My WD400BB hdd makes clinking noises. MHDD reports it does not support LBA (?), what could be wrong?

Usually 1% - it is PCB problem, and 99% - HDA problem, dead head etc. You can try swap PCB from identical good HDD (strongly identical, with same capacity and MDL string on label!), to check your luck.
If your drive is in 99% - your files may be recovered by professional data recovery service only, and drive repair is not possible.