Fixing sliders & USB port on M-Audio Axiom Pro 49 keyboard

Last year I purchased an M-Audio Axiom Pro 49 keyboard from eBay. Although I had several 'keyboards' already, I didn't have a 'normal' midi keyboard, which I hoped this would work as.

The keyboard was described (on eBay, where I purchased it from) as being in good condition, but with two broken sliders. However, when I received it, the case was actually quite different (as unfortunately often happens with things bought from eBay). The USB port was very loose and to get the keyboard to work with my PC I had to hold the USB cable in at a certain angle, and stick something heavy on the cable to keep it in place. Some of the keys also make quite a 'croaky' noise when pressed, but they do seem to work okay.

Opening up the keyboard wasn't too difficult, but there are a lot of screws to undo. You don't need to undo the large black screws in the middle of the keyboard's underside, just all the other screws. With the screws undone you can remove the top of the keyboard.

After that you need to remove a few screws holding down a long metal bar that goes across the top of the keyboard. Then you can unscrew the board with the sliders, undo the ribbon cable that attaches it to the main board, and remove the slider board.

I unsoldered one of the broken sliders and found it was an Alpha branded B10K 45mm (30mm travel) slider pot. However, I couldn't find the exact same model anywhere. The nearest I could find is the RA3043F-20-10EB1-B14, which looks to have a plastic rather than metal lever. This is also available on Amazon: Taiwan Alpha Electronics RA3043F-2010EB1-B10K 10k8486; 1/5W PC Mount Linear Taper Slide (Pack of 3).

Although there are plenty of cheap 45mm length (30mm travel) B10K sliders on Ali Express, they all seemed to have the contact pins on the outside of the slider, and also be missing the two inner PCB mounting pins. The Alpha sliders used on the Axiom board have their contact pins a bit further in from the ends of the slider. The only suitable ones I could find on Ali Express were ALPS branded ones, e.g. RS30 Series ALPS Switch 45mm 4.5cm Mono B10K Slide Potentiometer Speaker Mixer Faders Shank Length 10MM, you can find more at the top of this page of search results, and the end of page of the same search results (at the time of writing): 45mm B10K search results page 3.

From eBay I managed to find a set of 4 unbranded ones that look correct: B10K Slide Potentiometer 30mm travel single unit 45mm Length short shaft x4pcs. These were $15 + $2 P&P, and what I purchased. The ALPS ones from Ali Express were $4.5 + $3 P&P ea. The Alpha ones from Amazon were $10.81 + $4.17 P&P. The Alpha ones from Mouser UK were only about £1.5 each, but they didn't have any in stock, and I suspect P&P would probably add quite a bit to the cost as well. The ideal purchase would have been this ebay listing for Alpha 45mm B10K 10K Linear Taper Slide Potentiometer, as that looks to be exactly the same model as is used on the Axiom slider board. However, they only had 2 in stock (which is the number I needed, but I preferred to buy from a source where I could order more in the future should the need arise). They are also much more expensive at $7 + $3 P&P each.

Getting the main board out to look at the USB port was a right pain, it's extremely annoying that the ebay seller didn't mention the broken USB. I only paid £15 for the keyboard though, so I didn't think it was worth sending back for a refund. To get the main board out you have to remove all the various ribbon cables that go into it, and they were very tight and difficult to remove. On one a wire end popped out of the connector as well (no, I wasn't tugging on the wires to pull out the connector blocks).

With all the connectors removed (and the board unscrewed) I could check the USB connection and see that the part with the contacts actually moved quite a fair way back when you pushed it. The female USB B connector block has 4 pins centred on the bottom, so I bought a pack of 10 of these of eBay for £2. I also bought a pack of 10 new slider knobs, since I will need to replace all the slider knobs to keep them matched. So the cost of the sliders, slider caps, and USB connector is actually more than the actual keyboard cost (though less when you include the postage cost on the keyboard).

When trying to find the replacement sliders needed for the keyboard, I found a video about repairing the Axiom 61 keyboard. That said that the individual sliders weren't available, and you have to purchase a complete slider replacement board from M-Audio. They said the cost was only $20, which works out much cheaper than buying the separate sliders anyway. However, it seems you can no longer purchase this board, and the places online that have it listed (but out of stock) charge around $60 + P&P and that price would also attract 20% VAT and £10 post office fee to import into the UK if it was in stock for purchase.

After receiving the sliders and USB connectors I replaced these okay. But the keyboard required the separate power adapter to be plugged in for it to work, when it is meant to be able to take power over USB. Investigating this I found that a component had been ripped off the board behind the USB connector. And I had no idea what type of component this was.

M-Audio's support was completely useless, telling me that I needed to get a replacement main board, which are no longer available. Thankfully I managed to get some help over at electronics stack exchange, where the missing component was identified as probably a ferrite bead. So bought several different values of those (not knowing which value was needed), making this keyboard even more expensive.

When looking to purchase the ferrite beads, I was first looking at Ali Express, but they were quite expensive. I then looked on Mouser, where you could purchase them individually very cheap. But postage was very expensive. Finally I remembered RS Components, a UK based company. Some of the beads on there were only available in very large quantities, but most were available as packs of 10 - 25. While I was looking I also noticed they had the correct slider for the keyboard, and at a decent price (I think this one: Alps Alpine 1 Gang Slide Potentiometer, ±20%, 0.2W Power Rating, Linear, Through Hole ).

So after disassembling and reassembling the keyboard many times, a large amount of time spent looking for the correct parts to fit (and quite a bit of time fitting them) I now have a working keyboard. The only thing I'm still waiting for is the caps for the sliders, which I think must be lost in the post. So I might have to buy those again.

Moving my PC to another case

About a couple of weeks ago one of the drives in my RAID array failed. I managed to find a similar drive to replace it on eBay, though not the exact same model of drive. From my research, so long as the drive is the exact same size (or larger) and same speed (RPM) then it should work fine.

I posted on this blog previously (Why did I do this?! (RAID)) about how I'd fitted the drives into my case (Corsair Air 540). When the replacement drive arrived last week I noticed that the drive temperatures being reported in the RAID console were around 50°C on the drives. And when I took the 'drive cage' out of the case they were indeed pretty hot.

My 'drive cage' (top right) in the rear of the Corsair Air 540 case

Although they had a fan in front of them and two behind them (push - pull configuration) this obviously wasn't enough. I suspect it's that there's not really anywhere in this half of the case for the fans to pull air in from. The front fan is on the rear of a backplane, so most of it is covered by the backplane circuit board, and then the backplane just has a few small holes in the front drive bay doors for air to get pulled through. (I don't normally have any drives in the backplane, so it's not also dealing with having to pull the air past hot drives before it even gets to the drives in my 'drive cage').

All 3 fans cooling the drives were also quite small, around 80 - 90mm. So when I swapped out the dead drive I temporarily ran the drives outside of the case with a couple of spare 140mm fans to keep them nice and cool. This actually worked pretty well.

But it's not really a permanent solution. I managed to procure an old 5U Server case from work, this can be used in rack or tower configuration and is made by PCI Case. In terms of total volume (space) it's probably around the same size as the Air 540. But it's longer and shorter. With a bit of modding, this allows mounting drives at the front of the case with 140mm fans in a push pull configuration in front of and behind them to keep them cool.

Everything else fits in nicely, though I had to swap my Quadro and RAID card slots. While I can't remember off the top of my head, I'm pretty sure the lowest PCI-e slot is faster than the middle slot, so it's a bit annoying to have to swap the cards over. But the bottom slot is right next to the bottom of the case, so the graphics card's fan wouldn't be able to pull in air very well if positioned in the bottom slot.

There's no provision for cable management on the case, so it's a case of zip-tying everything. It took me ages to get the cables looking reasonable, it was a right mess before!

The front 4 fans and the fan on the rear of the backplane I put into a fan splitter. After now having used the machine for a bit, I want to swap a couple of the fans. The pull fan behind the hard drives (on the right) is a Noctua Industrial fan, which I thought would be good placed there because it's so powerful. However, it can be quite noisy, and since it is on the fan hub, it's on the same PWM signal as the other front fans. So I intend to swap that with the rear case fan.

The push fan in front of the hard drives (not visible in the pic above) is a Corsair 3 pin fan. So that's also a bit noisy. I had to use this fan here as the Noctua fans with their square design won't fit in the same position as they block a peg on the front panel. I intend on getting a circular Noctua fan (speed and airflow specs look to be the same as the other fans I'm using, which are NF-AF14 PWM models). Just need something else to buy from Amazon so I can meet the £20 free postage limit. I guess I could get 2 of the circular fans to give a consistent look at the front of the case but I don't care too much how it looks.

The case only has one 3.5″ bay, the rest is all 5.25″ bays. I 'borrowed' a load of adapters from work, which I think are actually meant for floppy drives, but they worked for mounting the hard drives. It gives a lot more space between each drive than they had previously in the DIY 'drive cage'. For the RAID drives I mounted one in the 3.5″ slot, then 3 in the 3 5.25″ bays above that.

In the middle of the case is my backplane, which takes up 2 5.25″ bays. Then there's another single mechanical drive (connected to the motherboard SATA) below that. In the bay below that are 2 2.5″ SATA SSDs, each screwed in just at one edge of the bay. Then the area below that is empty.

You can also see in the above pic one of the smaller fans (that was previously cooling the hard drives in my old case) resting on the rear left corner of the case. This is screwed into side panel to pull in air towards the graphics cards. There aren't actually any mounting holes for the fan, but like in the previous case you can just screw it through the ventilation holes in the panel.

The rear fan I had to drill new mounting holes for as the mounting holes are for a smaller 120mm fan. The fan the case comes with is molex powered, no PWM. The ventilation holes just about cover the area of the 140mm fan though, and since 140mm fans are what I have, it made sense to make it so I could mount a 140mm fan there.

Drilling the holes took absolutely ages. I had also put my motherboard in before I remembered about drilling the holes, so I then had to take it out again (don't really want metal shavings on the motherboard). I also had to take out my motherboard again a 2nd time later - when I had the PC all ready to boot, I was plugging everything in and noticed one of the annoying bendy pieces of metal on the IO shield above a USB port had got bent down and gone inside the USB port. Very annoying and time consuming.

The only other thing to talk about from the pic above is the mounting method for the push pull fans in front of and behind the 5.25″ bays. Currently the front fans aren't secured, but once I've got the fans sorted properly I will cable tie them in place (there's no other way of attaching them).

The fans behind the drives are cable tied onto what I believe are some more 3.5 - 5.25″ bay adapters. They are only attached to the 'top' adapter. The top adapters are then attached to the 'top' of the case with twist ties. This allows undoing them relatively easily, so you can take the adapter off (with fan attached) for access to the drives hidden behind it. I had to drill an extra hole in each of these adapters to allow cable tying the fans to them at the wanted position. Again, this took ages as the metal is relatively thick and I don't have any specialist metal drilling equipment.

The same adapters are used 'below' (in rack mount configuration) each fan. These adapters are cable tied to the case, but the fan is not cable tied to the adapters. They just give a point for the fan to rest against. The adapters provide just enough extra distance for the fan to work without hitting the hard drive power and SATA cables. The bottom adapters are also used for routing cables through.

The above is a general top-down view of the interior of the case. I decided to go for 2 PCI-e 8 pin power cables to the graphics card, not sure if it'll make any difference from having a single cable plugged into both 8 pin sockets as I had before, but it can't really be worse.

This pic shows the fans behind the 5.25″ bays and the rear of the backplane in the center. Trying to manage all those SATA cables was quite tricky. The USB from the backplane doesn't actually go anywhere at the moment - it's not long enough to reach the USB headers on the motherboard, so I need to get an extension for it.

The BBU for the RAID card I just stuck to the case using some double-sided tape.

Looking at the front of the case you might spot a problem - no I/O. I may try and get a front IO panel that fits in the 3.5″ bay slot, but I'm 95% sure there isn't enough space for that due to the hard drive that is mounted in that slot behind the cover. The case does have 2 USB2 ports on the side (top in rack mount). But no headphone jack. So I've had to get out my M-Audio M-Track 2x2M audio interface for audio (this plugs into the PC via USB). I also have 2 USB3 hubs on my desk with the wires connected back to the rear of the PC.

The case does come with 5.25″ bay covers that are slotted / slatted with holes. They would fit in front of the fans okay, but they are more plastic than they are hole. Similarly, there is a front door for the PC with strips cut across it, but again it is more plastic than hole. So I prefer to leave both off for maximum airflow. When my sister's kids come over I can put the door on and lock it so they don't stick stuff into the fans. They only watch Peppa Pig on youtube anyway, so it's not like it should be needing lots of air when they're using it.

Another annoying thing that happened when I was putting the PC together in the 'new' case is that one of the SATA connectors (plastic bit) on a hard drive broke off. I've never had that before. I superglued the connector back on, though the pins don't sit flush against it. I managed to get the cable plugged back on though.

Ideally I'd like to get the Fractal Design Define 7 XL case that was recently released and a lot of youtubers have been giving positive reviews. It's by no means the perfect case for me, but it's probably the nearest to what I'm looking for that's available. Unfortunately it's pretty expensive, and as it's only just released you can't get a used one cheaper. Hopefully at some point I'll be able to do a completely new PC build using that case, but obviously a new PC will be pretty expensive. So I'll just manage with what I've got for the time being.