Vulnerable MSX hardware
This page was last modified 21:48, 20 March 2022 by Grauw. Based on work by Mars2000you and Wild Penguin and others.

This page describes MSX hardware which has an above-average risk of failure on certain components. Owners of these should inspect them and ideally replace components as a precaution to avoid damage.



All MSX2 and up computers have a battery to power the RTC (real-time clock). Sometimes removable in a separate compartment, sometimes soldered to the board directly with either a plastic casing which provides some protection or bare. Some cartridges with SRAM for save functionality (e.g. FM-PAC) also have a battery inside.

Once fully drained these can start to leak corrosive fluids, especially alkaline batteries. To avoid damage empty batteries should be replaced or removed. If the MSX has removable batteries, always take them out before putting the MSX in storage, even when they’re not empty yet.

Lithium batteries are a good alternative for alkaline, in Europe e.g. Energizer and Varta sell Lithium AA batteries. These are marketed as “pro batteries” and more expensive, but since they are internally solid they do not leak and also last longer. (Note, Lithium batteries are not to be confused with rechargeable Li-Ion ones.)


Electrolytic capacitors have corrosive fluids inside which can leak. When leaked these corrosive fluids will eat through the board and damage it. Some manufacturers have used bad capacitor batches which are more susceptible to leaking than others.

Pay attention to these models:

When you see leakage underneath capacitors, or they are “bulging”, they must be replaced. Capacitors also should have “vents” etched into the top which can break to release pressure, capacitors without vent are best replaced as well.


The front plastic has become very brittle and breaks easily, so these should be packaged with extra care and protection when shipping.


When a connector’s connection is intermittent, causing flickering video and crackling audio, the connector likely has fractured solder joints. Often at first this only happens when the connector is wiggled around by the user, and gets worse over time to the point where it is difficult to get a good video or audio connection.

This issue can affect all MSX models, often the following connectors:

  • SCART, DIN and RCA A/V connectors
  • DE-9 Joystick port connectors

This occurs because as the connector is inserted repeatedly during normal use, insertion forces are applied to the solder joints which connect the socket to the board, and over time they can break, especially as the solder becomes brittle with age.

The repair is easy: simply resolder the solder joints. Apply a hot soldering iron to them and let the solder re-flow. Add a fresh bit of solder to make it more rigid.

Here is an example of what fractured solder joints look like:

Fractured solder joints on the DIN8 connector of a Yamaha YIS-503F.
Fractured solder joints on the DIN8 connector of a Yamaha YIS-503F.

You can see the fracture lines on the marked solder joints.

Sometimes the stress has also caused the solder pads to lift from the board. In this case you can see breaks in the connection between the pad and the trace connected to it. Also as you reflow the connection, you will notice that the pad is loose. In this case you will need to repair the connection with a little bodge wire between the pin and the other end of the trace.