Late 2009 iMac 27" Video Card Repair — 4850 — 2nd Bake
Channel: JDW
Date: 11/07/2017

Video shows my 2nd bake of the video card. My 1st bake lasted only 4 months (due to thermal paste used, I think), and that video (showing complete motherboard removal) is here: https://youtu.be/v1DXBLkiqFM

💁🏼‍♂️ Have success? Please log your "Completion" on my iFixit Guide page at the following link by scrolling down to the "Conclusion" box and clicking on the "Give the author +30 points!" button. You'll need an iFixit account but it's free & easy. https://bit.ly/2nCnNan

⚠️ I make no guarantees the bake will work, but it does for most people as per what I read in the comments. What have you got to lose?

🤔 Think the bake is crazy? Note the NeXT motherboard was also baked (31m56s):
https://youtu.be/92NNyd3m79I?t=1916

🛠 TOOLS to open/close the iMac:
• 2 strong suction cups for front glass removal: https://amzn.to/2tkcmvJ
• Torx T10 for LCD removal (T9 works but T10 is best) & T9 for video card removal. The following kit contains more than needed for the iMac, but it's highly rated, has grippy handles and magnetic tips, and no 1 month+ wait from China: https://amzn.to/2UCaurK
-or-
Alternative kit, WRENCH style (cheaper): https://amzn.to/2wIgWWe
-or-
Alternative kit, BIT style (you'll need a handle): https://amzn.to/2vRkUeC

🔦 OTHER ITEMS needed:
• Thermal Pastes (2 types REQUIRED!)
   K4 & K5 Pro Kit: https://amzn.to/38WkEZO
   -or-
   K5 Pro (for chips other than GPU): https://amzn.to/33OIDJ6
   & Thermal Grizzly Kryonaut (for GPU only): https://amzn.to/36NMQwu

• Anti-static wrist strap (connect wire to earth ground): https://amzn.to/2uSTy74
• Dust blower - Giottos Rocket Blaster Large: https://amzn.to/2OgHHXt
• ISO Alcohol 99% (to remove old thermal paste): https://amzn.to/2YsK8v3
• Swabs & Tissues (for cleaning off the old thermal paste)
• Microfiber cloth (for cleaning the screen/glass)
• Flashlight (to peer into the dark spaces inside the iMac)
• Aluminum Foil (make feet to raise up video card in oven)
• OVEN set to 200°C/400°F (without which, this repair is in vain)
• Time & Patience

► I used a Samsung EVO 850 1TB SSD to replace the stock Apple hard drive, but the 860 EVO or Crucial MX500 are equivalent. To use an SSD in late 2009 27" iMac, you'll also need a special mounting bracket and a separate temperature sensor:
• Bracket: https://amzn.to/37Zn4qg
• Sensor: https://amzn.to/3b3knWU
• EVO 860 (1TB): https://amzn.to/2RKem9M
-or-
• Crucial MX500 (2TB): https://amzn.to/3bxHybf

🔌 IF NEEDED: Replacement Ribbon Cables:
• BIG: https://amzn.to/32Ygv7s
• SMALL: https://amzn.to/33ZEvX4

💵 NOTE: Your price on Amazon (US only) is the same even if you don't click the "amzn.to" Affiliate links above, but if you do kindly click and purchase within 24 hours, Amazon may pay me a small commission on all qualifying items in your Cart (even items not linked above).

📷 4850 Card Photos (cleaned):
TOP: https://flic.kr/p/RjLLCd
BTM: https://flic.kr/p/RjLKGf

♨️ This was the 2ns time I baked this Radeon 4850 video card at 200°C (400°F). Bake for 10 minutes. My 1st bake was lasted 4 months even with a fan-control app that set all 3 fans to 1800rpm. Symptoms: it wouldn't boot fully and would freeze at the Apple logo screen with the progress bar only 50% finished, sometimes with screen artifacts. At times when it would boot to the desktop, there were artifacts that made using the computer impossible. I think my 1st bake failed due to my bad thermal paste job. CLEAN off ALL old paste on card and heatsink, and only apply new thermal paste that I recommend above.

‼️ CAUTION WHEN REMOVING CONNECTORS! Someone attempting the bake said he accidentally ripped off a connector from the logic board. (Connector shown at 44:20 to 44:34 in video above -- one of the 1st connectors to disconnect when removing the LCD.) To avoid that, SLOWLY remove all connectors and use very little force. If something seems stuck, it could be a locking-connector where you must squeeze the tabs on the sides of the connector to unlock it and then slowly pull to remove it.

😎 Fan Control Apps to keep your iMac running cooler:
• Macs Fan Control: https://crystalidea.com/macs-fan-control
• smcFanControl: https://www.eidac.de

🎥 I'm not the only one who has gotten 2+ years of use after a video card bake. Mr. Tak Engle used my video as a guide and baked his mid-2011 iMac's video card once in Jan. 2018.  I chatted with him in Jan. 2020 and he confirmed his iMac was still working fine 2 years later.  The amazing part is he accidentally dropped it from off a bed onto a concrete floor during his disassembly, but the iMac still worked!  His bake video: https://youtu.be/3Txgc-ECNdw

🔴🔴 UPDATE: Mar. 21, 2020 — Video card stopped working after 2 years and almost 9 months. My 3rd Bake video is here: https://youtu.be/teV_atLUlpM

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#Apple #Macintosh #iMac #VideoCard #JDW