View Full Version : MDD Case Cooling Kit, or, Heat Kills!

04-18-2003, 11:57 AM
More reports on MDD G4 Tower internal case/Drive Heat -
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>
Wednesday's news had a link to an AMUG article on MDD Dual 1.25GHz Superdrive and Hard Drive temperatures that sparked some readers to send their comments on their MDD systems. Here's one that noted a drive failure, although I can't saw how common this is (many may not run their systems 24/7):

" Speaking of internal temp problems...
I recently hosed a 200gig WD JB drive. I believe the reason is a combination of 3 things.

installing apples new 'quiet' case fan, which pushes noticeably less air then the 'old' one. (also as noted before here - the original PS was a 400W, the replacement PS is a 360W.)
having my pioneer dvd drive ripping dvds 24/7
having two extra drives in the left side expansion area blocking what little air flow is left..

The drive died from heat no doubt. It was not a case of directory corruption or some other file problem. The noise it made was not healthy at all. When I opened the case it was unbelievably hot. The processor heat sink, which sits right next to the right side drive expansion area, was so hot I could not touch it. Lucky for me the processors survived.. 2x867 MDD.

Needless to say I have changed things in my case. I took the 2 drives off the ata66 expansion and re-installed the old loud case fan. Now the heat sink on the processor is barely hot...

2 lessons.

Heat will kill drives faster than greased owl poop.
back up your stuff...

I lost 4 months of pictures of my kids and 55 dvd divx rips. And countless other bits and pieces I can't recall (that?ås the scariest part) .OUCH..hard lesson to learn.
If your case is packed be sure you got proper air flow or its only a matter of time before your machine will sing the clickity clackity song.
-steve "

Although it's not run 24/7, a MDD Dual 1GHz here (recently upgraded with the quieter PS/Fan kit) hasn't had a problem (so far at least) with a OEM 80GB HD plus WD 120GB (slave on primary bus), Superdrive and Teac w540 CDRW drive installed, but I've not run any drive temperature tests. I'm also considering opening up the metal shield near the superdrive's fan; even with the small vent holes in that shield area, it's still blocking some of the fan's airflow. (But the area I'd have to cut out includes one of the depressions used to remove the sheild.

www.xlr8yourmac.com (http://www.xlr8yourmac.com) 4/18/2003 <HR></BLOCKQUOTE>

Granite Digital does have a temperature gauge if you think it would help knowing!
www.granitedigital.com (http://www.granitedigital.com)

[This message has been edited by Gregory (edited 18 April 2003).]

04-18-2003, 12:32 PM
I saw that AMUG article. Early on with my G4-1.25G DP MDD I decided not to install the firmware update to quiet the noise down in OS9.2.2 and never have. When the kits were offered with 360W power supplies and quieter fans, I decided no again. Now that Apple does not want the 400W PS back, I will order the kit and just keep it as a backup, but hopefully never need it.

I have a Radio Shack digital indoor/outdoor thermometer monitoring temps inside both of my G4s as well as room temp. They also remember both the highest and lowest temps recorded. My QS temps is what helped me decide against any "downgrades" for the MDD. Highest temp recorded inside the MDD is 105.1F when room temp was 81.5F, QS is 102.6F when room temp was 86.5F. Princess hates A/C so I may have to get a room A/C to keep these puppies cool this summer. k

04-18-2003, 11:29 PM
Wow Kaye, I was thinking the same thing.

We have two MDDs that I could swap the PS on, but sound is not an issue; heat is. Cheapest backup factory PS we will every find, right?

Anybody think a case mod is worthwhile on these models? Will cutting the perferated sheat metal out to smooth/increase airflow per G's post really help much?

[This message has been edited by newbie (edited 18 April 2003).]

04-19-2003, 12:59 AM

Are your MDDs the original model or the FW800 model? Have you done the firmware update? I have a friend with the same G4-1.25G (not FW800) model I have except he did the firmware update and the machine runs much hotter that way and now he has just installed the kit and he says the fan is coming on high after awhile in OSX, running very hot, the first time he has ever heard it in X. Never ever heard it in X with the original PS and fans. I helped him with finding a PCI slot fan for the topmost slot and he sez it is pumping a lot of hot air. He is also looking to get some of those slotted PCI slot covers that the new MDDs have when they are available in the Apple parts chain.

I'm running more PCI cards than he is, four of them, and more memory, but he has the 23" Cinema HD Display which draws its power from the power supply. I'm just going to order the kit and put it in my parts bin. k

04-19-2003, 05:10 PM
From Louie:

Here's the letter (an email that I sent to AMUG and Breeden yesterday):

Michael and Mike:

I just read with interest the AMUG report on heat and the MDD Power Macs that was linked from Mike's xlr8yourmac site today.

I have a fall 2002 dual 1.25 MDD PM that now has the Apple "quiet kit". Below is a comment that was posted on MacInTouch about 10 days ago that I feel is related to the AMUG report:

¬?¬?¬?¬?¬?Yesterday I installed the noise kit in my Dual 1.25 GHz machine
¬?¬?¬?¬?¬?and it made a world of difference. For the first time I can hear
¬?¬?¬?¬?¬?the seek heads on my HDs.

¬?¬?¬?¬?¬?In my case, the original power supply fans were the biggest
¬?¬?¬?¬?¬?noise problem. That original PS is rated at 400 Watts and the
¬?¬?¬?¬?¬?dual fans are Delta AFB0612EH, 6800 rpm, 38 cfm. and 47 dba.
¬?¬?¬?¬?¬?(Noisey, high rpm to get a high cfm)

Last September, while trying to find a pair of quieter fans that also moved enough air, the closest I could come to the Delta cfm rating was the Evercool F126025DH, 4550 rpm, 32 cfm, and 31 dba. Although these were much less noisey, they moved considerably less air. Asumming that Apple engineers sacrificed noise to get the proper cooling, I was afraid to use the Evercools.

Now comes the noise kit. The new PS has a slightly lower rating of 360 Watts but the fans now are of a much lower rating than the originals. The new fans are Nidec BETAV, TA 225DC, model M34418-16 which have specs of 5150 rpm (thus much quieter), 25 cfm (much lower), 31.5 dba(much lower). Have they now sacrificed air flow to get less noise? We seem to have gone from one extreme to another. Makes you wonder.

The noise from the original Delta 120 mm fan never bothered me but I installed the new Papst fan anyway. The specs for the two are very close. The Delta has 7 blades while the Papst fan has 5 wider blades. It appears that the Papst fans were modified slightly to be able to snap into the Apple mounting system. (The frame is thicker than the Delta fan and two small areas were milled to fit).

Before the kit installation the exhausted air was noticably hot, but is even hotter now. My guess is that Apple went to the extreme trying to cool the 400 Watt power supplies with those very high rpm fans and may have gone too far in the other direction with inadequate fans in the new 360 Watt power supplies. With the original setup, the 120 mm fan never kicked up to the intermediate speed, but now does so quite often. I believe the new power supply is allowing more heat to build up in the case. My power supply may be a bit hotter than many because it is driving a 23" HD Cinema Display (40 Watts).

I'm about to try the higher spec Evercool fans in the power supply to see what results they give. I will get a temperature probe and will let you know if you like.

Yesterday I added a squirrel cage exhaust fan to the outlet for PCI slot 3 and it is pumping out lots of hot air while remaining quiet.


[This message has been edited by kaye (edited 19 April 2003).]