iMac 27" mid 2010 AMD Radeon 5750 (5850m) flash error

Discussion in 'iMac' started by iMacOwnerDK2013, Mar 17, 2013.

  1. iMacOwnerDK2013 macrumors newbie

    Mar 17, 2013
    Dear friends,

    I am a very sad man right now. I did something very stupid and even-though my gut instinct was telling me otherwise I decided to do so. I wasn't aware of that changing the ID tag would have these consequences, but it did say caution. I took a backup of the BIOS, but it is on my iMac, which is not working now. The screen is black and I used my original bios with some tweeks. I was stupid enough to choose an option in ATIFlash, where I selected it to be recognized as a Radeon HD 6870. Now the screen is black and I cannot do anything. The computer starts and everything, but I cant see anything.

    I was thinking about making an automated flash CD that flashed it back. Would that work? Does anyone have the original BIOS file for the card? Mine is on the iMac harddisk... I feel so stupid right now

    A friendly member here just informed me that the Video ID in RBE should not be the problem. Could the problem be that the clock was set to high? The default was 625 and I sat it to 675 or 700?

    I have just tried to reset the NVRAM and PRAM but no difference?

    The same person also told me that the video id option in RBE should not have caused the problem? The machine is booting into OSX as normal with sounds and everything... But there is no picture at all. Everything is black, but there are no error sounds either?

    I just had an idea!!! Could it be an power issue? I mean that the GPU is not getting enough power or voltage perhaps?

    I just remembered something today! My GPU has GDDR5 RAM! ATIFlash said something about it not being able to read it correctly! Did this be the cause of problem maybe??

    And is there an ATIFlash specialist in here? Any expert with the different commands and such? I've been looking through the command list and maybe.... just maybe, I can still save it!


    I honestly do believe that this is not a lost cause! There are none of the errors sounds that you hear if the MOBO is dead or so. Or if there is a GFX error (in the PC/Windows world). So I am convinced that it can be done. I do not think that I need to buy a new MOBO... Because then I could just as well buy a new iMac.

    As I see it there are two options, but I hope option one can be done:

    1) Blind flashing - Boot from CD, flash from USB and discover the error log. I saw there was a -scansii attribute. Is there a way so that I can flash it where ATIFlash discard everything and just flash the damn thing as I state? I do think that it can find a device id, but I cannot confirm it. Is there a way to perhaps change the device id or clock speed, voltage and such without accessing the BIOS of the VGA card? Because the problem could be that the VGA card is not getting enough power - because I tweaked it.

    2) Manually removing the BIOS reflashing it and inserting it. But how do I find the VGA BIOS? Can could I just buy an empty one from a electronic shop, flash it and insert that one and clipping the old one out? :(
  2. jahelin macrumors newbie

    Oct 18, 2014
    black screen

    Did you ever find out a solution to your problem. My iMac2009s graphic card died and I got an used 6870m from an alienware laptop since original imac parts are hard to find from Europe and anyways the prices are ridiculous in ebay. I am trying to find if I am supposed to flash the card to make it work.

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