Matsushita JU-253 floppy drive dual switch replacement by Wierzbowsky

Last crawled date: 3 years, 3 months ago

I've seen quite many broken floppy drives in Yamaha YIS-805 MSX2 computers. Those drives are Matsushita JU-253 (JU-253A161M) and the weakest point in those drives is the microswitch that is used to detect the presence of a diskette and it write protection flap. There's no one-to-one replacement as these switches were only produced for those drives over 20 years ago.
Thanks to a piece of advice on the Russian forum, I've located a more or less widespread PC floppy drive where a similar dual pin switch could be found: Mitsumi D359T5. The drive actually has 2 of them! So, it's possible to fix 2 Matsushita floppy drives by sacrificing one Mitsumi drive. The switches can be easily removed from the Mitsumi drive - you just need to heat up the 3 solder points and move the switch forward.
I created the 3D model of the holder for the dual pin switche so that it could be easily installed into the Matsushita floppy drives. To replace the switch the following needs to be done:
clear switch's pins from solder
bend all 3 pins downwards
solder a thin wire to each pin (make sure there's not to much solder on the pins!)
slide the switch into the printed holder
put a piece of electric insulation tape on top of the pins (this is important!)
place the holder with the switch to its designated position (see photos)
use a 2x5mm screw from the bottom of the drive to secure the holder
Please make the original hole in the aluminium body a bit larger for the screw to go through. Then the installed switch needs to be connected to the drive's circuit board. See the photo of the wiring for reference.
As there are several versions of the JU-253 drives, the model of the holder may need minor adjustments. This 3D model is for the JU-253A161M drive that was used in Yamaha YIS805/128 and similar MSX2 computers.
If you want to make a small donation in appreciation of my humble efforts, please use the "Tip designer" button on this page:
https://www.thingiverse.com/Wierzbowsky/designs