How dead is this iMac?

My G4 iMac screen just went black too about 3 days ago...I tried
zapping PRAM and nothing ..... still black. Any information would be
greatly appreciated.

Randy
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Mike Lindsay <rollme RemoveThis @anotherone.net> wrote:

 > This morning when my parent arose, the screen on their iMac - 17" 800
 > MHz G4 - was black. It's normally never shut off, just allowed to
 > sleep. Subsequent attempts at restart resulted in hang up at the grey
 > screen with no further progress.
 >
 > They called this evening (I'm 90 miles away) and I had them hold the
 > option key down at boot up to reveal any bootable volumes but none
 > appeared. My brother in law tried this a couple of times, then further
 > attempts at restart got briefly to the grey screen, then black.
 >
 > After some thought, I called back and had them try resetting pram,
 > admittedly a very long shot. I overheard a long single tone then they
 > said the screen went black.
 >
 > Is this the logic board? Hard drive? Is there a way to force the CD
 > drive tray open to get the system CD in to see if the beast will boot
 > at all?
 >
 > Thanks for the help.

What do you mean "was black." The display? No power? An elf painted
the whole thing during the night?

What did they see when they held down the option key? Did they see the
blue screen with the arrows but no volume images?

Your OP is just too vague. I realize that you are getting your info
second hand, but you have to make them answer more specific questions.

I'm a little suspicion of the power supply unit, depending on what's
they are really seeing.

--
Paul Fuchs
paulfuchs-at-attglobal-dot-net
Sitting on a small rock (St. John) in the Caribbean<!-- ~MESSAGE_AFTER~ -->
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Mike Lindsay <rollme RemoveThis @anotherone.net> wrote:

 > Is this the logic board? Hard drive? Is there a way to force the CD
 > drive tray open to get the system CD in to see if the beast will boot
 > at all?

That's impossible to say without seeing the Mac.

Have your parents buy a copy of TechTool Pro and try booting
of that CD and running the hardware analysis tools there.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: How dead is this iMac? 

In article <1ghmllg.6blf1y13na61kN%paulfuchs@porkaintkosher.oink>, Paul
Fuchs <paulfuchs.TakeThisOut@porkaintkosher.oink> wrote:


 > What do you mean "was black." The display? No power? An elf painted
 > the whole thing during the night?
a) The display was black. Apparently the machine still had power, but a
black display. When they called, my brother in law was in front of the
machine and reported that it would get to the Apple startup screen with
the spinning widget and hang there. This of course on subsequent
startup attempts. After a short period the display would go black.
They'll be gone for a couple of days so I won't be able to verify it,
but I'm at the "95% confidence level" on that.

b) I'm highly skeptical of the elf issue since their cat is a seasoned
and mighty hunter.

 > What did they see when they held down the option key? Did they see the
 > blue screen with the arrows but no volume images?
The blue screen with the arrows but no volume images.<!-- ~MESSAGE_AFTER~ -->
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stan RemoveThis @temple.edu wrote in message news:<ce8bub$k7k$5@cronkite.temple.edu>...
 > Mike Lindsay <rollme RemoveThis @anotherone.net> wrote:
 >
  > > Is this the logic board? Hard drive? Is there a way to force the CD
  > > drive tray open to get the system CD in to see if the beast will boot
  > > at all?
 >
 > That's impossible to say without seeing the Mac.
 >
 > Have your parents buy a copy of TechTool Pro and try booting
 > of that CD and running the hardware analysis tools there.

Actually, have them try booting from the OS X installation disc before
shelling out for techtool pro. If it won't boot at all, there's no
point getting TTP, at least not for resolving this issue.

'cid 'ooh<!-- ~MESSAGE_AFTER~ -->
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btree error <rollme.RemoveThis@anotherone.net> wrote in message news:<280720041240270561%rollme@anotherone.net>...
 > In article <1ghmllg.6blf1y13na61kN%paulfuchs@porkaintkosher.oink>, Paul
 > Fuchs <paulfuchs.RemoveThis@porkaintkosher.oink> wrote:
 >
 >
  > > What do you mean "was black." The display? No power? An elf painted
  > > the whole thing during the night?
 > a) The display was black. Apparently the machine still had power, but a
 > black display. When they called, my brother in law was in front of the
 > machine and reported that it would get to the Apple startup screen with
 > the spinning widget and hang there. This of course on subsequent
 > startup attempts. After a short period the display would go black.
 > They'll be gone for a couple of days so I won't be able to verify it,
 > but I'm at the "95% confidence level" on that.
 >
 > b) I'm highly skeptical of the elf issue since their cat is a seasoned
 > and mighty hunter.
 >
  > > What did they see when they held down the option key? Did they see the
  > > blue screen with the arrows but no volume images?
 > The blue screen with the arrows but no volume images.

In that case, either OpenFirmware is screwed up (which could be due to
factors) or some hardware between the discs and the processor is
screwed up.

Although an OpenFirmware issue is preferable to a hardware issue,
mucking about with it is well beyond the scope of this post. What I
suggest is that you try to rule out a few possible hardware failures
before dealing with OF. First, do your parents hear the hard disk
spin up? If not, a loose internal power cable could be to blame. If
the disk does spin up, it is possible that the internal IDE cable has
become detached from the drive or logic board. Outside of that and
(possibly) OF, I don't think there are any relevant user serviceable
parts.

'cid 'ooh<!-- ~MESSAGE_AFTER~ -->
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 >This morning when my parent arose, the screen on their iMac - 17" 800
 >MHz G4 - was black. It's normally never shut off, just allowed to
 >sleep. Subsequent attempts at restart resulted in hang up at the grey
 >screen with no further progress.

This can indicate one of a number of problems. Working from most likely to
least likely:

1. The operating system is damaged or corrupt, likely due to a hard disk
directory error. A program like DiskWarrior can fix this.

2. A device connected to the system is malfunctioning or defective. i have seen
this "gray screen" hang on modern Macs caused by a defective mouse, and also by
a defective external USB CD recorder. Have them disconnect EVERYTHING--mouse,
keyboard, and all--and try turning the machine on.

3. A defective or failed hard drive. If the computer can boot from a CD, but
running Disk Utility shows no hard drives connected to the system the hard
drive has failed. Some hard drive failures can also prevent booting from a
CD-ROM on the same IDE chain; the hard drive's ribbon cable must be
disconnected to test this.

4. Bad RAM. This will cause the gray-screen hang in some circumstances, often
accompanied by a long tone on bootup.

5. A bad power supply. Often indicated by a sysem that powers up and then
either powers down right away, or makes a "clicking" sound followed by a power
down.

6. A bad logic board.

 >They called this evening (I'm 90 miles away) and I had them hold the
 >option key down at boot up to reveal any bootable volumes but none
 >appeared.

If the pen Firmware boot device selection screen appears, this rules out many
forms of logic board failure. If a bootable CD is inserted, does it appear?

 >After some thought, I called back and had them try resetting pram,
 >admittedly a very long shot. I overheard a long single tone then they
 >said the screen went black.

This long tone is worrisome. It indicates a hardware failure--usually bad RAM.

 >Is there a way to force the CD
 >drive tray open to get the system CD in to see if the beast will boot
 >at all?

Hold down the mouse button at powerup, and continue to hold it down until the
CD tray pops open; this will work if the computer is healthy enough to at least
initialize Open Firmware.

--
Art, literature, shareware, polyamory, kink, and more:
<a style='text-decoration: underline;' href="http://www.xeromag.com/franklin.html" target="_blank">http://www.xeromag.com/franklin.html</a><!-- ~MESSAGE_AFTER~ -->
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Mike Lindsay <rollme.TakeThisOut@anotherone.net> wrote:

 > This morning when my parent arose, the screen on their iMac - 17" 800
 > MHz G4 - was black. It's normally never shut off, just allowed to
 > sleep. Subsequent attempts at restart resulted in hang up at the grey
 > screen with no further progress.

I don't know if this applies to flat screen iMacs but those are the
symptoms of a dead PRAM battery ... on most models a cheap and simple
replacement.

--
Adrian<!-- ~MESSAGE_AFTER~ -->
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In article <1ghlprh.cij3051dn8zswN%matt@tidbits.com>,
matt.RemoveThis@tidbits.com (matt neuburg) wrote:

 > Mike Lindsay <rollme.RemoveThis@anotherone.net> wrote:
 >
  > > This morning when my parent arose, the screen on their iMac - 17" 800
  > > MHz G4 - was black. It's normally never shut off, just allowed to
  > > sleep. Subsequent attempts at restart resulted in hang up at the grey
  > > screen with no further progress.
  > >

 >
 > Do these puppies have a PRAM battery? If so I'd make that my first
 > suspect. m.

I believe so - at least my daughters 17" 1G G4 has one. However, you
have to remove the bottom housing to get to it. There are a lot of
warnings about replacing the thermal paste and torqueing the screws to
the proper torque in order to preserve the proper heat transfer whenever
the bottom housing is opened.


However, if the battery setup in the 17" 800MHz is the same as my
daughters 1GHz, you don't need to open the bottom housing to test the
battery. There is a battery voltage test point under the user access
door where the battery should measure at least +3.5 volts.

To the OP's first question:

I would first try to boot while holding the mouse button down to attempt
to open the CD tray, and if successful, to attempt to boot off the Apple
Diagnostic CD (while holding the 'C' key down) that came with the iMac,
and then run the tests.

--
-Ernie-

"There are only two kinds of computer users -- those who have
suffered a catastrophic hard drive failure, and those who will."

Have you done your backup today?<!-- ~MESSAGE_AFTER~ -->
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The post from "btree error" was me under another iD.

I'm going over there this weekend to check the situation firsthand
since they won't be home until then. I found a copy of the service
manual online and I'll take some tools and a volt meter to do some
troubleshooting.

Many many thanks to all who have replied. I've gotten much good info
from you all.

I'll update on the outcome. And keep an eye out for elves carrying
buckets of black paint.

Mike L
mlindsay4 at cox dot net
 >> Stay informed about: How dead is this iMac? 

I had a very similar situation with my wife's iMac. The symptoms -- it
was dead as a door nail -- seemed to have all the markings of a
hardware problem. I checked the pram battery, which was fine, as they
almost always are, and tried swapping memory, all to no avail. The CD
tray would not open, so (on someone's advice here or on the Apple
forums), I booted the iMac up in Firewire target mode and confirmed
that I could access its hard drive with my laptop. So I knew the drive
was probably o.k. Next I discovered that I could boot the iMac from a
remote Firewire drive. That seemed to rule out the logic board and
just about everything else.

Finally I copied the home directory, then using the laptop's CD drive I
did a remote clean reinstallation of the operating system. The machine
has been fine ever since.

--
George Johnson
johnson AT santafe DOT edu
http://talaya.net
 >> Stay informed about: How dead is this iMac? 

 > (a black screen) This can indicate one of a number of problems. Working from
most likely to
 > least likely:

1....6...

You missed one or two, which was always the first to check with my parents.

7. Monitor is not turned on

8. Monitor is unplugged

9. Powerstrip is turned off or breaker in strip is blown.

But the OP already ruled those out...<!-- ~MESSAGE_AFTER~ -->
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