My Passport Ultra not mounting on MAC

Hi, I bought the HD 5 months ago and used it to store my files. Now I need to use it at work and it worked fine for a while then stopped mounting intermittently until eventually I get nothing - won’t mount at all. Took it home and it mounted (after about 40 tries) so I resued data and re-initialised the disc. Now nothing - can’t even see it in disc utilities. I have most up to date OS and the device has been treated well. I tried updating Passport firmware - just get a ‘no disc found’ message. The light flickers and drive makes all the right noises when attached to any mac computer - but nothing shows on Desktop. Help please!

Try a different cable.

If the drive still does not mount you will need to consider replacing the unit.