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MDD Silencing Project

Z

Zoetrap

macrumors newbie
Original poster
Dec 3, 2010
21
0
Hello everyone! First time poster here. :)

So, we all know the G4 MDDs are very nice machines, but they do have a slight noise problem. So much in fact, that I find the machine quite hopeless to use (I hate noisy computers...), unless of course you have a well-ventilated, sound-proof room to keep the machine in, well away from your desk...

I've been thinking about solutions for making my MDD quieter and I thought I'd share my project here for anyone interested.

I've decided to replace the shady and noisy MDD Power Supply with an ATX Power Supply. I considered several options, like installing a Micro-ATX PSU, modding the MDD PSU with ATX internals etc...
However, I find Micro-ATX PSUs to be slightly more expensive than normal ATX ones and they often do not provide a sufficient amount of power, and I do not have the tools needed for replacing the MDD PSU internals with the ones from an ATX PSU.

And so, I decided on a normal ATX PSU, which then leads me to the problem on where to install it. I've seen solutions for mounting it in the "ceiling" of the case, but I don't really like that solution since the PSU might be in the way if you have a long expansion card installed. It also creates quite a cable-mess due to a lack of space.

After considering other options I finally decided to install it in place of the optical drive bay. I reckon I can live without an optical drive, and since the Superdrive in my MDD is failing anyway (can't burn a DVD properly, can't read CDs...), it's not much of a loss in my opinion.

So I bought an Antec Earthwatts Power Supply, an ATX extension cable, some shrink tubing and some cable-ties.
The Power Supply is rated at 430 Watts which is a tad more than the original MDD Power Supply, and since no power will be dedicated to the ADC system I reckon it might even be slightly overkill.


So, here are a few pictures from the project so far:


Where I'm going to install it. I still need to remove the small brackets that keep the would-be optical bay in place.



How it's going to look. I can use the MDD PSU securing brackets (marked with red) for fastening the cables with cable-ties.
I'm probably gonna fasten the PSU using velcro.
The stock case fan has been replaced with a Noctua fan. Should provide a decent enough airflow while keeping things nice and quiet.



Another pic of how it's going to look. I know the PSU exhaust fan is going to blow slightly on the CPU heatsink, but I don't believe it is going to be a problem. The Power supply I'm using should run relatively cool anyway.



Attached a cable-tie to the back of the PSU to route the wires upwards.



Tomorrow's work. Gotta be careful doing this... solering a wire incorectly could fry the whole thing.
 
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I can happily announce that the project has been a great success! :)

I still have a bit more testing to do before I consider it completely finished, but so far everything seems to be working just as well as before (well, except for ADC power of course) and deep sleep is working perfectly.

The only thing I'm not quite satisfied with is the cable routing inside the case. The cables are all out of the way and packed together in one place, but it still looks quite awful in my opinion. I know I am a bit of a perfectionist :p
I've been considering cutting off some of the unneeded cables from the Power Supply, but then again that would maybe not be such a good idea considering it's brand new.

Anyway, some photos of the progress and the final result:



Soldering time!



The brackets for holding the expansion bay have been cut off.



The final result!



Closeup on the cable mess...



View from behind, case open.



All in all I'm very satisifed with how it turned out. The machine is now nice and wonderfully quiet and operating temperature is OK. Maybe slightly warmer than before, but the case fan I installed doesn't have _quite_ as high airflow as the stock fan (Stock fan 108cfm max airflow, new fan ~93cfm max airflow).


If there are any questions, feel free to ask! :)
 
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I find this project great. I may sound goofy, but I do not have that much knowledge about PSUs.
I would like to do the same, I found a G4 on Ebay with defected PSU. Will I just have to cut of the connector from the original PSU and solder together with the cable ends of the new PSU?
How do I know which have to connect? Is it just connecting the same colours?

Thanks,
Mathias.
 
Cox Orange said:
I find this project great. I may sound goofy, but I do not have that much knowledge about PSUs.
I would like to do the same, I found a G4 on Ebay with defected PSU. Will I just have to cut of the connector from the original PSU and solder together with the cable ends of the new PSU?
How do I know which have to connect? Is it just connecting the same colours?

Thanks,
Mathias.
Click to expand...

Well yes, mostly it's just a matter of matching colours, but there are a few wires that are different. For example, an ATX PSU has a POK (Power OK) wire, which the powermac machines don't use. In this case you have to connect the POK wire to a +3.3v wire for it to work properly.

The color codes on the cables seem to differ slightly however (I used an ATX extension cable for this project, and the +3.3v cables were purple, while they usually are orange. If you have a situation like this, it's a good idea to also look on the ATX or MDD connector pinout as well).


There are many sites on the web on how to do this modification, for example: http://atxg4.com/mdd.html
There are also lots of other sites on the net regarding this mod as well (just search google). It's definately a good idea to do a lot of reading before doing this mod. I know I did.

And if you do go through with this: Check, double-check and even triple-check all your connections before plugging it in and powering up!! Get one wire wrong and you might fry both the Power Supply and the motherboard if you're unlucky.

Good luck!
 
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Thanks!

That sounds hard for me... I will definitely have to do muuuuch reading. So, I am on Google, now :)
 
I have an additional question.

If I buy a defective MDD, are there distinct symptoms that tell that it is really the PSU and lets one eliminate defective CPUs or mainboard?
 
Cox Orange said:
I have an additional question.

If I buy a defective MDD, are there distinct symptoms that tell that it is really the PSU and lets one eliminate defective CPUs or mainboard?
Click to expand...

I can't really help you with that, since I haven't done any work on a dead/defective MDD. The most common thing to fail on these machines is definately the Power Supply though. I guess you have to gamble a bit, unless you have the possibility to examine the machine prior to buying it. Examining the Power Supply and/or talking to the owner would probably be a good idea. :)



On to something slightly different:
My project has now turned into "MDD Silecing and Cooling Project". I had seen sites on the net where people had done cut-outs on the back plastic cover. I decided to do the same to hopefully improve airflow a bit.



I've cut out a hole using a multi-tool with a little cutting disc attached to it and have proceeded with sanding the edges.



Cut-out finished and everything put back together. I'm really pleased with how this turned out! :)
 
I feel a bit like thread-hi-jacking :) so I will just ad my last short insert. (I don't want to mess up this niece modding thread).

I've done reading and it seems the easiest symptoms are, that the power-button shortly lights up, when pressing and disappear, when releasing the button. If fans blow it is more likely the CPU or Mobo.

I had this nice one in mind with the many extension cards :)
http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=330500627608&ssPageName=STRK:MEWAX:IT
unfortunately I did not win. :(

Did you consider watercooling your MDD? :D Your Mod looks actually nice with the "cut out", as if it was intended by apple!
 
Cox Orange said:
I feel a bit like thread-hi-jacking :) so I will just ad my last short insert. (I don't want to mess up this niece modding thread).
Click to expand...

Hey, no problem. Ask all you want! :)

I had this nice one in mind with the many extension cards :)
http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=330500627608&ssPageName=STRK:MEWAX:IT
unfortunately I did not win. :(
Click to expand...

That looks like a really nice machine! Too bad you didn't win it though... but I'm sure there are others. :)

Did you consider watercooling your MDD? :D Your Mod looks actually nice with the "cut out", as if it was intended by apple!
Click to expand...

Thank you! :)

No I think I will stick to air-cooling (for this machine at least). I find it quite a fun challenge in itself to air-cool this machine efficiently while still keeping noise levels down.

Let's see what my next step will be. I've been thinking about adding another exhaust fan, but I need to figure out a good solution first.
I also think I'm going to fix the wire mess, making it look better.
 
A slight update:



I've re-done the cable routing a bit, and I think it looks much better now.



I've installed two Fractal Design 60mm fans in the front. They run on 5 Volts, so they are virtually silent. They still do a lot for supplying cool air to the case though.
 
I'm interested in making my Dual 1.25GHz G4 MDD PowerMac quieter, but not at the expense of losing my optical drive bays. I am hoping that there is another way to fix the noise problem by modifying the existing PSU, and replacing any of the other case fans that are guilty of making excessive noise.

Another option (though I have been told that it won't work due to the configuration of my MDD motherboard) is to put everything into another case, or even to make a custom case, but it is a shame to give up on the G4 PowerMac case, as it is really a marvel of engineering with room for up to 4 hard drives, plus the 2 optical drives. It isn't the prettiest beast to look at, but the use of interior space and the ease of access once it is opened is unique in all the case designs I have ever seen.

So, first task is to check for ways to quiet the PSU and then see if I can replace the other case fans with quiet models. If that option is not possible, I might have to get creative with some hand tools and a dremel, router, and drill and several sheets of Acrylic or Lexan.
 
Hmm... I've only had my 1.0 Dual MDD for a day and a half, and I don't think it's even remotely noisy, and yes, all the fans are working and it is dust free.

I have decided that I might upgrade the power supply in it so I can use the working one for the 1.25 MDD 2003 tower I have with a dead supply.

Now my OC'ed Pentium 4 PC? That's loud... it has a Thermaltake fan running at full power on the CPU. Of course, it is a 3.0 P4 OC'ed successfully to 3.6GHz, so it needs the high power fan. Runs cool at 88*F too.
 
cantthinkofone said:
Any updates? My MDD is driving me nuts!
Click to expand...

Nothing much has happened since the last update. I did a little cutting to further improve airflow at the back, but nothing big.
Oh, and I also had to replace the 120mm fan, because the Noctua fan needed a higher start-voltage than what was provided from the motherboard at startup (= fan not spinning). I replaced it with a Scythe fan. It's just as quiet, but it can also provide better airflow when spinning up to higher speeds.

The machine is wonderfully silent and runs nice and cool. :)
 
It's been quite a while, but some stuff has been happening lately! :)

I wanted to be able to use two displays with this machine (and improve graphics performance as well). Seeing as I've replaced the PSU with a normal ATX unit the ADC port was pretty much useless (unless I'd buy some sort of ADC->DVI adapter, which are hard as hell to find here in Finland, not to mention they seem cost a small fortune nowadays...).

So, I bought myself a PC ATI Radeon 9500 Pro (with 128MB RAM) card for teh cheap and went about modifying and reflashing it for mac use. An afternoon later and everything is up and running nicely!


Some pictures:


The card installed. Looking good!



In this pic you can see the power cord I had to manufacture for use with the card. It's a regular Floppy drive power connector soldered to a 4-pin molex. I just had to make sure the cable was long enough so I can open the case without hassle.


I'm really satisfied so far! I know I went slightly against my original "silent mdd" policy since this card has a fan (= more noise) while the original card didn't, but luckily the fan is relatively quiet. The increased graphics speed and the second display connector more than makes up for it anyway!


Complete specs:
Powermac G4 MDD Dual 1GHz
2GB RAM
ATI Radeon 9500 Pro 128MB
Digidesign Digi001 Audio Interface
USB 2.0 + Firewire 400 PCI Card (with D-Link USB Bluetooth adapter installed in internal USB port)
Realtek Gigabit Ethernet PCI Card
Mac OS X Panther 10.3.9 & Tiger 10.4.11 (Dual Boot)
Seagate 160GB HDD
Seagate 80GB HDD

Other mods:
Antec Earthwatts 430W ATX Power Supply
3x Fractal Design 60mm fans running at 7V
1x Scythe Slipstream 120mm fan
 
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