Problem with failing Zip drive
Some models of Iomega Zip disk drives had high failure rates. Originally, Zip drives were made in USA. As Zip grew in popularity, production was largely moved to Malaysia, and it is possible that quality declined in a tradoff for increased production. The most common failure of Zip drives is known as the "click of death", where the drive no longer recognises disks. A less common failure is where the drive can no longer eject a disk.
click of death
A Zip drive may develop the "click of death" after a life of heavy use. Unaffected by software commands, the drive will retract and re-engage the heads a few times, unable to recognise the media. The cycle of moving the heads over and then away from the platter makes a "click" sound. After a couple failed attempts to recognise the media, the heads retract. A drive affected with this problem has permanently failed.
unable to eject
It is possible for a Zip drive to stop ejecting disks. After pressing the eject button or using a software eject command, the drive tries to eject a disk. Listening very carefully, one can hear the mechanism try five times to eject. After the failed attempts to eject a disk, the drive activity enters a state of slow steady blinking. To retrieve a disk, you must power-off and use the emergency eject hole. According to Iomega documentation: "a slow steady blink may indicate a problem with the drive".