Obsolescence guides · MELSEC FX series catalogue
MELSEC FX1 and FX2 obsolescence
Mitsubishi MELSEC FX series · 1990–present, partly discontinued
Where the platform stands
The FX1 and FX2 generations are discontinued. FX3 is itself now transitioning, with FX5 as the current range.
Why spares are hard to find
FX is fitted to a vast number of Japanese-built and OEM machines across Europe. As with MicroLogix, the machine outlives the controller and the machine builder has often moved on.
What actually fails first
From what comes through a repair bench on control gear of this age. Worth reading before you buy a replacement — two of these are cheap fixes that get misdiagnosed as a failed module.
Processors of this era keep the program and retentive data in volatile memory backed by a lithium cell. The cell lasts years, not decades — and when it dies the program goes with it on the next power cycle. Many "dead processor" calls are a flat battery and a lost program. Keep a current backup of the program off the machine; it is the cheapest insurance in the panel.
Relay outputs are rated in operations, not years. A contact switching an inductive load every few seconds reaches end of life long before the rest of the module. Symptoms are intermittent: the output is commanded and the device sometimes does not move.
The migration route, and what it really costs
FX5 with GX Works3. FX programs largely transfer, which makes this one of the gentler migrations — but the terminal layout and extension modules differ, so the panel work is real even when the program is not.
The case for keeping it running
Substitutions we would consider within the family
Each of these has conditions attached — read them. None is a blind swap, and we do not offer substitutions for safety-related functions at all.
| FX3U-16MR/ES-A | FX3U-32MR/ES-A — fits and runs with no changes |
|---|---|
| FX3U-32MR/ES-A | FX3U-48MR/ES-A — fits and runs with no changes |
Spares worth holding
If you are keeping the platform running, these are the items whose failure stops production — hold them rather than waiting to need them.
All 26 MELSEC FX series parts we source →
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Forge Horizons is an independent sourcing merchant and not an authorised distributor or agent of Mitsubishi. This page is general guidance from our own sourcing experience, not engineering advice — confirm anything safety-related with the manufacturer or your integrator.