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MacBook Special Report: Vertical lines appear on screen during startup
Some MacBook owners have reported an issue where a distorted screen appears during startup, characterized by a series of vertical, multi-colored lines. Usually the startup process freezes at this point, necessitating a restart.
Below is an image of the problem:
One reader writes:
"After restart the screen goes gray then random vertical lines draw on the screen.. trying to restart by pressing the start button for several seconds doesn't help... the MacBook just turns off then back to the vertical lines.. took out the power plug but that didn't help either... the only thing that got the MacBook back to normal was taking the battery out then back in. After that the MacBook restarted normally."
In some cases, users are able to temporarily work around the problem by resetting PRAM, accomplished by holding down the Command, option, P and R keys simultaneously during startup.
Bad RAM does not appear to be a factor in most cases, with users swapping out modules and still experiencing the problem.
It appears that, for many users, this problem did not appear until updating to Mac OS X 10.4.7. As such, some are choosing to revert to Mac OS X 10.4.6, per the instructions in this tutorial.
One reader writes:
"Shortly after installing 10.4.7 (initially via software update and later as the combo update), my MacBook and that of several others have developed an odd malady. Upon reboot, the screen goes completely white, then gradually more and more numerous, colored, vertical lines appear on the screen. The machine never reaches the desktop or login screen. Pressing the power button to force shutdown and restart does not clear the problem. Zapping PRAM temporarily restores normal function, but a reboot later may still result in the white screen with vertical lines.
"Some speculation is that the NVRAM has been affected by 10.4.7 and this is consistent with my experience. I initially only had a sudden shutdown problem after awakening from sleep. I had not see the white screen with vertical lines problem despite restarting the machine. That appeared after I tried resetting the PMU and zapping PRAM.
"For now I've reverted to 10.4.6 to see if my MacBook becomes stable again. Prior to installing 10.4.7, my MacBook had worked solidly for weeks without any sudden shutdowns or screen of vertical lines issues. There may be something awry with the 10.4.7 Intel update."
Another MacFixIt reader, Matthias, adds:
"I also have the 'vertical lines' problem on my Macbook. It started after I applied the 10.4.7 update and seems to appear on every restart now. Only solution I found is resetting the PRAM.
"I had originally updated using Software Update (with the re-released 10.4.7 update, I updated on July 1st). Then everything worked fine.
"Afterwards I installed the Combo updater because I wasn't sure if the Software Update version was o.k. (because the somewhat strange re-release), but this caused the "vertical lines" problem. My MacBook would only start up after a P-RAM reset.
"Now I applied the Combo updater again and everything seems to be fine again: I restarted several times, and I did not see the vertical lines again."
MacFixIt reader Chris writes:
"I too have had this problem with my white 2Ghz MacBook, ever since I updated to 10.4.7. I'm not saying that 10.4.7 is the definitive cause of this, but it never happened to me before. Every time I've shut down the MacBook and powered it up later, I have to do a PRAM reset in order for the display to come online again. Apple really dropped a bollock on this one."
Index:
- Do-it-yourself hard drive replacement instructions
- Excessive heat: Usage notes, cooling pads and more
- Final Cut Express is supported by GMA 950 chipset
- Irritating noises; eliminating
- Keyboard suddenly stops working
- Matched RAM pairs can come from different manufacturers
- Poor speaker output: Software-based workarounds
- Projector issues
- Release notes
- Sleep light oddities
- Some repaired units exhibiting wake-from-sleep issues
- Sudden shutdowns -- possible fixes
- Stains appearing at palm rests; cleaning and protecting -- Apple acknowledges
- Trackpad button "mushy", not registering clicks -- solutions
- Vertical lines appear on screen during startup
- Wireless (AirPort) dropouts -- fixes
then all was ok.
install DVD, boot into single user mode, Open Firmware, etc. without getting the
lines right away. If I reset my PRAM, I'm back to normal, but I have to do this
EVERY time I start up. I did the 10,4.7 combo upgrade.
for me.
- by ptchristy July 16, 2006 4:27 PM PDT
- When this occurs on our two Macbooks (both with 2 GHz Core Duo Intel, 2
- Like this Reply to this comment
-
(4 Comments)GBytes of SDRAM and 120 GByte hard drives all CTO from Apple) we can solve
the problem by forcing a shut down and resetting the PRAM. Once we restart
we inevitably find:
1. System Preferences... > Startup Disk is UNlocked (the padlock icon is
open).
2. No system is selected for startup.
Selecting Mac OS X, 10.4.7 and locking the padlock keeps this from
happening for a while, but eventually it recurs. When it does, we find the
same two conditions above.
One way to "keep an eye" on this is to click About This Mac and note if the
Startup Disk is selected. If not, we're at risk!