Used 2008 iMac View/Fans Issues

Discussion in 'iMac' started by dlaymusic, Oct 2, 2011.

  1. dlaymusic, Oct 2, 2011
    Last edited: Oct 8, 2011

    dlaymusic macrumors newbie

    Oct 2, 2011
    Leander, TX
    So I thought I bought a good deal today for $250 at Goodwill Computer Works in Austin. A used 8,1 iMac 20", upgraded to 4 GB RAM. Before I dive into the problems, here is some background that may be of note:

    1. No optical drive - broken and removed. Optical fan constantly running (from startup) @ 5000+ RPM. With no optical drive in it, should I shut it off with a fan control program or disconnect the ODD fan?
    2. Color line down the screen (see pic in link below). "Infrared" type.
    3. Non-Apple power cord. Don't think it's meant for this machine.
    4. When I took it apart to inspect the cables and give the insides a good cleaning, I noticed a couple of things:
    • Whoever put it together did a rush job - back case was misaligned (rubber pieces at the bottom weren't properly put in place when the chassis was put back together).
    • Many of the screws were missing - here is my count so far:
    • Eight 13 mm T8 Torx (front bezel to the rear case) - there were only 4 different, obviously non-standard screws securing the bezel to the rear case)
    • Four 25 mm T8 Torx (front bezel to the rear case)
    • Two 5.3 mm T6 Torx screws securing the data display cable to the logic board
    • All the cables seemed fine.
    Gave it a general cleaning - still the line.
    When hooked to an external monitor, the line disappears.
    Noticed memory had been upgraded to 4 GB - and access door is missing : )

    With all this, where should I start? First thing I want to do is correct the graphics problem (just noticed that when it went to white screen during a restart (installing Lion) the "bar" went away). However, upon full boot it's still there.

    Could the missing screws or optical drive be causing the graphics issues? Bad cable? Bad video card? Bad screen?

    See the link below for pictures of iStat and the screen problem. Notice the graphics problem doesn't show up in the screen shot - same with a full screenshot.

    Thanks for your help, and thanks to MacRumors for being an awesome resource!
  2. dlaymusic thread starter macrumors newbie

    Oct 2, 2011
    Leander, TX

    It's been a week and no responses - no one wants to be a bearer of bad news I suppose :D ! Just to give an update on some of the issues:
    1. I bought a refurb SuperDrive from a local repair shop, paid a little more but keep my money in the community when I can. After reviewing a repair manual I found a few key components were missing: the optical drive bracket (on order), screws (more on this later), and the optical drive temp sensor and cable (on order). This explains the fan in overdrive; no temp data = default the ODD fan to light speed.
    2. As far as the band on the screen, I've heard everything from a bad screen to a bad cable. I decided to take a financial approach to troubleshooting this, so I ordered the LVDS cable and will see if that fixes the issue before moving on to the inverter and video card, last ditch being a screen replacement. Upon suggestion I created a new user account and checked the firmware; everything seems up to date and functioning fine so I don't think this is a software/firmware issue. On a side note, this computer didn't come with the original install disc (Apple Disc 3A138) and holding "D" at startup doesn't bring up the hardware test; any suggestions for running the hardware test? I do have the original discs for my Macbook (2007) as well as a Snow Leopard and self-made Lion install disc. I did update to Lion (now wish I didn't until everything was fixed - oh well...).
    3. The screws - see this post:
    4. Overall, I know I got a good deal, knew there would be some challenges/learning experiences, and I'm having a lot of fun with it, but like any other restoration project I want to do it right and get it "good as new" without breaking the bank. By the way, I don't plan on selling it; I plan on setting it up as a media center for my house (already wired for this) and as a computer for my 7 year old daughter.
    5. I would buy from the Goodwill Computer Store again (I did boot it up and checked the machine out as much as possible without taking it apart, so I knew about the optical drive and video issue), but with caution. I don't know if they are the ones who didn't bother to put it back together properly or if the person who donated it let their 14 year old take a hack at it. Plus, I was by there earlier this week and asked if they happened to have the missing screws or parts laying around in back; the employee got really defensive and kept telling me it was an "as is" purchase. Guess sometimes there is harm in asking. Still, it's a good place to buy parts and support job creation/training in the community.
  3. bizzle macrumors 6502a

    Jun 29, 2008
    The LCD issue kind of makes it not worth it. It's most likely the panel itself.
  4. dlaymusic thread starter macrumors newbie

    Oct 2, 2011
    Leander, TX
    Looks like you were right. Tested the invertor cables, swapped out the LDVS cable, checked software/firmware, and video card. None of these solved the problem. Luckily it works great connected to my external monitor; just set up craigslist alerts for scrap machines (probably going to be much cheaper to find a scrap model and pull the missing/malfunctioning parts out of it).

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