# Replacing emi foil on iMac?



## fifthmanstandin (Oct 17, 2008)

so here's a sort of storyline

I became the proud owner of a 2006 intel iMac back about a year ago. The computer was second hand and generally came with nothing other than a keyboard and mouse. Nothing else. I was in love for about 8 months until my internal hd crashed and needed replacing. With no apple stores near me and no paperwork that came with the system I figured I'd install it myself. I had done a lot of computer work before that point so I didn't have any problem navigating the system hardware. What did throw me however was running into the emi foil, at the time I had no idea what it did beyond discourage tampering so I took a razor blade to it and after a few clean cuts, went on with my tampering. New hd installed fine and I've been happy with it ever since. Except for the overheating issue. 

Prior to foil removal I had no noticable problem with overheating but about 6 months ago I noticed drastic performance issues with my GPU : freeze ups, graphical tearing, the gamut. I installed iSlayer's temperature widget and found that right about the time it crapped out was 58-60 degrees Celsius, and that it only got that hot when I played warcraft. I turned the settings down on warcraft and installed SMCfan control and turned the fans up. This held it together up to now. In the winter months when my house's heat is on and the ambient temperature is around 80, it's starting to get worse. Short of playing in the cold I'm wondering if this can be remedied with a foil replacement. I scoured everywhere online and couldn't find anything other than emi tape. 

Since I have access to a boundless supply of copper (Recently finished my BFA in Metalsmithing & Jewelry) and copper foil, I'm wondering if I can order28-30 gauge copper foil and tack that back down to the system much like the original emi foil was. To me, this would make sense as a fix being that the emi foil created a sort of controlled space for airflow, whereas now the whole front of my comp is open to air from elsewhere. Copper also acts as a good heatsink. 

any ideas?


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## sinclair_tm (Mar 11, 2005)

I really doubt that the foil has anything to do with the over heating. It could be that the GPU is bad, or the heatsink on the GPU has come loose or moved while you were in it. So of the heatsinks are held on by springs and plastic clips. I did have one on a video card in my PC come off by it self after 2 years. Here is a link to some take apart info, and links to pictures. Look ad see if you removed anything more then they said too. Basically, if you moved the heatsink on the GPU, you have to clean it and apply new thermo grease or it will over heat. Also make sure that all the fans are still spinning and are not blocked.


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## fifthmanstandin (Oct 17, 2008)

Well like I said, when I was in there last time I opened up the gpu's heatsink and redid the heatsink paste, paste was fine as far as thin/thickness of it. I'm really thinking it's the lack of 'airtighness' of it all.


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## sinclair_tm (Mar 11, 2005)

Then I'd try aluminum foil. It's basically the same as the EMI foil, and cheap as you can get it at the local store


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## fifthmanstandin (Oct 17, 2008)

worked like an f'ing dream. Lowered my gpu temp by about 20 degrees Celsius


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## sinclair_tm (Mar 11, 2005)

Well, that surprised me. Learned something new. I wonder if Apple designed it as a cheap heatsink extender, or as air flow controler.


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