Editing PowerBook G4 (section)

===Quality issues===
Some owners have experienced failure of the lower memory slot on some of the 15" models, with the typical repair being the replacement of the logic board. Apple had started a Repair Extension Program concerning the issue,<ref>{{Cite web |title=Official Apple Support |url=http://docs.info.apple.com/article.html?artnum=303173 |url-status=live |archive-url=https://web.archive.org/web/20080507154553/http://docs.info.apple.com/article.html?artnum=303173 |archive-date=2008-05-07 |access-date=2008-06-14 |website=docs.info.apple.com}}</ref> but it has been noted that some models displaying the issue have not been included. This leaves some PowerBook G4 owners with a maximum of only 1 GB of RAM to use instead of a full 2 GB.

Apple previously had a Repair Extension Program to fix the "white spot" issue on its 15" PowerBook displays.<ref>{{Cite web |title=Apple - Support - Search |url=https://www.apple.com/support/powerbook/displayprogram |url-status=live |archive-url=https://web.archive.org/web/20130123024148/http://www.apple.com/support/powerbook/displayprogram |archive-date=2013-01-23 |access-date=2016-09-01 |website=www.apple.com}}</ref>

There has also been a rash of reports concerning sudden and pervasive sleeping of 1.5 and 1.67&nbsp;GHz models known as Narcoleptic Aluminum PowerBook Syndrome.<ref>{{Cite web |date=November 14, 2007 |title=Narcoleptic PowerBook Cured |url=http://knit1spin1.wordpress.com/2007/11/14/narcoleptic-powerbook-cured |archive-url=https://web.archive.org/web/20090213143232/http://knit1spin1.wordpress.com/2007/11/14/narcoleptic-powerbook-cured |archive-date=February 13, 2009 |website=knit1, spin1}}</ref> Symptoms include the PowerBook suddenly entering sleep mode, regardless of the battery level or whether the PowerBook is plugged in. One cause is the ambient light sensing,<ref>{{Cite web |date=May 18, 2007 |title=The Cure for a Narcoleptic Laptop: Take-apart (and blog me in the morning) |url=http://www.webmonk.net/index.php/2007/05/the-cure-for-a-narcoleptic-laptop-take-apart-and-blog-me-in-the-morning |url-status=dead |archive-url=https://web.archive.org/web/20080329221739/http://www.webmonk.net/index.php/2007/05/the-cure-for-a-narcoleptic-laptop-take-apart-and-blog-me-in-the-morning |archive-date=March 29, 2008 |access-date=June 4, 2019 |website=Web Monk}}</ref> and associated instruction set coding, with possible keyboard backlight and sleep light issues accompanying the so-called "narcolepsy". Another cause is the trackpad area heat sensor; system logs report ''"Power Management received emergency overtemp signal. Going to sleep."''.{{Citation needed|date=March 2009}}

To correct this, service groups will often replace the logic board or power converter, but the actual fix (depending on the model) for the first cause is to replace or remove the left or right ambient light sensors; and for the second cause, disconnect, remove, or replace the heat sensor, or the entire top case which holds the trackpad heat sensor. Alternatively, there are reports which detail success in removing certain sensor kernel extensions or rebuilding the kernel using the Darwin Open Source project after commenting out the relevant <code>sleepSystem()</code> call; permanent resolution of the sleep issue in this manner is little documented.<ref>{{Cite web |title=.java: PowerBook narcolepsy issue hack |url=http://dotjava.blogspot.com/2006/10/powerbook-narcolepsy-issue-hack.html |url-status=live |archive-url=https://web.archive.org/web/20080906014755/http://dotjava.blogspot.com/2006/10/powerbook-narcolepsy-issue-hack.html |archive-date=2008-09-06 |access-date=2009-02-21 |website=dotjava.blogspot.com}}</ref>

The 1.67&nbsp;GHz model may suffer from manufacturing or design defects in its display. Initial reports pointed to this only being a problem with type M9689 17" PowerBooks introduced in Q2 2005, but then this problem was also seen in displays replaced by Apple Service Providers in this period (e.g. because of the bright spots issue). The devices were the last 17" models shipped with the matte 1440×900 pixel low-resolution display. After many months of usage, the displays may show permanently shining lines of various colors stretching vertically across the LCD. Often this will start with one-pixel-wide vertical lines being "stuck" in an "always-on" mode. Various sites have been set up documenting this issue.<ref>{{Cite web |title=Apple retail preps for iPhone, 17-inch PBG4 defect, EU deadline |url=http://www.appleinsider.com/articles/07/06/05/apple_retail_preps_for_iphone_17_inch_pbg4_defect_eu_deadline.html |url-status=live |archive-url=https://web.archive.org/web/20080917155258/http://www.appleinsider.com/articles/07/06/05/apple_retail_preps_for_iphone_17_inch_pbg4_defect_eu_deadline.html |archive-date=2008-09-17 |access-date=2008-08-21 |website=AppleInsider|date=5 June 2007 }}</ref><ref>{{Cite web |title=17-inch PowerBooks starting to see new vertical-line screen defects? |url=https://www.engadget.com/2007/06/02/17-inch-powerbooks-starting-to-see-new-vertical-line-screen-defe |url-status=live |archive-url=https://web.archive.org/web/20180519032647/https://www.engadget.com/2007/06/02/17-inch-powerbooks-starting-to-see-new-vertical-line-screen-defe |archive-date=2018-05-19 |access-date=2017-09-08 |website=engadget.com|date=2 June 2007 }}</ref>

On May 20, 2005, Apple recalled 12-inch iBook G4, and 12- and 15-inch PowerBook G4 batteries (model number A1061, first 5 characters HQ441 – HQ507 for the iBook, model # A1079, serial # 3X446 – 3X510 for 12" PowerBook, model # A1078, serial # 3X446 – 3X509.)<ref>{{Cite web |title=CPSC, Apple Announce Recall of iBook and PowerBook Computer Batteries |url=http://www.cpsc.gov/cpscpub/prerel/prhtml05/05179.html |url-status=dead |archive-url=https://web.archive.org/web/20120703080946/http://www.cpsc.gov/cpscpub/prerel/prhtml05/05179.html |archive-date=July 3, 2012 |access-date=July 14, 2012 |publisher=CPSC}}</ref> They were recalled due to short-circuiting which caused overheating and explosion. The batteries were made by [[LG Chemical]], in Taiwan and China. Apple has since removed the recall from its website.