G4 Cube not booting into anything

Question

G4 Cube not booting into anything

Hi All, I have received my used G4 Cube today and just installed 2 x 512MB RAM modules and Airport.

When I turned the cube on I pressed CTRL ALT P & R to reset the settings.

When the cube turns on it chimes but just stays at the grey screen with no apple icon.

Also, I inserted a retail 10.4 disk and it will not boot from this using the C key.

Also when I try and eject the disk using the eject key from booting or holding down the mouse it won't eject.

Does anyone know what may be causing all of this?

Many thanks 😟

15" Macbook Pro 2.4Ghz/4GB/10.6.4, Mac OS X (10.6.4), 11.6" Macbook Air 1.4Ghz/2GB/10.6.5

Posted on Dec 3, 2010 3:42 AM

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Answer 1

Limnos

Level 10

428,171 points

Dec 3, 2010 6:43 AM in response to Garry Westwell

used G4 Cube

I wonder if this is key. Did you try it before doing all these upgrades? Did the source say anything about non-working components? Is the PRAM battery in okay condition? If this is a total unknown then there may be a lot of preliminary testing that needs doing. On the other hand maybe you know more about it than I get in the initial message so I'll let you tell us more about it. 🙂

When I bought my QS the guy said it needed a new PRAM battery but he had just put one in. I couldn't get it to start. I had a spare PRAM battery and put it in. Started right up. Nothing's a given in used equipment.

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Answer 2

Dec 3, 2010 7:28 AM in response to Limnos

Hi it was sold as working and I saw pictures of it booted into OS9.
As soon as I got the item I added RAM and the Airport, but once I got the grey screen I took them out and just left in what the seller had installed already.
No idea if the PRAM battery is dead but would this allow the cube to boot and then just to the grey screen with no apple icon? I always thought that the PRAM would not allow the mac to boot at all but mine does and only to the great screen. Also, why will it not boot from my osx CD and why will it not eject the CD?

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Answer 3

Limnos

Level 10

428,171 points

Dec 3, 2010 7:42 AM in response to Garry Westwell

This is a wired, Apple mouse, right?

PRAM batteries can cause all kinds of strange issues. More at the boot stage but still... Can you test the battery with a multimeter?

[Texas Mac Man's PRAM, battery, PMU tutorial|https://sites.google.com/site/macpram/mac-pram-nvram-cuda-pmu-battery- tutorial]

[Apple's PRAM reset directions|http://docs.info.apple.com/article.html?artnum=2238]

If you have a digital multimeter you can check the condition of your present battery. It should read at least 3.2V if it is the 3.6V half-AA battery type. A new battery provides 3.67 Volts DC. A bad battery provides under 3.2 Volts DC. Ideally this should be measured while the battery is under load; added recommendation from Hans777:

I have recently found out that an exhausted battery will still indicate >3.6 V with a high internal resistance VM.

Checking incircuit: powercord disconnected press PMU reset button for >about 5 sec before measuring.

Checking outside: load the battery with a 1500 Ohm resistor when measuring.

Alternatively, test the battery while it is still in the computer.

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Answer 4

Dec 3, 2010 7:52 AM in response to Limnos

Hi Limnos yep wired mouse and wired keyboard.
I just took the HDD out and replaced it just incase it was not set in properly and also tried to start the cube without the PRAM battery to see if that would work and now when I press the cube power button the white light flashes once and then goes off and nothing turns on AT ALL now 😟
Could there be a problem with the PSU or the logic board maybe?

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Answer 5

Dec 3, 2010 9:01 AM in response to Garry Westwell

I have read that if the power button lights up when touched, but goes out as soon as you remove
your finger, and the computer does not turn on
During shipping the DC-to-DC board in the computer may move slightly out of its
connector. Reseat the DC-to-DC board in its connector will fix this...
Can someone explain where the Dc-to-DC board and connector is and how I reset it?

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Answer 6

Dec 3, 2010 9:43 AM in response to Garry Westwell

Hi All I have reseated the DC-to-DC board but still no power, the power light flicks on and then off with no sound or anything at all. When I look down into the cube I can still see a kind of red light on one side and a green light on the other side of the inside of the cube so I assume power is getting in....
Does anyone know what is causing this?
I don;t have anything to test the battery voltage either so all i can do is order a replacement.
Please help 😟

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Answer 7

Limnos

Level 10

428,171 points

Dec 3, 2010 9:44 AM in response to Garry Westwell

Did you try the CUDA reset as outlined in Texas Mac Man's web site?

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Answer 8

Dec 3, 2010 10:07 AM in response to Limnos

Yep just did the CUDA reset and still no joy 😟

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Answer 9

BDAqua

Level 10

250,259 points

Dec 3, 2010 10:17 AM in response to Garry Westwell

There's also a Cobe Owners site that might help...

http://www.cubeowner.com/forums/index.php?act=home

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Answer 10

Dec 3, 2010 3:00 PM in response to BDAqua

Hi thanks for that I will give the cube forum a try but I cannot post anything yet until I have been approved. Has anyone in the meantime any ideas what is causing my cube issues? If another G4 power mac was having similar issues what would the cause/remedy be?

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Answer 11

BDAqua

Level 10

250,259 points

Dec 3, 2010 3:17 PM in response to Garry Westwell

Besides the PRAM Battery that can cause really strange things, it sounds like PSU or Logic Board, bit don't know why those would go just like that, from what you did.

Does it boot to a Boot option screen if you hold the Option/alt key down at bootup?

Does it boot into Open Firmware with CMD Option+of ?

http://docs.info.apple.com/article.html?artnum=42642

reset-nvram (press Enter)
set-defaults (press Enter)
reset-all (press Enter)

Does it boot to Single User Mode, CMD+s keys at bootup, if so try...

/sbin/fsck -fy

Repeat until it shows no errors fixed.

(Space between fsck AND -fy important).

Resolve startup issues and perform disk maintenance with Disk Utility and fsck...

http://docs.info.apple.com/article.html?artnum=106214

Does it boot into Target mode...

http://support.apple.com/kb/HT1661

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Answer 12

Dec 4, 2010 2:04 AM in response to BDAqua

Hi BDAqua, the cube does not boot at all now. Infact, when I hit this morning the power button on the studio display it flicks on and then off but now when I hit the power button on the cube nothing, not even the light comes on. There is a red and a green light inside the cube core so it looks like power is getting into the cube but absolutely nothing happens when I try and turn it on. I have even tried the AC plug in different sockets in the wall incase I have a faulty wall socket.

Before all of this the cube would boot only to the grey screen with no apple logo. Tried resetting pram nvram and also resetting the CUDA and nothing. I also reseated the DC-To-DC board and nothing. The cube had a bit of a bang in transit to my house with the courier so maybe this is the cause but I can't fix it until I know what's wrong.

When the cube booted to the grey screen yesterday I put in my OSX 10.4 CD but it would not boot from that and would not eject it either. When I tried replacing the HDD and putting it back it was then that the cube stopped booting at all.....

As I said when I hit the power button today on the studio display it flicks on and then off but now when I hit the power button on the cube nothing, not even the white light comes on cube power button 😟

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Answer 13

BDAqua

Level 10

250,259 points

Dec 4, 2010 11:08 AM in response to Garry Westwell

You reseated the RAM & Video Card too?

Have you tried disconnecting the Hard Drive & Optical to see if it boots better/further?

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Answer 14

Dec 4, 2010 1:24 PM in response to BDAqua

Hey BDAqua, yep done all of that and there's just no life in it, I wonder if it's the logic board or the PSU. If it were one of those would it have the same symptoms as my cube?

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Answer 15

BDAqua

Level 10

250,259 points

Dec 4, 2010 1:40 PM in response to Garry Westwell

I wonder if it's the logic board or the PSU. If it were one of those would it have the same symptoms as my cube?

Yes, tending toward the PSU, but possibly still the Logic Board or the little start button dohickey.

You don't have one of those old KBs around with a power button on it do you?

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