iMac 2007 not boot

[LittlePaul]

Hi,
my iMac 2007 lost bootable hd.
I have change the hd but with the new is the same.
It work for a month, more or less, until it lost the hd like a bootable disk.
It start only in Recovery mode.
in Recovery mode i can see the hd but it isn't bootable disk.

I have reset the PRAM too and nothing.

I can only reinstall Osx and it work until stop again.
How can i fix it?

Thank's

 

[FlorisVN]

what is the smart status of the HDD ?
It could be the HDD is about to die...

 

[nambuccaheadsau]

Maybe a terminal problem as it is coming up to twelve years old ~ dinosaur age in computers.

 

[LittlePaul]

I have another identical iMac that work perfectly.
This dinosaur wants to rest in peace!