That's the only physical failure in 20 years on radar equipped aircraft. Glad I had this on clear morning rather than flying around the equator at night.
I had a nasty one circa 1980 while flying a 737-200 Taipei to Guam at night. A Typhoon (the weather, not the aeroplane) was forecast to be on our direct track or thereabouts. The radar was a Bendix monochrome display with 180 miles max range. We switched the scale from 180 to 80 quite frequently and played with the tilt hoping to pick up the tall CB usually surrounding the eye of the typhoon. We even looked through the windscreen although we were in cloud.
The radar showed lots of what we interpreted as sea returns expected with large waves. No evidence of bad weather ahead after 1.5 hours in cruise in calm air in cloud. Where was the forecast typhoon? Without warning we hit savage turbulence and lots of lightning. The flashes illuminated Cb's in all directions. Clearly the radar had failed some time after we had left Taipei and we were over the West Pacific area.
There was no warning of the failure, and because the screen appeared "alive" with tiny echoes we took to be big waves, we trusted it. We turned 90 degrees from the planned track and picking our way between CB tops using lightning flashes, we were able to clear the immediate area and resume track to Guam.