Adaptec Xhub4+ USB2.0 Hub
I reviewed Adaptec Xhub4+ here, but for those of you who can't be bothered to read the review this is what the thing looks like before undergoing macrosurgery. The intention is to change the green LEDs for red ones and see if I can't make the white translucent case glow all glowey. It sounds straight forward but it turned out to be more involved than you might think. A list of the parts used appears at the end of the article. Read on...
First thing to do is take the hub apart. Simple enough, just unclip the metal front and undo those four crosshead screws. This baby is built as ruggedly as a Chieftain tank and those screws needed a "real" screwdriver to remove them.
Once the screws are removed the top lifts off, as do the sides, revealing the circuit board complete with its own metal screen covering the components, including the LEDs I want to change.
Man, look at those diddy LEDs buried deep inside that metal case.
Here's a close up of one of the LEDs. That screen has got to come off!
Before we get down and dirty with this mod, here is a view of the inside of the top panel. You can see light guides are used to bring the light from those buried LEDs out to the front for your viewing delight. It seems everybody is using fibre optics these days!
These are the LEDs I am going to use to replace the originals. For those of you who don't know, these are SMT, (Surface Mount Technology), LEDs as are the ones I am going to replace. At 3mm long, 1.5mm wide and 1.4mm high, they are very small and very easy to lose! There are six LEDs on this board, 4 port activity, 1 power and 1 high speed indicator.
Ok, back to the mod. The next step is to remove the metal casing covering the circuit board. The casing is attached by twenty three of these little tabs soldered around all four sides of the board.
With the help of my trusty green solder sucker and a stout knife I was able to desolder and lever the casing off the circuit board, (Eventually), to reveal a little city of electronic dooby-flibbers and more importantly, gain access to those minuscule LEDs.
Look there's one there! Now before we go any further I must warn you that SMT components require specialised soldering tools and solder and in the absence of said items expect to destroy the LEDs when trying to remove them from the board. I don't have the specialist tool for these things but I managed to only destroy one of the six LEDs, but I do have a lot of experience at this sort of thing. So consider yourself warned if you plan on changing SMT LEDs on anything. If you do have the correct tool them I assume you know how to use it! For the benefit of those who haven't, to remove the LEDs first heat the soldered joint at one end whilst gripping and lifting the device with tweezers. Once the solder melts, quickly transfer the iron to the other joint and repeat. Keep repeating this procedure until the LED is unsoldered at one end then just heat the still attached end and lift away. This method takes some practice. Alternatively if you don't want to try and save the LEDs, just melt the solder at one end and lift LED away completely. This will generally result in ripping the other connection off the LED leaving it soldered to the circuit board. Just clean up the solder pads with the iron. Since the SMT LEDs are so fragile, you could just twist them clean off the board using a pair of pliers and just use the soldering iron to remove the remnants from the board. Very crude, effective and somehow satisfying!!
Right, with the old LEDs removed and the solder pads cleaned up it's time to fit the replacements. The polarity of SMT LEDs is indicated with a paint mark at one end. The green LEDs fitted to the board had the paint on the cathode end, BUT the new red LEDs were marked on the anode. It was a good thing I checked them with a multimeter first before soldering them! It is always checking things like this before committing them to the soldering iron. To solder SMT components I used a special low melting point solder cream. This is generally supplied in an applicator syringe. Unfortunately mine was several years out of date and had dried into a hard lump inside the syringe. I cut the syringe open with a knife to find the centre had not quite fully hardened so I was able to use a pin to scoop out some some cream and apply it to the circuit board.
As you can see it didn't exactly make the neatest of jobs, but not to worry it will soon tidy up when it is melted with the soldering iron. I used a small blob of "Blu tack" on the end of a cocktail stick to pick up and hold the replacement LEDs in position whilst the solder cream was melted with the iron. This somewhat "doctored" picture should explain the procedure. It was impossible to perform this procedure and take photographs simultaneously so I improvised.