Possible components: High-voltage MOSFET, IGBT, thyristor, or diode. Let's consider a high-voltage diode. If it's a diode, maybe a Zener or a high-voltage rectifier. For example, the 1N5346 is a Zener diode, but that doesn't match.
Alternatively, an IGBT might have a part number pattern like "FGA" series from Fuji Electric. But the "hv490fhb-n80" doesn't fit that pattern. Maybe an optocoupler with high-voltage isolation. hv490fhb-n80 datasheet
Another possibility is a high-voltage transistor, such as a BJT. Companies like Fairchild (now ON Semiconductor) have parts like the 2N3904, but high-voltage models might be something else. For example, the 1N5346 is a Zener diode,
First, I should try to find the datasheet online. Let me do a quick search for "hv490fhb-n80 datasheet". Hmm, the results aren't showing up. Maybe the part doesn't exist under that exact naming, or it's a non-standard part. Perhaps it's a typo or a custom part. Alternatively, maybe it's from a less-known manufacturer or a newer component not widely indexed. Maybe an optocoupler with high-voltage isolation