Are all MDD power supplies interchangeable within each MDD model type?

Hi, yes they are.

Hi Patrick
Do you still have any of your PSU's please?

Remember however, that the 400 watt power supply unit is very noisy and loud.. the 360 watts are the replacement, quieter power supplies which are found on later MDDs.

Hi Patrick,
Any chance that I could purchase one of those power supplies from you? Thanks.

Then again ... needs must when the Devil drives. In my part of the world, even used 360-W PSUs are scarce and pricey. However, I found new 400-W supplies at a digestible price for my two MDDs. I transferred the 40-mm fans from the supposedly quieter 360-W PSUs to the 400s, and placed thin rubber shims between their bodies and the case-metal. The result? The MDDs are quieter than the DA beside them.

Hi guys
I'm about to swap out a 360w samsung unit and replace with a 360w AcBel unit (from the same spec G4 MDD FW800). I've compared all the output values of both and are identical apart from the voltage range at the top of the sticker which on the Samsung is 6.5/3.5A and on the AcBel it is 7.0/3.5A. Both display a MAX total wattage of 108w. Do you think they are interchangeable please?
Cheers!

Has anybody observed any difference in noise, functionality or reliability between the Samsung and AcBel 360W power supplies for the MDD/FW800's? I noticed that, on eBay, the Samsungs are rarer and generally somewhat more expensive.

The noise level of an MDD is, unsurprisingly, an interdependent amalgam of the contributions from CPU (heat output), 120x120 fan speed, throughput of air and noise (cooling effort), 60x60 PSU-cooling fans which I misdescribed as 40x40 above (noise), heatsink (cooling effort), thermal paste composition (cooling effort), AppleFan.kext (fan speed control), and Napmode script (CPU duty cycle and heat output), the sum effect of which can be shown by Temperature Monitor, Activity Monitor and Hardware 'control panel' (from CHUD) in System Preferences.

My dual (now 1.42GHz) G4 MDD settles during moderate activity (as shown by Activity Monitor) at about 25°C in an ambient of 16-18° (winter) or, currently, 30° in an ambient of 24° (spring). When it was a dual 1.0GHz with aluminium heatsink and no-name thermal paste it reached over 50° regularly with the same moderate activity in an ambient of 30°.

I modified the .kext after

http://www.s155158671.websitehome.co.uk/applefankextmod.html and
http://homepage.mac.com/paul74/MDDFanExtensionMod.htm

but lowered the range with the same intervals. I downloaded Apple's CHUD 3.5.2 for the CP Hardware, which I use with Tiger and Leopard on different HDDs in the same MDD. Hardware misreports the L2 and L3 cache sizes under Leopard, but does not disable them. The CHUD script NapMode (for which there is a mod. to use under Leopard) is discussed at

http://www.xlr8yourmac.com/feedback/MDDCHUDfeedback.htm

and Temperature Monitor is found here

http://www.bresink.com/osx/0TemperatureMonitor/screenshots.html

I use a copper heatsink over a minuscule film or 'smear' of Arctic Silver (enough only to fill the microscopic irregularities between the processor die and the heatsink). Treatment of the PSU's fans is mentioned in the post above. The fan for the heatsink is the original Papst fan. Inherent differences between AcBel and Samsung PSUs are, I suspect, overwhelmed by the modifications to software and hardware. Made carefully, the modifications work well.

Denis Eddy wrote:
...I transferred the 40-mm fans from the supposedly quieter 360-W PSUs to the 400s, and placed thin rubber shims between their bodies and the case-metal. The result? The MDDs are quieter than the DA beside them...

Does anyone happen to have any specs (part #, RPM, CFM) on the 40-mm fans from the 360-W PSU? Are those fans, or ones with similar specs that fit in the 400W PSU, available separately somewhere?

Many thanks. I think I might try doing a 40-mm fan swap in my MDD's 400-W PSU, just not sure what fans to get that will be quiet and still get the job done.

I'm curious as to if you still have any of those 360w PSUs left? You're email isn't listed anymore or I'd send you a message that way.

I went to turn on my 6 year old trusty FW800 and the power button lit up momentarily without any noise, dimmed, and now nothing happens. I've changed out the power cord, reset the PMU, reseated my memory and graphics cards, replaced the battery. I then bought a multimeter, battery checks out ok while in place, power cord checks out ok, PSU gives me no readings whatsoever. So...I'm just assuming I'm going to need a replacement PSU.

Please let me know if you have any more available, thanks!