IR receiver punking out on my XBR

[fifties]

Gentlemen, thx a ton. Tom.J and Findm, this is exactly the information I need.
If the sensor has gone bad, where would I find a replacement, would you know of a source?

AFA the IR window, I used a glass cleaner to make sure that it wasn't obstructed.
The TV is in a darkened room, and nothing has changed AFA lighting in a dozen years.