Heatsink paste und Cinema Display hackage

[FdB]

A little dab’ll do ya. Or... "I Was A Heatsink Paste Virgin".

Given that all G4’s are at least 14 years old now (just barely past puberty), I wondered what sort of condition the heatsink paste between the CPU’s and the heatsink might be in. My MDD Dual 1.42 GHz operating temperature brought this concern to mind… always running stable at 137º F after a mere 1 hour run time, while my 1.25GHz Dual MDD runs much-much cooler.

I removed the copper heatsink to investigate, after I procured a very small tube of Arctic Silver 5 heatsink paste. Evidently the previous owner of this MDD thought that if a little paste was good… a lot of paste would be even better! Anyway, it took me about 10 minutes to get all of the old paste off of the CPUs and heatsink using 91% isopropyl alcohol and some Q-tips. Then using 0000 steel wool, I removed tarnish from the copper heatsink where it was to near-contact the CPUs. (Do not try this at home!) Knowing full-well that tiny portions of the steel wool might remain or somehow be introduced into the space between the CPU and heatsink. (Anyway, I did this in the garage far away from the computer and then blew the heatsink with compressed air before getting anywhere near the CPUs.) I again cleaned the heatsink surface with the alcohol to remove any grease or residual slime before applying any new paste.

Then, I carefully broke a single-edged razor blade in-half (using vice-grips), to use as a trowel or “spreader” for the paste. I’d removed all RAM and cards from the machine to allow the most access for my oft-clumsy big ol’ hand. (Touched metal razor blade to metal frame of machine for grounding/static release before proceeding.) On the processor closest to the hinge I applied a bead of paste about half the size of a BB and spread it over and around the processor in a very thin (seemingly even), “skim coat” with the half razor blade. Then, did the same to the second processor of this dual processor board. And then, did the same to the two areas on the heatsink where it would meet the individual processors. Of course, I moved the heatsink slightly to the left and right a few times after contact, in a restricted circular fashion while applying downward pressure, before putting the screws in place and torquing them down.

Replaced RAM and video card and fired it up. Opened temp sensor app and watched as the temp took off like a rocket in the first ten minutes before slowing (all-the-while thinking that something was indeed amiss and that I was hell bound to cooking my CPU's). It reached 120º after thirty minutes and then it stabilized at 131º after 45 minutes. 2 hours later, still at 131º.

So, reduced operating temperature by 6º overall, simply by applying fresh paste. *Maybe a little tray for dry ice placed under the front air intake would bring temps down even more? Anyone else remember the window mount coolers for your car, or the canvas covered water bags for desert crossing? (I am kidding, will not attempt dry ice method.)

Apple Cinema Display

Then I fired up the trusty 1.25 GHz Dual MDD and the Cinema Display monitor did not work! Switched it with another identical Cinema Display that immediately worked using the same power puck. (First display only showed the short-long-short blinks from the displays’ power indicator.) Examined the power cable (into the puck), and found traces of scotch tape, which I immediately removed from the exterior of the plug. Quick web research provided the scotch tape hack/fix which explained that covering the middle two contacts inside the plug with scotch tape would remedy this non-working Display state. Voila! Display working again.

So, I didn’t fall prey to Nano’s “Total Eclipse Pseudo Virus” after all! But after 7.5 inches of rain in 8 hours I’m off to repair my faltering sump pump. (The joys of home ownership!)

BUT, new heatsink paste for all my machines… as time allows. (I read somewhere that you should renew your paste every 2-3 years.) Yet, no mention of crack filling or flowing juices… (talkin' at you Mr. Happy!).

[nanopico]

Nano’s “Total Eclipse Pseudo Virus”

Wow I feel special.  Now I have a virus named after me!

[DieHard]

We have mentioned Arctic Silver thermal paste in other posts and for people new to utilizing it and installing it on a G4 Daughter board, See Japmac's detailed instructions here...

http://www.jcsenterprises.com/Japamacs_Page/Blog/9AE7FE0E-0CF2-4A7C-8003-489B282582BC.html

As a side note, try to avoid using too much and getting a bunch of thermal paste under the clear film coating layer that surrounds the CPU on the daughter board, because it will be impossible to clean out if it gets under the film... so the rule of thumb is to apply a very small amount that will spread just cover the CPU and not over-flow and to use the new high-tech non-conductive versions (Arctic Silver 5 or better).  Also, there is no need to spread the arctic silver evenly over the chip, a small chocolate chip in the middle will perfectly spread out from the pressure of the Heat Sink as long as both surfaces are clean and prepped.

If you are on a budget, use cheap dollar store "Goo Gone" (Critrus based) to remove old hardened thermal paste which cleans with absolute ease and then use Alcohol to clean the oily residue off the metal from the Goo gone.  Try not to scrape or make marks on the Heat sink metal surface or the Top metal plate of the CPU. The "removed" will get the old stuff off very easily but may take 3 or 4 passes.  Also the "Surface Prep" alcohol may need several passes also to fully clean the metal from oil.  Never touch the prepped metal as your stinky little monkey fingers will ruin the whole process.

This 2 step removal/cleaning approach is the same process you would do if you bought the real (and expensive) arctic silver cleaning kit.  The "Remover" compound is basically goo gone and the "Surface Prep" removes the residue from the "remover"

[FdB]

Thanks DieHard. Will check that link before addressing other machines. And yes, there was old thermal paste under the clear film coating which I (mostly) removed... carefully, using a very-very small strand of copper wire and opti-visored eyes. (Yup, I got the OCD.) And I'll use the Goo-Gone on the next effort as well. Thanks.

[DieHard]

Yes, you will never have to use steel wool of any kind again

Lastly, as I don't see this mentioned much, the Arctic silver will take about 1 week to fully make a good Micro-Seal on the surfaces ans will usually yield an additional 3 to 5 degrees cooling.

Testing the temp before the Arctic and then immediately afterwards is not a true reflection even though it will still make a huge difference, the max benifit will be noticed after 100 hours or so.

[FdB]

I thought a more lengthy "break-in" period might be necessary for more accurate temp effects. I was concerned about the steel wool use, but there was some "tarnish" on the copper heatsink that I could feel with my monkey-handed fingernail as a raised "stain" or residue from something. Maybe Goo-Gone would've dissolved it. Link you provided notes removal of the clear mylar film to remove old excess compound under it, and that it may not need replacing. (Not something I wanted to consider or even attempt.) And link also recommends 100% isopropyl alcohol as lesser percentages include some water.

[DieHard]

I thought a more lengthy "break-in" period might be necessary for more accurate temp effects. I was concerned about the steel wool use, but there was some "tarnish" on the copper heatsink that I could feel with my monkey-handed fingernail as a raised "stain" or residue from something. Maybe Goo-Gone would've dissolved it. Link you provided notes removal of the clear mylar film to remove old excess compound under it, and that it may not need replacing. (Not something I wanted to consider or even attempt.) And link also recommends 100% isopropyl alcohol as lesser percentages include some water.

I am sorry, for the tarnish we use a product called Tarn-X
https://www.amazon.com/Jelmar-TX-6-Tarn-X-Tarnish-Remover/dp/B0716HLLNX/ref=sr_1_sc_1?s=industrial&ie=UTF8&qid=1503777193&sr=1-1-spell&keywords=tanrx

The stuff removes tarnish off copper ad makes it look literally like brand new with just a wipe or 2; over the last 30 years we have tried many different/methods; both GPU and CPU heatsinks and tubes get brand new with no effort using this stuff.  An untarnished cooler will definitely transfer a lot heat better, I cannot give you exact temps, but we use this stuff often and it helps.  For the average user, all this may seem a bit meticulous, but if you have a few macs or PCs all this stuff is cheap, easy to store and comes in handy.