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  1. #1


    Member Since
    Dec 25, 2012
    Location
    Malta
    Posts
    12
    Specs:
    G4 Quicksilver 733Mhz 256mb ram, 40gb hdd, also G4 Imac 17inch flat panel 800Mhz, 1gb ram, 80gb hdd
    G4 Quicksilver 733Mhz dead
    Hi, I have a G4 quicksilver which when I press the power button lights up the white led but nothing happens. No fans turn, no red led inside. Have tried replacing the internal battery but still the same. Can anybody help please?

  2. #2

    pigoo3's Avatar
    Member Since
    May 20, 2008
    Location
    U.S.
    Posts
    34,860
    Specs:
    2011 13" MBP 2.3ghz, 8gig ram, OS 10.8.5
    Thread moved to more appropriate location. "Community Suggestions & Feedback" is not the correct location for a desktop computer question.

    Thanks,

    - Nick

    p.s. Regarding your question...it could be a dead power supply.
    - Too many "beachballs", read this: Beachballs
    - Computer seems slower than it used to? Read this for some slow computer tips: Speedup
    - Almost full hard drive? Some solutions. Out of Space
    - Apple Battery Info. Battery

  3. #3


    Member Since
    Dec 25, 2012
    Location
    Malta
    Posts
    12
    Specs:
    G4 Quicksilver 733Mhz 256mb ram, 40gb hdd, also G4 Imac 17inch flat panel 800Mhz, 1gb ram, 80gb hdd
    re power supply check
    I checked the power supply voltages by bypassing the power standby(green wire in psu) and all the voltages are present. Also when that is done on the logic main board, the red led then lights but nothing. Also checked some voltages on the cpu transistors and supply is going there,and fans switch on, only when I bypass the green wire on the power supply to ground, but still no chime like it is dead.

    All I wish to know is whether to order a CPU or logic main board since I do not have any parts I can try with and do not want to buy the two of them.

    Thanks and any help would be appreciated.

  4. #4

    baggss's Avatar
    Member Since
    Oct 10, 2004
    Location
    Margaritaville
    Posts
    10,311
    Specs:
    27" 3.4 Ghz i7 iMac-13" C2D Macbook-OSX 10.10.2 -64Gb iPad 2-64 Gb iPhone 6+-ATV 2-14Tb of Storage
    Faulty RAM maybe?


  5. #5


    Member Since
    Apr 24, 2009
    Location
    UK
    Posts
    744
    Specs:
    MacBook Pro 15" 2.8 GHz
    Based upon you powering on the PSU by shorting the green wire to ground proving it is good, another option is power switch/PCB failure. Some used to fail regularly, a white plastic label on an IC used to shrivel up from heat on some PM G4's, can't remember if it was the QS or earlier models. Disconnect the power switch, then use the on switch on an older USB keyboard and see if it powers on.

    If not the logic board failed is a strong possibility.
    Steve
    UK

  6. #6


    Member Since
    Dec 25, 2012
    Location
    Malta
    Posts
    12
    Specs:
    G4 Quicksilver 733Mhz 256mb ram, 40gb hdd, also G4 Imac 17inch flat panel 800Mhz, 1gb ram, 80gb hdd
    About the ram, no the ram stick is surely good because I removed it from another Imac G4 (Ishade) and it works perfectly plus it would beep I presume.

    Regarding the power switch pcb, yes there is a possibility that it is faulty, but there again When I short that green contact on the power supply, should'nt I be able to hear the tone. Unfortunately I do not have an old usb keyboard with the power button.

    As I said, when I short the green wire in the power supply I can get voltages on the cpu.

    Is there a way to check if it is the front panel pcb by maybe eliminating it temporarily?
    I will remove the front pcb and check to see if there are any signs unless there is somebody who can guide me into checking some voltages on that board.

    The wierd thing is the red led on the logic board lights when I jump that green wire.

  7. #7


    Member Since
    Dec 25, 2012
    Location
    Malta
    Posts
    12
    Specs:
    G4 Quicksilver 733Mhz 256mb ram, 40gb hdd, also G4 Imac 17inch flat panel 800Mhz, 1gb ram, 80gb hdd
    Update

    Removed small panel board, no sticker found on it caked but it could be faulty.
    Measured all voltages. They are all slightly higher than supposed to be like the 3.3v being 3.5v, 12v being 12.6v, -12v being -12.4v, 5v being 5.2v,
    except the 28v being low at 25.8v.

    Also first the fan in front of the cpu starts at full speed and then slows down. No display on monitor, no startup tone, nothing but the red led on and the fans.

    I'm starting to think it might be the logic main board. do not know if I can test any further. If there is please let me know.

    Many thanks

  8. #8


    Member Since
    Apr 24, 2009
    Location
    UK
    Posts
    744
    Specs:
    MacBook Pro 15" 2.8 GHz
    Quote Originally Posted by freccia View Post
    Regarding the power switch pcb, yes there is a possibility that it is faulty, but there again When I short that green contact on the power supply, should'nt I be able to hear the tone. Unfortunately I do not have an old usb keyboard with the power button.
    You are right, I missed that.

    As you say, it is looking like a logic board issue.
    Steve
    UK

  9. #9


    Member Since
    Dec 25, 2012
    Location
    Malta
    Posts
    12
    Specs:
    G4 Quicksilver 733Mhz 256mb ram, 40gb hdd, also G4 Imac 17inch flat panel 800Mhz, 1gb ram, 80gb hdd
    Thanks techiesteve for your support. I appreciate your help. Will try to order one from ebay hopefully, it's either the logic main board or the cpu anyway but more likely to be the board.

    Happy New Year and will see how it goes eventally.

  10. #10

    harryb2448's Avatar
    Member Since
    Nov 28, 2007
    Location
    Nambucca Heads Australia
    Posts
    22,018
    Specs:
    Imac 27" Retina 5K, 512GB Flash Storage, 3.3Ghz, 16GB memory, OS X.11.5.
    Don't overlook replacing the PRAM battery before lashing out on more expensive hardware.
    Hang on to those original install discs like grim death! Using OS X.7 or later make a bootable USB thumb drive before running Installer!

  11. #11


    Member Since
    Dec 25, 2012
    Location
    Malta
    Posts
    12
    Specs:
    G4 Quicksilver 733Mhz 256mb ram, 40gb hdd, also G4 Imac 17inch flat panel 800Mhz, 1gb ram, 80gb hdd
    Replaced the PRAM battery, but all for nothing. Maybe I am not resetting the PRAM properly. Let me explain what I did maybe I am doing something wrong.
    Waited overnight without battery.
    Pressed the pram switch 15 seconds without battery and power continuously.
    Placed the battery back on the board.
    Measured the battery voltage which was 3.27volts
    Put the power cord back on.
    Pressed the power button. The light on it illuminates for the amount I press the button then it fades off.
    No red led no fans nothing.

    Hope I am not doing anything wrong. If I am doing anything wrong or I have skipped a step or something, please do correct me before I go out for a main board.

    Thanks guys.

  12. #12

    Mac SK's Avatar
    Member Since
    Oct 20, 2006
    Posts
    1,513
    Pull out the video card and reseat it. Unplug the hard drive and try to start it up.

  13. #13

    Air's Avatar
    Member Since
    Feb 22, 2012
    Location
    West Virgina
    Posts
    109
    Specs:
    See Signature
    Reseat ram, reseat IDE cables, Blow it out with an air compresser or a leaf blower, check for loose cables, then test. Make sure you check the caps also
    [Main Laptop/Computer] [April 2006] 17" MacBook Pro | 2.33GHz C2D | 4GB DDR2 RAM | 120GB Intel 320 SSD | Lion 10.7.5

  14. #14


    Member Since
    Dec 25, 2012
    Location
    Malta
    Posts
    12
    Specs:
    G4 Quicksilver 733Mhz 256mb ram, 40gb hdd, also G4 Imac 17inch flat panel 800Mhz, 1gb ram, 80gb hdd
    Will it beep or do something without the video card? Because maybe my video card is faulty. I need to try that one out.
    I have reseated the ram many times, removed IDE connector of cd and hard disk, tried without ram as well.
    I have removed the motherboard from its place to check for any signs of burnt components but nothing, no components seem to be burnt at least visually and no overheating of any component.
    About the capacitors, I have looked at them, there are no real signs of leaking capacitors, but i can see like a hairline on some of the metal capacitors especially close to the cpu board. None are shorted but you cannot know if they leaky unless you replace a couple, which I might consider.
    I have repaired other pc motherboards before but you could visually see the capacitors bulging (inflated). They seem to use good quality capacitors on these motherboards though.
    Maybe someone can enlighten me if it is worth replacing the capacitors if you think it could be from those, I might have a go at them.
    Thanks guys for your support and help, really appreciate it.

  15. #15

    Mac SK's Avatar
    Member Since
    Oct 20, 2006
    Posts
    1,513
    A bad video card will keep this model from starting up. Reseat the video card. Keep one stick of memory and disconnect the HD...then crank it up. Theres led's on the board that should lite up next to the CPU.

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