Results 1 to 4 of 4
  1. #1
    GPU issues 9,1 imac 24"

    Member Since
    Jun 03, 2014
    Posts
    2
    GPU issues 9,1 imac 24"
    I replaced the NVIDIA 130GT w/ a 4850 AMD Radeon card from a 27" imac, same year (late 2009). Computer boots, all 4 LEDs go on, computer accessible from remote screensharing on the LAN so is obviously up and running. No picture on the screen (backlighting working).

    I think it's an EFI/firmware problem w/ the new card. Any ideas as to a work-around? Edit the BIOS in the GPU to match the 24 inch screen or the Logic board ID? Thoughts? Thanks!

  2. #2
    GPU issues 9,1 imac 24"
    chscag's Avatar
    Member Since
    Jan 23, 2008
    Location
    Fort Worth, Texas
    Posts
    45,216
    Specs:
    27" iMac i5, 3.2 GHz, iPad 3, iPhone 5c, iPhone 6+, 3 iPods, Yosemite
    You can't just swap the video card in your iMac with a card from another model and especially one with a different chipset and expect it to work.

    I think it's an EFI/firmware problem w/ the new card. Any ideas as to a work-around? Edit the BIOS in the GPU to match the 24 inch screen or the Logic board ID? Thoughts? Thanks!
    That may be part of the problem but it's likely because there are no drivers (supporting kexts) for the AMD. There is no BIOS in the GPU to edit.

  3. #3
    GPU issues 9,1 imac 24"
    pigoo3's Avatar
    Member Since
    May 20, 2008
    Location
    U.S.
    Posts
    31,466
    Specs:
    2011 13" MBP 2.3ghz, 8gig ram, OS 10.7.5
    Interesting experiment...would have been realy neat if it had worked (especially since both iMacs had to have socketed gpu's).

    Firstly...to be 100% accurate:

    - the "recipient" 24" iMac is an "Early 2009" model
    - the "donor" 27" iMac is a "Late 2009" model

    So they are not the exact same model generation. The:

    - Early 2009 24" iMac is a (9,1)
    - Late 2009 27" iMac is an (11,1)

    Plus...there were no "Early 2009" 27" iMacs.

    Now interestingly (after some research)...the Early 2009 24" iMac's (via custom configuration) could have had a Radeon 4850 graphic hardware in it (just like the Late 2009 27" iMac).

    So I'm thinking (similar to chscag)...even though both computers could have had a Radeon 4850 video card installed in them...there is probably some sort of firmware difference (due to different iMac generation).

    One BIG difference between these two computers is...the 24" iMac had a core 2 duo cpu...and the 27" iMac had a quad-core i5 cpu. So these two computers certainly had different firmware.

    - Nick
    - 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

  4. #4
    GPU issues 9,1 imac 24"

    Member Since
    Jun 03, 2014
    Posts
    2
    Ah well, figured it was way too easy. I'm used to Mac's "Just Working"....I could hot-rod my old G4 and PPC pretty easily and was hoping if the GPU designation matched it would be a plug and play, didn't consider the quad core cpu.....GT 130 back in and just putting up w/ freezes when it gets too hot until I get so irritated I junk the whole thing. Not quite like hot-rodding my Roadrunner. Thanks!

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. iMac 27" A1312 EMC 2429 GPU Downgrade?
    By tekrepairsne in forum Apple Desktops
    Replies: 1
    Last Post: 07-10-2015, 02:26 PM
  2. GPU and hard drive issues
    By brkit2012 in forum Apple Notebooks
    Replies: 5
    Last Post: 01-28-2015, 10:39 PM
  3. GPU Downgrade / Interchange Info For Mid 2010 iMac 27"?
    By ENRKyle20 in forum Apple Desktops
    Replies: 21
    Last Post: 01-16-2015, 07:34 PM
  4. Mac Pro GPU Drivers/Issues
    By sputnikv in forum Apple Desktops
    Replies: 6
    Last Post: 03-28-2013, 07:07 AM
  5. GPU heat issues
    By fragbox in forum Running Windows (or anything else) on your Mac
    Replies: 10
    Last Post: 07-06-2010, 09:01 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •