Q: Loud power supply in G4? Replacement?
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Jul 20, 2015 2:15 PMby Allan Jones,The original MDDs had a 400W power supply that sounded like a WW2 bomber taking off. The "fix" was to downgrade to a 360W unit that was actually quieter.
However, the fix was not a complete success. The 360W version developed a relative high failure rate. Today, many people who have been through two or more replacement 360W units would die for the reliability of the older 400W supplies, even with the noise issues.
Open the side fo the case and you should be able to see the label in the PS. If it says 360W, you have the quietest one and don't really have any options in the existing case. The PS was designed around the computer case, not the other way around as seen in a lot of Windows tower machines. Noting else will drop in.
If the PS you have now is labeled 400W, I would thank my stars and get some ear plugs. I'd much prefer the noise to an unreliable PS.
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Jul 21, 2015 6:34 AMby Allan Jones,As I said in my first response, the only PS versions for that model are either loud or potentially unreliable. Several vendors made them for Apple but they are the only ones that will fit your case. There is no "normal" power supply option unless you follow BDAqua's link, noting the following:
1) the cautions at the start of the article about things that stop working
2) the fact that the author gives no help for how to fit an ATX PS into your MDD case. The article mainly is about converting the wiring loom. See this important sentence at the end:
"At the moment, there is no real guide for how to install an ATX Power Supply in a MDD G4. It is tricky as the original power supply is not a standard size.
If potentially unreliable is a better option than noise, you can purchase and install the 360W PS from some parts vendors. It would be quieter and fit. Some 360W units work without issue. The one in my 1.25Ghz SP MDD has been doing legion service for 11 years--it is branded "AcBel." The one in my son's MDD was from a different vendor and lasted about five years. I cannot check the brand on that one because the old PS is packed away.
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Jul 21, 2015 10:18 AMby Jeff,Check out this article, that shows how one individual installed an ATX P-S in his G4 MDD, above the optical drive cage. From a practical standpoint, not designing every mini-tower chassis to accept a standardized power supply form factor was one of Apple's biggest blunders, and ultimately guaranteed a major headache for future servicing and parts replacement. A smaller fan that needs to move the same volume of air as a much larger one will have to spin at a higher RPM, which will generate more noise. The linked article shows the problem with suspending an ATX P-S at the front of the chassis, and not designing a means of directing the exhausted warm air out to the rear of the computer. As it is, that P-S's cooling effectiveness is comparable to a dog chasing its tail. There is no rear-mounted fan on that PSU, so the fan on the underside is drawing in warm air, which is blown through its rear ventilation holes, and some of the discharged air is drawn around and in again for round 2. The location of the PCI slots is another stumbling block preventing positioning of the P-S closer to the rear and above any components that are generating the heat that needs to be directed out of the computer's case. While his mod may work to his satisfaction, a little more time at the drawing board was needed for design/fabrication of a mini-duct from P-S to the rear of the chassis.
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Jul 24, 2015 11:29 PMby Glen Doggett,I recently replaced my failed PSU with one from the eBay seller, if you ship your old one back you get some trade in credit. His refurbished PSU are quiet and very clean, like new. In my original PSU I had replaced the cooling fans, I would not recommend this because you have to open up the PSU itself and work around some potentially dangerous electrical stuff that can retain lethal electrical charge after being unplugged.
There is another main case fan that you can replace with a quieter fan, but the connector on the motherboard does not match most standard cooling fan plugs, you have a two pin socket on the board and many fans have three pins, but you can likely get it to fit, if you make sure the correct two pins are connected, make sure the fan spins the correct direction. Not too hard to figure out. you could pull out the wires from the original two wire fan and replace the three wire plug on the new fan by carefully pulling our the little metal clip parts from the plastic socket and crimp the wires to those. I replaced the 120mmm case fan with a silenX fan, much quieter, but just about any other fan would be quieter than the stock fan. Vantec stealth fans are also good options. Many fans come with an adapter to use a molex power plug, this will run the fan at full voltage full speed full volume all the time. make the effort to rig up the connection to the existing mobo socket so that you get temperature controlled fan speed, quiet operation during idle CPU.
