[weblacky]

OK so good, you noticed that they've changed the order of the pads on the PCB! That is exactly why I wanted you to check that, don't go by color first go by pad stenciling, if it's available. In this case black and red appeared to serve the same functions as they did in the old fan. So that definitely makes it a lot easier.

But again to be clear, on your old fan you have a red wire going to the plus pad. You want that same red wire to go to the new plus pad on your new fan. You have a black wire on your old fan that goes to the negative pad, you want that same black wire to go to the negative pad on your new fan, the last pad being where your yellow wire will wind up.

So what you stated is correct and yes I am advocating that you removed the old fan's wires, then remove the new fan wires, and attach the old SGI fan harness (wires) to the new fan body (PCB) using the correct pads but the old colors! This will mean you do not have to fiddle with the connector that goes to the SGI Origin mainboard. The connector is already pinned out correctly on the SGI fan cable!

So you will strip both fans of their wires as best you can by desoldering them and removing them, intact. You will then fish the old SGI fan harness correctly through the body of the new fan and get things in position, using tweezers and pre-tinning, and reconnect the old SGI fan harness to the correct signals on the new fan, as we've discussed above!

It makes a complicated thing incredibly simple, you don't have to worry about that fan connector on the board if there's nothing wrong with the connector. The signals will be in the correct order because you mapped the original SGI wire colors to their signals on the PCB. You don't care about order, they've obviously changed the order but you don't care about that. As long as you get the right color wire on the right signal on that fan PCB you're going to be just fine.

If you think about it this was a lot simpler than converting colors, snipping wires, or having to use a micro tool to gently push in the pins of the connector and rearrange them to meet the SGI standard. If there's nothing wrong with your old fans wire then it's ready to go now.

It's also important that some SGI systems use a large connector for a series of fans, all in one. The SGI fuel does this, instead of replacing that connector you're going to reuse the wires to change fans out. So this technique is going to work no matter what you encounter in the future as long as the original was working and untampered with. Reusing the original wire harness is almost always preferred to the new one. The only time that's not going to be true is if there's damage, somebody's been there before and so it's suboptimal, or the plastic fan connector actually cracked and broke due to age or heat. I've seen those kind of things and at that point you have to go further to get everything back in order. And your case swapping the fan cable assembly and soldering those three wires to the correct pads are going to be exactly what you need with very minimal risk.

In terms of soldering, I don't know your proficiency but I'll give you these hints/tips:

1. Completely desolder the wires from both fans first, gently removing them and setting aside the wires you will not be using so you will not confuse yourself.

2. If you end up melting a little bit of the fan wire or having any breakage or problems you don't want then you'd have to trim back all the wires to account for the damage and you'll want to pre-the wire if you've been forced to cut it. This also means you'll require flux at that point.

3. To practice, remove the old wires from the old fan first. You're liable to melt some of the fan's body trying to articulate the iron in the small space. Better to do that on the old fan than your new one.

4. I don't personally think you need to remove the old solder and clean and apply new solder in this scenario. Most of the time I would advocate that but in this specific case I don't think it'll get you anything and at worse it'll give you more opportunity to touch the hot iron to places in the plastic you don't want, so after you remove both wires spend the extra time properly routing the old wiring harness into the new fans wiring channels and get everything lined up. Don't worry about replacing, cleaning, or adding additional solder. I don't think you'll need any more than what's already going to be left behind. Obviously you have to tinned soldering iron to create a heat bridge but I don't think you need to copiously add extra solder for the joint.

5. The easiest way to solder has to do with knowing if your right handed or left-handed. Assuming your right handed it's easier to go from left to right or top down. So what you should do is turn the fan around 90° counterclockwise from the picture shown so that the wires and the PCB lineup with your left hand/arm.

6. It'll be easier if you slightly pull the wires you're not working with back out of that last retention clip to free your PCB area of any wiring you're not currently soldering.

7. I recommend that you go from top to bottom, assuming you're right handed, and do the wire farthest away from you first. You want to grip the wire with a pair of tweezers and you'll want to put some heat with a solder bridge onto the pad you expect to be soldering to and you want to introduce the wire into the blob and then remove heat, remove your iron, keep holding with your tweezers for a few seconds until it's solid.

8. Repeat that with the wire adjacent to the top most one and work your way down with the same technique. If you have all the wires in the area at once and try to solder them in series you run the risk of melting their plastic insulation coating or attaching the wrong wire to the wrong pad. Work with one wire at a time and then introduced the next wire, and so on.

9. You want to test the fan before you reattach the label. I would recommend you use a small amount of crazy glue or if you have one of those small dots or rolling tape dispensers for sealing envelopes that's another great option. You want the label to sit nice and flat and cover approximately what it was doing before. You'll need to add adhesive to do that but you will want to make sure your fan is working before you do it as you won't be able to lift the label up as easily ever again.

Go slow, and if you get shaky just take a break. It's not a race, it doesn't matter if it takes you 20 minutes to do this!

Obviously you should test without the fan installed in it's final place, because you still need to reattach the label. After testing and after you have already attached the label make sure you put the fan in the correct orientation so the airflow goes in the direction it's supposed to. Use pictures or other evidence to double-check that the airflow is correct and you didn't accidentally install the fan backwards.

Then you're done!