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 | 
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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.
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.
AcBel API1PC36
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.
Samsung PSCF401601B(C) Rev. B
Note: Documentation on this PSU is a work in progress.
With the Samsung label facing you, and the cables coming out of the bottom, there are:
- Three screws on the top side
- Three screws on the bottom
- A single screw on the back, close to the AC input
- A single long screw between the two intake fans, nearby the screw hole to mount the PSU inside the MDD (This is a long, fine thread screw. If you see a thick, coarse thread screw typical of a fan screw, you've got the wrong one.)
Once those are removed, lift the top (the part with the Samsung label) slowly away from the bottom half, lifting from the fan side.. You'll need to disconnect the the two fans from the main PCB, and they'll come away with the top half of the PSU. The AC input isn't soldered in, it can be disconnected from the main PCB. You'll also need to remove a screw that secures the ground wire to the rest of the PSU. At this point the top half should now be completely free and can be removed.
There are three screws around the perimeter of the PCB (one of them was the grounding screw) and a plastic rivet in the center of the PCB holding it to the bottom case. This rivet is easily defeated with a set of forceps or needlenose pliers and a careful hand: Reach in with your tool of choice, pinch the rivet and lightly pull up on the PCB as you do. The rivet should pop through the PCB and the PCB itself should now be free of the bottom metal casing.
Original Parts
AcBel API1PC36
| 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 |
Samsung PSCF401601B(C) Rev. B
(Placeholder, cap mapping of this PSU is in progress.)
Replacement Parts
ACBel API1PC36
| Part Number on Board | Qty | Compatible Part Number | Order Links | Possible (active) replacements |
|---|---|---|---|---|
| C3, C4, C5 | 3 | 450HXW100MEFR18X25 | DigiKey Mouser | |
| C7 | 1 | 35YXJ220MCA8X11.5 | DigiKey | |
| C8, C32, C401 | 3 | REF0511470M025K | 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 | URS1HR47MDD1TD |
| C35 | 1 | 35ZLH470MEFC(T8)10X16 | DigiKey Mouser | |
| C41 | 1 | 35ZLH680MEFC10X23 | DigiKey Mouser | |
| C43 | 1 | 25YXG100MEFC6.3X11 | DigiKey Mouser | |
| C53, C57 | 2 | UPW1H4R7MDD | DigiKey Mouser | ESH475M050AC3KA |
| C59, C60 | 2 | 10ZLS1000MEFC8X16 | DigiKey Mouser | |
| C403, C405, C407, C45 | 4 | 50YXF10MEFC(T1)5X11 | DigiKey Mouser | EEU-EB1H100SH |
| C416 | 1 | 16ZLK470M8X16 | DigiKey Mouser | 16YXJ470M8X11-5 or REF0816471M016K* |
NOTES
"Possible active replacements" refers to active replacements for parts that are marked as obsolete/obsolete and out of stock, or parts that have reached "last time buy" status. These have not been tested, only found by doing a search for the closest match to the original replacement parts listings. Some of these may be higher voltage than the original caps, this should be fine.
For C416: The lead spacing might be off for this one, but it should, in theory, be fine. There are two different caps listed here in case of store preference. The Rubycon 16YXJ470M8X11-5 is available at Digi-Key, but not Mouser. The Kyocera-AVX REF0816471M016K however, is available at both.
Samsung PSCF401601B(C) Rev. B
(Placeholder until cap mapping is complete)