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handheldgames

macrumors 68000
Original poster
Apr 4, 2009
1,939
1,169
Pacific NW, USA
Like many MacPro users, I need additional power inside my PCIe/Drive bay for additional components, such as PCIe USB3.0 cards, etc.

While I already tapped the power in the DVD bay, I would rather tap the power at the source: a 4Pin mini molex jr female motherboard header, located at the front of the MacPro case, by the 2 DVD power headers.

Ideally, we need a 4-Pin Mini Molex Jr cable with male/female connectors to tap into the power with an additional 4-Pin female molex tap that can be extended as needed inside the case. I have searched and can only find the components, not an assembled cable.

Has anyone else gone this route? Would be interesting to hear your solution. I'll be ordering the kits tomorrow to hand build a couple sets.

11247171106_075_p.jpg
15-97-5041.JPG



Thx,
HHG
 

handheldgames

macrumors 68000
Original poster
Apr 4, 2009
1,939
1,169
Pacific NW, USA
Pictures are an excellent idea. Ill snap some pics when I get home from work. The power header sits near the upper left corner of the motherboard to the left of the PCIe bay fan. I found it when I was looking for a power source for two fresco logic based USB 3.0 connectors.

The fan can be easy unscrewed and pulled out to reveal the connectors. It's power connector is integrated into the housing making reinstallation a snap. The only gotcha is aligning the PCIe release bar, which is super easy.

Tapping the power at that location makes more sense than plugging and routing a power cable from the optical bay.
 

Erlang

macrumors member
Dec 23, 2009
97
18
SW, UK
Pictures are an excellent idea. Ill snap some pics when I get home from work. The power header sits near the upper left corner of the motherboard to the left of the PCIe bay fan. I found it when I was looking for a power source for two fresco logic based USB 3.0 connectors.

The fan can be easy unscrewed and pulled out to reveal the connectors. It's power connector is integrated into the housing making reinstallation a snap. The only gotcha is aligning the PCIe release bar, which is super easy.

Tapping the power at that location makes more sense than plugging and routing a power cable from the optical bay.

Okay without pulling my set-up apart to have a look, I have a gnawing feeling this is the Fan unit power, how can you tap it without surgery to fan connector?

Maybe the photo's will help.
 

ActionableMango

macrumors G3
Sep 21, 2010
9,612
6,907
Edit:
Wait, I'm confused. Your text talks of mini-molex to molex, but your picture shows a black PCIe power connector.

I thought the PCIe power pin are all 12V. Molex 4-pin has 12V and 5V. If you are talking about using the PCIe power ports to power molex devices, you should make sure those molex devices do not need the 5V line.
 

handheldgames

macrumors 68000
Original poster
Apr 4, 2009
1,939
1,169
Pacific NW, USA
OP means this one, I think:

4QKDOiQVc1GQllMG.large


AM: connectors on pic aren't PCIe.

PCIe connectors on the MP motherboard are MiniFit Jr dual row 6 pin connectors. (between SATA and Mini Molex 4 Pin connector for the PSU Fan) The power connector for the Optical Bay is MiniFit Jr dual row 4 pin and it's in a great place to grab an additional power line.
 

handheldgames

macrumors 68000
Original poster
Apr 4, 2009
1,939
1,169
Pacific NW, USA
More of a repurpose than a misuse. Optical drives followed the path of the floppy years ago ago. I've been too busy with work to build one. I have a power cord that's snaked through the bowels of my the DVD bay for now, just needs to be replaced sometime eventually..

Why do you good folks seem always to want to misuse your machines?
 

Tesselator

macrumors 601
Jan 9, 2008
4,601
6
Japan
k, just don't forget and hook up a USB 3 device (or two) that draws more than that connector can supply. :p
 

popcorn-in-sac

macrumors regular
Jan 30, 2008
133
43
Seattle, WA area
I also recently ran power from the optical bay to supply to the Orico 4-port USB 3.0 PCIe card. This thread interested me, so I started looking into it myself.

It turns out that the connectors used on the motherboard for ODD power aren't Molex Mini-Fit Jr., but rather Micro-Fit 3.0 connectors. They are just a little bit smaller, and also have a slightly different configuration on the way the square "pins" are angled on their corners.

The link to the connector used is here.

I couldn't find a kit with all the components in a neat package, so had to order the male/female connectors and male/female pins separately, along with the crimping tool.

This just seems like a better solution, with less wire required. I just ordered the parts, so it will be a while before I try and build the cable assembly.

Mark
 
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