PowerMac G4 MDD
- For more information, see this article's corresponding Wikipedia page: https://en.wikipedia.org/wiki/Power_Mac_G4#3rd_generation:_Mirrored_Drive_Doors/FireWire_800.
| This device is in the WorkNeeded:OriginalParts category because it was flagged as missing information on the original parts. It may have replacement parts listed but those cannot be assumed to be identical to the originals. If you have a list of the original parts, please feel free to add them by copying the relevant table from EditorsToolbox:Tables | 
|
The G4 MDD is the third and final generation of Apple's Power Mac G4s, named so due to its Mirrored Drive Doors. It was produced from 2002 to 2004, and is notable for being one of the last Macs capable of running Mac OS 9 (with some caveats).
| Preliminary Information | |
|---|---|
| Release Year | 2002 |
| Leak Risk | High |
| Batteries | One (1) PRAM Battery |
| Mounting Technology | Through Hole, SMD, BGA, Sockets |
| Capacitor Types | Aluminum Electrolytic |
| Destructive Entry | No |
Known Issues
Power Supply
The power supplies in these Macs are known for suffering from failed capacitors. A recap may fix these, but sometimes the problem could be with another component that has failed. There are means to also replace the PSU in these Macs with an ATX one, though generally this route will cause you to lose the 24v rail which is needed for ADC monitors to function.
Symptoms of PSU failure can include but are not limited to:
- Briefly powering on, then immediately back off (often accompanied by some clicks from the system)
- System only powering on after the PSU has been plugged in for an extended period of time (10-30 minutes) before attempting to start
Disassembly Notes
Please be careful when opening the power supply because there are high voltage capacitors inside which can cause great injury to yourself. There are 5 screws holding the housing together and 4 screws holding the fans that need to be removed. Once the screws are removed, the top part of the housing needs to slide away from the fans. After that, the fans can be disconnected from the fan control board (though they may be zip tied to adjacent cables).
There are four screws around the perimeter of the main board, after those are removed the board should be mostly free, though you may get hung up on a filter cap that's behind the AC input. This cap is only adhered to the board, not soldered to anything, so it can be broken free of the main board without having to worry about desoldering anything. At this point the board should finally be free enough to slide it out and flip it over to desolder the two wires going to the AC input, take note of the orientation for reassembly.
The fan controller board has capacitors on it that may need to be replaced (this is where C401/C402/C403/C405/C407 are located). Even if they don't, it is recommended that this board be desoldered and moved out of the way to allow easier access to the capacitors behind and around it, as these do need to be replaced. The fan controller board is held in with both solder and a decent amount of adhesive, it may prove difficult to get it free of the main board even once the solder and most of the adhesive has been removed.
NOTE: If you are replacing the PSU fans while you're inside it, pay close attention to the CFM of the replacement fans, and match the original fans! Otherwise you may cause your newly recapped PSU to overheat and fail.
Original Parts
AcBel API1PC36
This recapping guide is only for the AcBel 360w and 400w API1PC36 Rev. B power supply units. There are Samsung power supplies also for the MDD which this guide does not cover.
| Part Number on Board | Capacitance | Voltage | Diameter/Size | Height | Type |
|---|---|---|---|---|---|
| C3, C4, C5 | 100 µF | 450 | 0.7" | 1.6" | Radial |
| C7 | 220 µF | 35 | 0.3" | 0.64" | Radial |
| C8, C32, C401 | 47 µF | 25 | 0.18" | 0.46" | Radial |
| C10 | 2200 µF | 16 | 0.4" | 1.2" | Radial |
| C13 | 2700 µF | 6.3 | 0.4" | 1.1" | Radial |
| C16, C29 | 2200 µF | 6.3 | 0.4" | 0.9" | Radial |
| C21 | 3300 µF | 10 | 0.4" | 1.2" | Radial |
| C30, C55, C56, C402 | 0.47 µF | 50 | 0.2" | 0.45" | Radial |
| C35 | 470 µF | 35 | 0.4" | 0.8" | Raidal |
| C41 | 680 µF | 35 | 0.4" | 1.2" | Radial |
| C43 | 100 µF | 25v | 0.25" | 0.45" | Radial |
| C53, C57 | 4.7 µF | 50 | 0.2" | 0.45" | Radial |
| C59, C60 | 1000 µF | 10 | 0.325" | 0.76" | Radial |
| C403, C405, C407, C45 | 10 µF | 50 | 0.2" | 0.45" | Radial |
| C416 | 470 µF | 16 | 0.32" | 0.6" | Radial |
Replacement Parts
ACBel API1PC36
| Part Number on Board | Qty | Compatible Part Number | Order Links |
|---|---|---|---|
| C3, C4, C5 | 3 | 450HXW100MEFR18X25 | DigiKey Mouser |
| C7 | 1 | 35YXJ220MCA8X11.5 | DigiKey Mouser |
| C8, C32, C401 | 3 | REF0511470M025K* | DigiKey Mouser |
| C10 | 1 | 16ZLS2200MEFC10X25 | DigiKey Mouser |
| C13 | 1 | UHW0J272MPD | DigiKey Mouser |
| C16, C29 | 2 | 6.3ZLH2200MEFC10X20 | DigiKey Mouser |
| C21 | 1 | 10ZLS3300MEFC12.5X20 | DigiKey Mouser |
| C30, C55, C56, C402 | 4 | UPS1HR47MDD1TD | DigiKey Mouser |
| C35 | 1 | 35ZLH470MEFC(T8)10X16 | DigiKey Mouser |
| C41 | 1 | 35ZLH680MEFC10X23 | DigiKey Mouser |
| C43 | 1 | 25YXG100MEFC6.3X11 | DigiKey Mouser |
| C53, C57 | 2 | UPW1H4R7MDD | DigiKey Mouser |
| C59, C60 | 2 | 10ZLS1000MEFC8X16 | DigiKey Mouser |
| C403, C405, C407, C45 | 3 | 50YXF10MEFC(T1)5X11 | DigiKey Mouser |
| C416 | 1 | 16ZLK470M8X16 | DigiKey Mouser |
*TEMPORARY NOTE: The replacement part for C8/C32/C401 was listed as a 1000uF/10v cap, found here. I'm including it here as a just in case (different board revisions?). It looked to be the incorrect cap so it was replaced with one that matches the original's spec (47uF/50v). I'm in the middle of recapping one of these PSUs as we speak and will be testing this cap to make sure it works properly, and if it does, I'll remove this disclaimer. I just wanted to make a note of all this here just in case. If you're recapping one of these yourself, I'd double check to see what your original values are for these caps as a sanity check before you place your orders. -Xodium
If parts are not available or different selection is preferred, you can use the values in the Original Parts section to perform a parametric search. Replacement capacitors can be found on both digikey and mouser, or pick your preferred source.