A computer based on ASRock AM2-NFG6 VSTA mobo and 1.5 TB Barracuda Seagate SATAII HDD and 8 GB RAM has presented some disk failures and that is the issue I want to solve.

Some years ago the computer would not start.
Te HDD couldn't be read. And as I took another similar machine and worked with it.

Two months ago I started revitalizing it by purchasing a brand new 1 TB, 7200 rpm Barracuda Seagate disk, installed it and attempted to setup Fedora 32 because, to my surprise, the new disk failed.
Claimed guarantee and got a replacement.

I thought to give it a try to the 1.5 TB disk.
Started Fedora 32 from the setup disk and ran a write-to-zero process and badblocks reported 0 errors.

I then installed Fedora 32 on it.
Video was working erratically and I found out how and was able to install the Nvidia drivers.
The computer worked fine…
until last Monday.

ASRock started a constant single beep.
A slight click could be heard, presumably from the HDD and the machine started to work very slow.
Tried to find out temperature but it wouldn't allow me and it finally shut down.

I then replaced 1.5 TB with new 1 TB disk.
And did all the setup process again.

To my surprise I was not able to finish properly.
Once Fedora 32 started I was not able to go install the NVIDIA drivers on newly setup ASRock.
HDD started a very slight click too.

I installed both disks on the ASUS machine to perform some tests.
1.5 TB disk reported 32 errors after running badblocks.
A write-to-zero process was run on both disks.
1 TB is being run.
1.5 TB showe I/O error so I proceeded with wipe.

Meanwhile I tested ASRock PSU.
Yellow cables show a 11.3 V output.
The other cables show 5.12 and 3.09 V.
A new Thermaltake PSU I have as backup shows 12.7 V output.

¿Can the PSU be causing the HDD’s errors?

Typically the tolerance is +/- 5% and both the 3.3 and 12 volt lines are low are these open voltage readings or under a load. It is possible that low voltage might damage a component. It also matters how clean i.e ripples are on the line too. I would be reluctant to use the PSU.

2 members found this post helpful.

Thank you very much, @michaelk.
No load. I took the PSU out of the cabinet.

I will set the new one I have stored.
500 W Thermaltake with no 80 Plus certification.

Agree with michaelk - that's out of spec and probably indicative of some internal failure (iirc ripple in ATX spec is 50 mV, FWIW; modern quality/high efficiency units usually are better than 1% though). Try a new/known-working unit and see what shakes out there. It is possible for a bad/failing PSU to damage hardware it is connected to, but in my experience its more likely the system will just be unstable/behave oddly until the PSU is swapped (note 'more likely' is not 'all the time').

Purchased two new Thermaltake PSUs.
A 600 and a 500 W.
Problem solved.
PSUs had worked a lot in 12 years.

Thank you very much.