I have this actually USB iomega eGo 250GB hard drive which seems to have some defects.
I took it out from its box and installed it in a Dell XPS M1330 laptop as primary hard drive. I used MHDD V4.6 to check it but it does not detect it. When I try to have informations with the command ID it says "drive not ready".
I also tried MHDD V4.5, this one seems to detect it but it does not appear (though neither in V4.6) in the device list when Shift+F3 are pressed. But it reports the following message "Warning: this drive is locked by ATA password" while I have never set any password in this drive. When I want to scan it I get the following message: "Drive has been disconnected"
I searched in previous posts and have not found any relevant information.

Try on another desktop PC.

If the drive is seen correctly and can access LBA (i.e. scan) the enclosure has problems.

If you can't access LBA or the drive appear to be locked or have blended problems, there's nothing you can do except seeking professional help (it's an internal failure).

If the drive has developed bad sector / zone , the only thing to do is seek pro help for refurbishing (it's a thing I do) if you want to fix it safely (again, no DIY).

Otherwise, replace the drive.

Is there something doing as much as mhdd that supports more hardware versions?

MHDD supports only some SATA controllers in (now common) AHCI mode; for other controllers you need to use select the SATA controller mode called IDE / compatibility / legacy mode (depending on what terminology your BIOS uses). If your laptop BIOS has that option, then try that selection. If your laptop BIOS does not have that option, then try a desktop PC (as BlackST suggested) since they are more likely to have the necessary BIOS option.

An alternative utility you can investigate, is HDAT2.