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Thread: imac 400 dv HELP!!

  1. #1
    Join Date
    Dec 2003
    Posts
    18

    Default imac 400 dv HELP!!

    have problem with imac 400 dv monitor will not work at all, can not use external monitor via vga hook up either. Just black screen, actually when plugging in ext. monitor which is definately a working monitor, when i boot imac monitor flashes bright white and then the monitor power led goes off and only a black screen remains. Almost as if it is powering down the monitor...and the imac itself boots, get tone, powerbutton illuminates green but no monitor activity at all, can hear the drive spinning just like normal all seems great excpt monitor. does this sound like a fbt problem or crt. Also last tidbit, this is a friends imac, and the last thing she did was upgrade the system on HD I'm not sure which system she up'd to or from, but i have heard of problems with syst upgrades on imacs without firmware upgrade...any further info on this situation would be helpful...also if firmware could be problem how does one go about accessing the HD when one can not see monitor to even set up HD for sharing or use over network, is pulling HD and installing elseware the only way...>? And if so how to access HD once back in imac. And , LOTS OF ANDS HERE HUH!< which firmware is needing upgraded in previously mentioned situation , can it be done without monitor ???ETC ETC>>

    Thanks for any and all wisdom on this matter I am not so familiar with this Imac thingy mostly legacy and G4 desktop experience here!

  2. #2
    Join Date
    Feb 2001
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    on the landline, Mr. Smith
    Posts
    7,787

    Default

    This is a serious issue that is all too common in imacs of this vintage. Nothing handy right now, but I will post more info when I can; I think I have a link to a success story somewhere....

    You can search for "imac + video" or something similar here at the Gurus (and google too) and you will see others have suffered the same fate, and rarely recover from it.
    "Imagine if every Thursday your shoes exploded if you tied them the usual way. This happens to us all the time with computers, and nobody thinks of complaining." -- Jef Raskin

  3. #3
    Join Date
    Aug 2001
    Location
    Grangeville, ID USA
    Posts
    9,119

    Default

    I just put a copy of the iMacDV Service Manual on my iDisk for you. In it is instructions for resetting the PMU. You'll need to pull the iMac down to get to the motherboard. Follow the directions precisely and only press the PMU the one time. Service Manual

    Along with the PMU reset are numerous other things to try. You might even try an Open Firmware reset and see if the monitor gets turned on there. OF is independent of Operating System installs and should be available if the issue is a florfed update to a newer OS.

    Hold the Command+Option+O+F keys during restart. You should get a '>' prompt. At that prompt type:

    >reset-nvram
    Return
    >set-defaults
    Return
    >reset-all
    Return

    The computer should restart. You might even try that without being able to see the text on the monitor, hoping the computer booted in OF.

    Keep at it. Hard to hurt it worse now.

    RIck
    molṑn labe'
    "I am a mortal enemy to arbitrary government and unlimited power. I am naturally very jealous for the rights and liberties of my country, and the least encroachment of those invaluable privileges is apt to make my blood boil."
--Ben Franklin

  4. #4
    Join Date
    Dec 2003
    Posts
    18

    Default

    tried the OF reset, blind, no monitor and no response...I tried to connect to service manual link and it said file damaged can not load after opening acrobat reader within a ms explorer window and downloading the 9 meg file...should this link have worked using reader plugin or would i need to turn plugin off to simply download and then open reader seperately to open file>??

  5. #5
    Join Date
    Feb 2001
    Location
    on the landline, Mr. Smith
    Posts
    7,787

    Lightbulb

    OK, here we go...

    Here is a link to, well, a link that is a long document (actually 3 differenet links/formats of the same document) that covers the problem(s) and potential fixes.

    I have not done this myself yet, but am familiar with the problem and it looks like the author has all his ducks in a row.

    Before you dive in, it would be wise to decide what the imac is worth to the owner, and how the work will be done. There is a good chance that the repair is more trouble/cost than the imac is worth if it is taken to a shop. If you decide to scrap it, don't drop it in a garbage can; the parts are worth as much as the whole thing!

    a snip of the decsription of the problems:

    The symptoms seem to vary slightly between the different iMac models but the following are often reported.

    S1. iMac starts up but with blank display. You should hear the chime, the HD spin up, and the chatter of the HD as the OS loads. Youwill probably not hear the ?thump” of the CRT coils loading up nor the crackle of static which can sometimes be heard as the high tension voltage builds up in the CRT. If your iMac didn?t perform a proper shutdown the last time, in order to complete a successful bootup you may need to press the <Return> key to a clear a dialog telling you the hard disk is going to be checked, and again when the check is complete.

    S2. iMac starts up normally but with dim or strangely coloured display. The full iMac fruit flavour spectrum has been reported.

    S3. iMac does not respond following a warm reboot/reset or if the power is turned on after a shutdown without pulling and replacingthe power cord first. After the reset/reboot/power on the LED shows green but nothing else happens and the screen is blank.There is usually no startup chime. You may hear a very faint clicking (from the hard drive?).

    S4. iMac turns itself off 7 ? 10 seconds after power-on, even if the power cord was pulled and replaced. You will probably hear the hard drive spin up briefly, and the screen (or external monitor) may come on momentarily. You will probably not hear the?thump” of the CRT coils loading up/relays switching nor the crackle of static which can sometimes be heard as the high tension voltage builds up in the CRT.

    The symptoms may vary and be experienced in combination.
    Yell if you have questions. I will be reviewing this doc myself, but am short on time right now....
    "Imagine if every Thursday your shoes exploded if you tied them the usual way. This happens to us all the time with computers, and nobody thinks of complaining." -- Jef Raskin

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