If the speedo doesn't work it's GOT to be mechanical. Broken cable? Mine failed twice. First time, the cable coupling at the speedo had unscrewed itself. Second time, the cable snapped. If both the mechanical speedo and the electrical light failed at the same time it could be (just guessing) that something exploded in the speedo, or it could be two separate faults :- blown bulb and broken cable. Unscrew the cable from the speedo, and see if it's broken. Check the bulb. Go one step at a time, and let us know what you find, because this sounds damn weird.
