Dear MSX friends,
Many MSX models had an analog daugtherboard called "HIC-1" (aka "EMC-NX0039") that feature 3 SMD electrolytic capacitors with aluminum caps that are beginning to leak. Those capacitors electrolyte is particularly corrosive and badly damages the board around it. You can see how bad it goes in this topic.
This is the list of known MSX machines that feature this board inside (but there may be others):
- Sony HB-F1XV
- Sony HB-F1XDJ
- Sony HB-F1XDmkII
- Sony HB-F1XD
- Panasonic FS-A1
- Panasonic FS-A1mkII
- Panasonic FS-A1F
If you have any of the mentioned models, you should hurry and replace the following capacitors on the HIC-1 daughterboard:
- C10=10uF/16V
- C14=10uF/16V
- C22=100uF/16V
The worst offender is the C22. In many machines our group inspected it was beginning to leak.
It's possible to replace them with either electrolytic capacitors or more modern Tantalum or Ceramic capacitors. It's very advisable to replace them with the more modern ceramic versions, so you won't have to worry about this problem ever again.
Those are the appropriate specs if you're going for Ceramic or Tantalum replacements:
- 10uF: size 3216 (1206 in imperial unit)
- 100uF Ceramic: size 4532 (1812 in imperial unit)
- 100uF Tantalum: size 6032 (only metric)
All three capacitors must be rated for 16V or more.
It doesn't matter if your machine isn't being used and is stored somewhere in the attic. If those capacitors leak, it will be very hard to fix it. If you care for the machine, replace those capacitors ASAP.
Most hobbyists have an old one lying around somewhere, or can borrow/buy a 2nd one for peanuts. A soldering iron on both sides of the part, and when solder on both sides has melted, you lift the part up like the Chinese grab rice with their eating sticks. 
Who cares where it drops or whether it sticks to the soldering iron - it's off the board, you discard it anyway, job done.