This is my first post on CNC Zone.
I converted my Smithy lathe/mill/drill to CNC 2 months ago using a Xylotex 3-axis board for control. I'm enjoying learning everything I can and with my limited knowledge I believe that I really made the right choice with the Xylotex.
Unfortunately, one of the wires to my z-axis motor broke while the machine was running and I fried the z-axis part of the Xylotex board. I emailed Xylotex and was promptly given a very reasonable cost for repair. Figuring that this entire project is all about a do-it-yourself attitude, I decided to try and repair it myself. The repair cost estimate was more than fair, but I reasoned that if it happened once it can happen again and I don't want to wait for shipping/repair if another motor lead snaps on me. Worst case I could dump the old board off on Ebay (defect disclosed, of course) and buy a new one.
The main chip for each axis is a self-contained stepper driver in a 44-pin plcc surface mount package. I'm pretty good with a soldering iron, but I know that surface mount components require specialized rework equipment. To remove a chip like this, a special soldering iron head fits precisely over the chip and heats the pins until the chip can be twisted free from the board. In the abscence of such a tool, I used the more barbaric approach of a butane torch and tweezers. If the junction chip wasn't roasted before, it sure was when I got it free of the board!!!!
I found the replacement chips online for a few bucks each. I ordered several of them and with shipping it came to a few pennies less than the quoted repair estimate. Private Message me if you want details on part number and supplier.
I touched up the solder pads on the board with braid and a clean iron, and then soldered in the new chip. These pins are incredibly tiny and it took several careful passes to make sure each pad had good contact. I tested continuity of each pin to its facing circuit trace, and tested to make sure I hadn't shorted any of the pins together. The whole repair took about 2 hours and works well.
I'm posting this first to thank the manufacturer for offering what I feel is a great product at a great price, and second to show that repairs are possible if you are in a big hurry and have the ability to do so. I've posted this as information only and would recommend attempting this repair only if you have the skills and are willing to risk further damage to the board or the machine. You won't save any money doing this on just one repair.
Good job Steven,
I feel pretty confident that Xylotex uses the same cotroller chip as I do one one of my open source boards here: http://webpages.charter.net/pminmo/cncelectronics.htm
Yes pulling the 44 part is tough. For others that might try the same, the leads can be cut where the lead goes into the plastic with a utility knife fairly easily. By cutting all around the part, you can remove the plastic then just leaving the surface mounted pins. They come of pretty easy with a soldering iron by themselves.