[Archmikus]

Hi all. I'm happy to announce that my new flat-panel iMac should be arriving next week and I already bought a 120 gig hard drive to replace the little 60 gig it ships with (what can I say, I need my space!). I have the draft version of the service source manual that's been floating around the net and it looks like I can manage the hard drive replacement pretty well on my own. My only question is: where can I get my hands on these thermal pads? I understand I can find the thermal past at Radio Shack or Best Buy, right? What brand/name should I look for? Thanks in advance!

I'd look in a cheapo discount PC store, one where they service PCs as well as sell them.

Radio Shack will probably have it, but you'll pay more.

[TNproud2b]

It's only $2.00 for what amounts to a lifetime supply in a little tube.

Get it at Radio Shack...don't see how you could possibly pay too much.

[JoeG4]

I have a huge tube (just like a small cualk tube) that I bought from a company that makes this stuff in real bulk.. best part is the heat conductivity is about as good as artic silver!

The real trick is going to be those pads, what I'd do is do the best you can preserving what's there, replace it with really high conductiviity 'PRO' version stuff, make sure it's the right thickness, and get it just right.. you'll be in great shape.

Artic silver II is the perfect solution for the other heatsinks *sigh* Why did apple have to make even upgrading the ram such a bitch?

IMO I'd buy mine all tricked out just to avoid that btich

[Dan Szwarc]

My understanding is the pads are crap. Compared to thermal paste, they are not nearly as effective as transferring the heat. It should be OK to use thermal paste in place of thermal pads. The pads are great for manufacturing because they are easy to apply and not as messy.

The only concern is if the pad helps take up some gap as thermal paste is preferred only for very close thermal junctions. Too much paste makes for less thermal conductivity. If you can close any gap, then no problem.

[kstevens]

You DON'T need the thermal pads to replace the HD. The thermal pads are only necessary if you remove the mother board from the bottom housing. The only time you need to do this is if you have to replace the mother board.


Ken

[Archmikus]

Ken I looked at the manual again and I think you're right: it appears you only need to replace the thermal pads if you remove the logic board from the bottom housing (which I won't be doing). To replace the hard drive all I'll need is the thermal paste, and if you ask me this looks pretty easy!

Thank you everyone for your help!

[Bubba]

if you talk real nice to an apple service person in your area, and maybe give him a few bucks, they might be able to get you some.. since they need to be able to get them themeselves for repairs...

[MoontaMacman]

Just to add a touch of drama and paranoia to your daily diet- a PC technician friend of mine tells me that Thermal Paste is highly carcinogenic - which made me wonder about Apple recommending the use of a fingernail to remove old paste if a spatula of suitable type is not available- I gather the quantities are minute but if one is as cack-handed as I am one could well end up wallowing in the stuff - just a cat tossed in among the pigeons to keep you alert

Ron

[TNproud2b]

If thermal paste was harmful, I would be dead.

In the case of the new iMac, the thermal grease improves the heat conductivity between the mating surfaces of the chassis - which also acts as the CPU heatsink and EMI shield. The CPU is not directly fitted with a heatsink, instead it uses a heatpipe to 'move' the heat to a remote heatsink (the chassis). A loose or otherwise inefficient bond between the heatpipe and heatsink (the gap where the thermal paste is needed) would result in the loss of ability to cool the CPU. It would fry, probably within a couple of minutes.

Heatpipes are interesting technology. Almost magic, in my opinion. They have been used for decades to cool semiconductors, mostly in laptop computers and servers. It's a super-efficient way to transfer heat from point A to point B - almost lossless. The heat needs a place to be dissipated (point B, the chassis) and an uninterrupted path on its way there (mind the gap), too.

Brief explanation of heatpipe principle: http://home.t-online.de/home/Gerhard...uer/wirk-e.htm



[ 01-19-2002: Message edited by: TNproud2b ]

[Dan Szwarc]

...so that black heat sink must be the GeForce2MX chip.

It's funny when the video need a bigger heat sink than the processor.

But not really funny.

[kstevens]

What do you mean, the heat sink for the processor is the entire chassis.


Ken

[Hemingray]

Homer: Mmmmmm... thermal paaaaste....