Usually, repairing a device entails replacing a defective IC with a new one. But if you’ve got young eyes and haven’t had caffeine in a week, you can also repair a defective chip package rather than replace it.
There’s no description of the incident that resulted in the pins of the QFP chip being ablated, but it looks like a physical insult like a tool dropped on the pins. [rasminoj]’s repair consisted of carefully grinding away the epoxy cap to expose the internal traces leading away from the die and soldering a flexible cable with the same pitch between the die and the PCB pads.
This isn’t just about [rasminoj]’s next-level soldering skills, although we’ll admit you’ve got to be pretty handy with a Hakko to get the results shown here. What we’re impressed with is the wherewithal to attempt a repair that requires digging into the chip casing in the first place. Most service techs would order a new board, or at best solder in a new chip. But given that the chip sports a Fanuc logo, our bet is that it’s a custom chip that would be unreasonably expensive to replace, if it’s even still in production. Where there’s a skill, there’s a way.
Need more die-level repairs? Check out this iPhone CPU repair, or this repair on a laser-decapped chip.
A hundred years or more of consumer-level recorded music have moved us to a position in which most of us unconsciously consider music to be a recorded rather than live experience. Over a century ago this was not the case, and instead of a hi-fi or other device, many households would have had some form of musical instrument for their own entertainment. The more expensive ones could become significant status symbols, and there was a thriving industry producing pianos and other instruments for well-to-do parlours everywhere.
One of these parlour instruments came the way of [Alec Smecher], a pump organ, also known as a harmonium, or a melodeon. He’s carefully added a MIDI capability to it, and thus replaced its broken “Vox Humana” tremolo effect intended as a 19th century simulation of a choir, with a set of genuine human sounds. There is an almost Monty Python quality to his demonstration of this real Vox Humana, as you can see in the video below.
Lest you think though that he’s gutted the organ in the process of conversion, be rest assured that this is a sensitively applied piece of work. A microswitch has been placed beneath each key, leaving the original mechanism intact and working. An Arduino Leonardo has the microswitches multiplexed into a matrix similar to a keyboard, and emulates a USB MIDI device. It’s fair to say that it therefore lacks the force sensitivity you might need to emulate a piano, but it does result in rather an attractive MIDI instrument that also doubles as a real organ.
Continue reading “MIDI And A Real Vox Humana Come To A Century-Old Melodeon”