pronounced ? almost to the point of where the screen housing appears to be perfectly flat.

"So now the theories: Is it possible that the aluminum screen housing was manufactured with this 'concave feature' intentionally so as to keep the screen from touching the key tops and marking the screen (as was the case with the Lombard G3)? Is there some sort of 'stiffening device' built into the lid to force it into this 'concave shape'? Is the latch mechanism forcing this deformity? In any of these cases, is this 'deformity' placing pressure on the back of the screen and causing the white spots to appear as they would if you were to place pressure in the back of your screen with your finger tips? I've posted a link to photos of these measurements here:"

Apple Response? Apple has yet to provide any official statement or documentation of the white spot issue. However, a good number of readers report that Apple has replaced their PowerBooks due to these spots, indicating that Apple is aware of the problem. In fact, two MacFixIt readers provided us with information about "internal" Apple Knowledge Base articles that were allegedly available to the public -- unintentionally -- a few weeks ago. Although we cannot verify their authenticity, one of the articles we were forwarded mentioned that "PowerBook G4 (15-inch FW 800) computers are being captured if the display pools or has white spots."

The new screens It appears that Apple has changed the screen architecture slightly on some of the replacement PowerBooks that are shipping to customers who were affected by the white spot issue.

Most reports indicate that the new display lid is somewhat heftier and can withstand more force without generating the traditional LCD "ripple" effect. Apple also appears to have included a new latching mechanism.

Some users (for no apparent reason) also report getting new hard drives in their repaired PowerBooks, or in some cases, completely new units.]

It is worth noting, however, that units are still shipping with the problem, and there is virtually no way to determine whether or not you have an affected PowerBook immediately. As stated previously, the problem can crop up after a few days, or a few months depending on unknown factors.

You may want to check the build date on the unit you are purchasing, but there is no definitive date past which no defective displays are included with the 15" PowerBook G4 (FireWire 800).

Screen dimness; illumination problems

Separate from the "white spot" defect, several PowerBook G4 15" (FireWire 800) owners have reported problems with screen illumination.

Most reports are that one side of the screen, or the corners of the screen, gradually become dimmer than the rest of the display area. The problem appears to get worse with time, as some users can - at first - only notice the dimness with a solid, light color (such as the Mac OS X startup screen).

In previous cases of dim screens on Titanium PowerBooks, there was usually a problem with the inverter board - a component of the logic board, the logic board itself, or a pinched/damaged cable. Interestingly, several of the reports detailing PowerBook G4 15" (FireWire 800) screen dimness indicate that the problem only happens at certain room temperatures - with added heat helping to eliminate the dim spots.

Also, some readers have found that setting their PowerBook's display to maximum brightness is the only way to make all areas of the screen properly illuminated. Any other setting - even one notch from the top - will make the dim areas reappear.

In any event, users have found that sending their PowerBook in for repair has positive results.

Bad RAM and replacement

Bad RAM We are receiving a surprisingly high number of "bad RAM" reports from PowerBook G4 15" (FireWire 800) owners after yesterday's postulation that the new PowerBooks might be especially sensitive to faulty memory.

MacFixIt reader George writes "I bought a 15" PowerBook G4 1.25 GHz from J and R in New York, and they agreed to match MacConnection's offer of a RAM upgrade. But, when I got the machine and installed the 2 512 MB cards, the machine would have kernel panics, and I would be forced to restart. I tried Apple's Hardware test CD 4 times, and everything came up clean. I called Apple, and read the logs to the tech support fellow, and it was determined that bad RAM was the cause of my problems. He suggested removing a card, and trying each card separately. I did so, and found that one card seemed to work fine, but my computer wouldn't even finish booting with the other. So, I sent the bad RAM (made by PNY) back to J and R, and ordered a new one from Crucial."

As stated earlier this week, sometimes RAM that appears fine to Hardware Test is still defective. This is rare, but it certainly does happen. The most foolproof way to figure out if bad RAM is a cause of problems is of course to remove RAM (replacing it with known good RAM, if necessary) and see if the problem goes away. That being said, the Hardware Test CD is a quick and easy "first step" to take.

Unfortunately, it appears that Apple semi-frequently ships Macs with at least somewhat defective RAM modules. Apple does not disclose its component suppliers.

Meanwhile, some RAM suppliers are blaming the problem on misinformation from Apple. One reader received this response from reseller OWC:

"We have discovered what has been plaguing the Memory world on the new Aluminum 15" and 17" PowerBooks. It seems Apple failed to express a set of code that was needed on the memory chips for the new Aluminum 15" and 17" PowerBooks. Apple has since revealed what was missing and we have had a new batch of memory Specially designed for the Aluminum 15" and 17". It normally costs more than the memory you purchased but I can upgrade you at no additional cost and ship it our right away. Please let me know if you want this new High Performance Memory for your PowerBooks."

The safest course of action is to order memory from a reputable, established manufacturer, to which you will be able to return a faulty module.

Loose AirPort card can cause startup crashes

We previously reported that a loosely seated AirPort card can cause reception problems. Now Gregory La Vardera reports that a similar problem was causing startup issues with his PowerBook G4 12", and was resolved by simply tightening the card's fit:

"I was having persistent crashes on bootup with my 12" PowerBook G4. When I started troubleshooting it following a deadline I discovered that my airport card was partially dislodged and this was the source of my problem. Right now it is waking from sleep properly as well, but I want to run some more trials with this before I am confident that is resolved. The crash on start is definitely resolved."

Other reports have indicated that this workaround solved a similar issue with the PowerBook G4 15" (FireWire 800).

Startup disc problems

Readers report problems booting from both the TechTool Deluxe and DiskWarrior startup CDs with the PowerBook G4 15" (FireWire 800). These utilities can still be used if a different drive is designated as the startup volume.

One admittedly cumbersome wokraround is to attach your PowerBook G4 to a computer that can boot from the DiskWarrior CD, and put it in FireWire target disk mode. The volume can then be opened and optimized as normal.

  • New FireWire target mode f...
  • Retrospect Problems
  • The White Spot issue
  • Screen dimness; illuminati...
  • Bad RAM and replacement
  • Loose AirPort card can cau...
  • Startup disc problems
  • New FireWire target mode feature
  • Retrospect Problems
  • known issues
  • The White Spot issue
  • 15" Desktop picture
  • linked to
  • Screen dimness; illumination problems
  • Bad RAM and replacement
  • semi-frequently
  • OWC
  • Loose AirPort card can cause startup crashes
  • Startup disc problems
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