Mysterious part in an old calculator

Seems to be a 4.7 Ohms resistor.

As a totally wild guess, I would've said a polyfuse - but not if its ACROSS the supply pins.

Its probably semiconductor based, maybe a clamp protection diode - but they usually don't look that different to ordinary ones.

If it is semiconductor - its probably designed to sacrifice itself to save the chip.

Everybody should learn how to read a schematic !

This component is in series with the power supply, so it probably is a protection resistor (low value).

Thanks to all who responded. The device is indeed connected across (i.e. in parallel to) the power supply pins, so it cannot likely be a low ohm resistor or a fuse. It appears to be a tantalum capacitor. The measured capacitance is about 4.75uF. Photo taken after removing excess solder with wick:

It occupies the right footprint for an early smd tantalum and has a suitable part number (odd to see that on silkscreen) but I've never seen this particular construction.

The presence of tack-soldered radial tantalums elsewhere in the assembly made this an unlikely guess...

If guessing was requested, I'd have suggested an early TVS type for smd applications. Possibly part of an external wallwart protection scheme. This would have a similar part numbering system and footprint.

RL