PCI+to+PCI-Express+bridge

=PCI to PCI-Express bridge/adapter=

I envision two versions of this thingy. Both are basically the backwards version of this PCI-Express to PCI bridge adapter.

First is similar to a simle PCI32 riser card, but which has a PCI-Express slot on top instead of PCI32. Ack, someone may have already made this! Huzzah! Though I really wish it had a physical x16 slot with just the x1 connections, as nearly all larger cards will still function in a x1 slot, though expectedly with reduced performance. Someone else has now made this with a x16 slot plastics! Huzzah again!

The second version of this is a 90degree riser card, as may be recognized as a 1U2 case slot adapter, but again going from PCI32 edge to PCI-Express slot. This could be more useful to those with MiniITX cases with an expansion slot above and parallel to the motherboard, such as with MicroA1 or Sam440 boards to a PCI-Express graphics or whatever card. (Yes, I'm aware of MicroA1's issues with graphics cards, see uboot project for intent to fix that somehow)

As I'd use a physical x16 slot and only have the x1 connections, here are some slot possibilities: Digikey 1 edge straddle mount, is the cheapest one there and then rip out unneeded pins. Digikey 2 vertical through-hole mount, cheapest one there, and slightly cheaper than Mouser vertical one. It's not a straddle mount, but rip out unneeded pins and reorganize the needed ones, should be able to make a suitable straddle mount one. And also use it for the right-angle version.

Mouser 1 is cheapest there, and far cheaper than the Digikey straddle mount one. Datasheet for it. It's not a straddle mount, but rip out unneeded pins and reorganize the needed ones, should be able to make a suitable straddle mount one. And also use it for the right-angle version.

The Hack
OK, so I finally got two of these Startech adapters. While Startech sounds interested in the idea of another version of this thing with a x16 slot plastic with only x1 connections, it's not here now. So I plan to mod my two to have a x16 myself. I used a standard mount PCI-Express x16 slot from Digikey, as that seemed the least expensive choice. I did not order an edge straddle-mount, which is what we'll actually use, and is what is there from Startech, as that variety was a lot more expensive. There's plenty of pins in a standard mount slot that will be removed, and we can reuse. But order a couple slots in case you screw one up.

The VERY FIRST THING TO DO is to test your board as it comes from the factory and make sure it works. If you for some reason got a dead one, you can send it back for replacement at this point. If it fails to work after modding it, the whole thing goes in the trash and you have to pay for a second one. Understand that the moment you meddle with the board, all warranties are lost and you are on your own.
 * Step 0.**

Now, to the fun stuff...

First, I modified the slot. I'll mod the board with it later when I have more time. You do not need to worry about static on the slot socket itself, but do be careful and use a wrist strap when you're handling the PCB.

(Pictures coming soon)

The first thing to do is remove the outer two rows of pins. To do this, use needle-nose pliers to grip each pin, one at a time, at the bottom of the socket, and pull it straight out. There's a tiny bit of the pin which grips the plastic, btu that should give relatively easily. Start at the far end of the slot where you really don't care as much about what happens, as there will not be any pins there at all when you're done. ONLY do the two outer rows at this point. These outer pins will go in the trash, so they are good to practice on before doing the inner row pins we don't need, and those inner row pins are the ones which a few we'll save and reuse. As you're doing the outer row pins, try to get good at pulling it out without unbending/straightening the solder tail you're pulling on. The less it's deformed now, the less fiddling you'll have to do later to make them nice again. Set the pile of outer row pins aside or in the trash, they're no longer useful for anything.
 * Step 1.**

I suppose it is possible to leave the outer row pins in the positions we'll need pins in when we're done and rebend the solder tails to an inner row angle, but I did it this way, hoping that reusing the best removed inner row pins would be easier.

Now, look at and note where the original x1 slot pins end. Leave those same locations in place for our new slot, and remove the unused inner row pins behind that. Keep these inner row pins in a different pile than the outer row pins, we don't want these getting mixed together.
 * Step 2.**

Remove the plastic pegs from the bottom of the slot plastic. The board I have does not have a notch for them to fit into. True straddle-mount slots probably do not have these pegs. The peg at the no-pins end is relatively easy, but be careful removing the one surrounded by the remaining inner row pins. You don't want to mangle these pins if you can avoid it. Yes, you should have plenty of spares now to replace a mangled one with, but these remaining pins will have a stronger grip on the plastic than the repositioned pins will, and it's probably better to keep the total grip as strong as possible.
 * Step 3.**

Reinsert inner row pins to the connected area of the slot. These pins had been outer row pins that were removed, but are used by the x1 electrical connections. I found it easiest to get the pin pushed in correctly if a card was placed into the slot. The top tip of the pin goes into a small hole at the top of the slot, and having a card in place helps guide the tip into that tiny hole. Use the smallest needle nose pliers you can get, as now that the pin solder tails are all right next to each other, there's not much room for a big tool. Don't worry about getting things exactly right at this point, just get the pins pushed in as good as you can. And it's OK if they don't seem completely in yet either, we'll do some cleanup in the following steps.
 * Step 4.**

If you used a PCI-Express card to help guide your pins into place, remove that now and set it aside. You likely won't need that again during this project. If you have any pins that are still slightly "out", set the slot with the slot end down, pins sticking up. Use an Xacto knife blade to press any loose pins completely into place. You should be able to see that the pin is slightly wider just above the solder tail, and that wide spot is flush with the plastic for the pins that were not removed. You can press on either side of that wide spot to press the pin further in until it matches the unremoved pins.
 * Step 5.**

You may, like me, have solder tails point in a variety of directions. at this point. Use the needle nose pliers, Xacto knife, and whatever other small tools you may have available to coax those unruly pins into a nice orderly line for each row.
 * Step 6.**

At this point you should have a pretty decent looking slot. But you may find that these nice straight soldertail pins are spaced a little wider apart than this PCB is thick. Do a little more fiddling to press the two rows a bit closer together. If you have a small round tool, you can use that to form the soldertails into a slight curve, so that they will offer a little grip on the PCB, but have the tips a bit wider to help ease insertion of the PCB into place.
 * Step 7.**

You should now have a finished x16 slot with x1 pins that will fit pretty well onto this PCB.

Second, modify the PCB. You should only have to remove the factory slot and solder the one you modified into place.

Use ChipQuik component removal kit to remove the original slot. use a soldering iron and slather the ChipQuik removal alloy onto the slot pins where they are soldered to the PCB. Don't worry about shorting things, we'll clean that up later. Once the pins are well covered, allow the iron to melt the removal allow down into the original solder. This stuff lowers the melting temperature of the solder so it's easier to get off than just trying to heat up the original solder alone.
 * Step 8.**

Trace the iron back and forth along one side of the slot pins. Your goal is to get the whole side melted and slide it up and away a little. You may have to go back and forth from one side to the other, walking the pins up little by little until they come off the edge of the PCB and the slot is completely removed. While you need to keep things hot enough to melt and move, be careful not to get things too hot that the PCB suffers. You do not want to lift any traces here.
 * Step 9.**

Use solder wick to soak up all that solder/removal alloy. Clean things up as well as you can.
 * Step 10.**

Apply a small amount of solder to each pad on the PCB where the slot pins will attach. Not much though. Do pay attention to avoid shorting pads together. Use a magnifying glass or something to check for tiny solder bridges, some of these things can be hard to see with the naked eye.
 * Step 11.**

Place the new socket into place. Take care to line up the pins to the pads correctly, and to avoid going to far to the side that a pin may bridge two pads. Get the slot nice and flat against the PCB edge.
 * Step 12.**

Tack a slot pin on each end of each side, soldering them so they hold the slot in place. You should not need to add any solder, only use the small amount you coated the pads with in step 11. Check things are still aligned well and flat against the PCB edge.
 * Step 13.**

Solder the remaining pins to the pads. You may or may not need to add a slight amount of solder, try not to. The more solder present the bigger chance of shorts between pads. Do all pins at this point.
 * Step 14.**

Some people recommend slathering regular solder across each side, allowing everything to short together that wants to, and then use solder wick to remove excess afterwards. This is an acceptable method as well, and I've done that with PQFP package chips before.

Look very closely for solder bridges remaining between pins/pads. Use an Xacto knife to push these shorts out of the way. If you have a larger bridge, you may need to heat it up and wick it away, then check again and use Xacto knife if needed.
 * Step 15.**

Use some flux cleaner to clean that up, and you should have a nice pretty board ready to test. For the first test of your modified board, I recommend using the same x1 PCI-Express board that you used in Step 0 to make sure your adapter works. Once you're happy with that, plug in whatever it is you really wanted to put there, and happy adapting!
 * Step 16.**