about how to help a noisy G4 MDD to shut up and be cool in 4 steps

many people know it already: some Dual-G4s with MirroredDriveDoors (MDD) tend to have a little noise- and temperature-problem. when the CPU-temperature rises, the big fan kicks in and makes you feel like vacuum cleaning your office. Many attempts have been made for solutions. some of them are very Xpensive, others are simple and concentrate either on noise or temperature. many MDD-owners nearly freaked out with their machines. some started to mod their MDDs. and all of them used swearwords aloud.

but i didnt know that.

last spring i bought a used G4 1 GHz Dual MDD. it was a real bargain, so i couldnt resist. i soon found out that this beast was loud. by chance i got an original apple silent kit for a few francs (there’s still no euro in switzerland :-) and, for the moment, i was quite satisfied with noiselevel after the swap.
but i noticed the upper half of the case heating up quite much. also the PCI-bezels felt really hot after some hours of constant use. there is no exhaust for the hot air up there except through the powersupply, which starts to run hot too.
i had 3 harddrives, normally 4 pci-cards plus an additional DVD drive (due to region code things), all these devices help to heat the mac up.


1. Step

i first decided to pump some fresh air into the powersupply and the pci-compartment by placing an ordinary 80mm-casefan where the little loudspeaker used to be..



in order to do so, i had to dismantle the whole machine, strip the plastic covers off the metal case and drill up the speaker hole using an electric saw and a file.



the metal cases hole was then painted black, so its little imperfections could not be perceived from outside later, while the plastic cover’s hole would be framed by an unreal logo grille i just happened to stumble across that day :-)



i tried out several fans. first i had best results with a coolermaster with heat sensor but it started to vibrate after a few days :-( then i just picked a quiet constant speed fan.



the fan chosen (sticker’s off, dunno what brand) runs silently at 7 V now by connecting the +wire to the 12V and the –wire to the 5V lead of a Y-connector. i like to use shrink wrap to fit cables and connectors. its quick, safe and easy to handle. just twist the blank wires together and isolate them with shrink wrap. and these connections are impressingly persistent.



the speaker now sticks inside the upper case wall.



i didn’t put the plastic covers from the backside.of the machine on again. i thought that would improve airflow a little. it would also help with the 3rd step of my mod later.

the result is great. the PSU stays cool. even after 24hours of nonstop use it feels a little warm only, never ever as hot as before. the same happened to the PCI-card’s temp. (shame, i never took the effort of measuring those temperatures for comparison) i also noticed a clear drop in cpu temperature from 58.3 (thats where the big CPU-/Casefan kicked in every few minutes) to below 56 C.

this first part of my mod took me about 4 hours. the dismanteling and reassembling of the machine after having it thoroughly cleaned took most of the time, but that was necessary. i dont want to have any iron shavings kill my logic board.


2.Step



since the powersupply remained fairly cool even after running nonstop for several days, i chose to go a little further by digging out the old (loud) samsung-PSU, exchanging its noisy delta-fans with some titans i had laying around and reduce their speed with a little fan-regulator (fan mate).

<>
 
 the fan mate is mounted inside of the PSU cover. i drilled a little hole in the cover to get acces to the fanspeed adjustment knob. not very elegant solution but convenient enough. it later turned out that i can run those PSU-Fans constantly at lowest speed.

after swapping the apple-silenced-PSUwith my regulated titan-version, i noticed the G4 was now a little quieter. (i dont believe it would be good idea to reduce the fanspeed without having enough fresh air availlible near the PSU).

little effort, little gain. but ok; i can sell the apple silent kit to someone who is really in need.

(these first two steps of my G4’s evolution have been posted on xlr8yourmac.com already. thanks to mike and his great site)

 the system still ran fairly cool and less noisy than ever before. but after a few nights of lonely computing, the case fan got on my nerves and had to go. i chose a truly quiet panaflo FBA12G12M which ran fine. CPU temperature went up by 1 degree C (according to temperature monitor), but the silence was heaven.

but then summer broke in to little switzerland. and ambient temp suddenly rose to 28 C in my room and 61 C inside my mac! at 61 C things start to become critical for the cpu, so the cooling fan spins up. and i mean UP.  i then tried different case fans (including the stock delta and papst) resulting in either no significant improvement.or, then, in unbearable noise (in fact, the stock delta IS very powerful)

thanx apple: a bit of hot weather and my mac is nearly collapsing!
 .
3.Step



the most simple solution for the moment was to place a fan at the backside of the case, pumping the heat out of the mac. similar solutions had been tried by some modders all around the world before. i figured it had to be a 12cm fan, covering a larger area.


on first test run, temperature dropped quickly from 60 to 56 C after temporarily mounting the additional fan at medium speed!

being assured that this is the way to go, i thought about how to exhaust as much heat out of that case with minimal noise.  my decision was to mount two 80mm-fans plus one 120mm fan. you think those 3 fans wouldnt fit? they do!
right behind the heat sink is right enough space for two 80mm-fans. is this pure luck, or was this grilled area initially supposed to hold 2 fans and apple decided against it for cost reasons?? who knows...



i first mounted two coolermasters (regulated by a temp sensor) using some rubber-standoffs. very convenient. they just snapped into the grill and run silently at low speed. (one of them has been used in the speakerhole before. its vibrations are not audible when mounted with those rubber-thingies). so that was easy enough. (IMPORTANT UPDATE: after 2 days both coolermasters started to make annoying noises. i threw them away and mounted two powerful chinese no-name fans instead, connecting them to the optical drive fan connector on the mainboard. they work silently and temp stays the same.)



note that the plastic cover of the G4s backside must be removed to take full advantage of the perfect sized grill-holes.

the 120mm-fan also found its own corner where the harddrives sat before. with the help of a duct, it pulls the air from right over the heatsink directly out of the case.



i first tried that alignment using a prototype-duct made of cardboard after measuring the fan and the spacial environment in that cases corner thoroughly. the fan used is a papst 4312, which is fairly quiet, but can move a lot of air when needed.
 i then tested it half a night long with 28 degrees ambient temp and was happy to see CPU-temps stay below 56 C all the time.
and the loudest thing in the room was the ventilator i use to cool myself:-)



then i made a second, slightly modified duct out of thinner cardboard which i enforced with some glass fibres. quite a messy thing to apply, but it turned out to be a good material for the construction of that simple airduct. i soon stripped the cardboard off the now hard piece and smeared some more glass fibers to the other side too. i left it raw, only took a bit care ot the edges because this thing had to be isolated at the end. and as its not visible inside the case, i didnt put much effort in its design.



after closing some little openings in the case with aluminium-tape, i finally mounted the duct, taking care not to leave any leakage by using loads of acryllic isolation-paste.



mounting the DVD-tray turned out to be very tight. also the fan-grille i had put on the papst-fan to protect my fingers (that weren’t supposed to poke around inside the running mac anyway) proved to collide with the heatsink, so it had to be removed.

the papst is connected to the mainboard, along with the panaflo.



the harddrives were moved into the front bracket (underneath the DVD- and Superdrive-tray) but are still connectad to the ATA100-bus using an ATA-133-cable purchased in one local PC-shop. i dont care for the loss of two HDD- bays as i recently sold 2 of my 3 harddrives to buy one bigger deskstar instead:-) if i felt the urge to add one more harddisk, i would just throw out the 2nd DVD and use its bay or, then, place the additional disk on top of the Superdrive. (due to my 2.5cm thick speakerhole-fan, i cannot use full length-PCI-cards anyway. they would fit if i had used a thinner fan)



FYI: i also tried to use the same 120mm-fan in the same duct in reverse direction, blowing fresh air at the heatsink. this resulted in lower CPU-temperatures in short term, but temps rose constantly. i am not sure if it had to do with turbulences inside the case or with the fact that the rear intake is then right next to the two 80mm-exhaustfans and the PSU-outlet..
anyway. having one single airflow through the case with the intakes in the front and exhaust at the back gives stable temperatures when running the machine 24/7. thats  just what i observed.

finished now?
i thought so myself.


4. Step:

one black monday i had the bad idea to test an LED-lighted fan under the cool unreal logo. while tightening the screws, the acryl-frontplate cracked.

;

not a big crack but it really caught my eye. and the violet glim didnt make me happy either.
ok, i thought, The Way Out Is Through!



i stripped the acryl covers, bought some primer and paint and after some simulations in photoshop (shown below :-D) gave that unreal mac a new look.

it was quite simple. first i cleaned the surface with nitro. (the clear surface became blurred under that very strong nitro-stuff, so never ever use it for cleaning!) then i applied some plastic primer as it is used for car bumpers, before i actually could spray it black.
i chose black because it is most convenient. it looks good under virtually every desk, black paint is widely availible in case i damage or scratch the cover again one day and it really matches the MDD chrome parts.



my favourite color is turquois, but i figured i would never ever be able to find the same shade of color again, nor could i probably sell this G4 later when it’s turquois in color :-)

thats how it looks now in reality.

i also painted both rear covers. just in case i might want to remove the external fans and mount the cover again one day...
as so many times before, i think i am done modding this machine now. it runs and looks cool and it also runs siilently with a constant little whisper under my desk. and there is no second G4 of this type out there :-)

steps 3 and 4 took me about 2 nights plus one afternoon. i also spent some money for the parts and had an argument with my girlfriend who had to sleep alone while i was fiddling like mad.
but that was worth.

	17-03-2008 07:03
	holy ______ wow thats cool Guest

johnodd4

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