Two to three weeks ago I got the unit from Deepspar. It has to be connected
to the PC power supply.

As I work in computer sales and repair over 21 years, I have seen a lot of PC
with defect power supplies, and because of lightning - shot mainboards and hard
disks. Two times I got a PC where just the case remained "working" ...

Therefore I surched for a protection for the 5V/12V power of a PC and didnt
find anything, neither through the internet nor from a local UPS specialist.

My question to the pros:
Is it a matter to think about and if yes, how and what can I do?
I do not believe in better quality of high priced power supplies - just with more
and longer cables - but dying within the same time frame. Its the dust, the smoke
and the fan ... (The pros here most probably know what one can find, opening a
customers PC case ....)

Thanks in advance

I've never found a commercial product like you've described. I've toyed with the idea of making my own add-on overvoltage protection, but never even got as far as making one. Really, a good brand of power supply will have built-in OVP. I've seen a few myself where everything except the case itself was destroyed, and they were always with some off-brand power supply. Deer is a brand famous for being absolute crap, and one of my total losses was a Deer. I made an inside joke a while ago something about a DEER in the headlights, but wasn't sure if anyone got it

Bottom line, in theory a real crowbar OVP would be best, but the protection a good PS offers is usually good enough. All power supplies can die, but what matters (At least to me) is that it doesn't take anything with it.

Hello,

I have one good solution for this!
Especially i am working on it.
It is almost ready, now in the beta state.

My device can catch aproximately 99% of bad power issues, and protect your hdd.
The price is low.

PM me if interested.

Regards,
Janos

Is this like a crowbar OVP circuit that plugs into a 5V/12V connector? Or something else?

I have seen some similar solution for shorting the over voltage, but all have worse quality/efficiency, because the PS are too strong.
The bad, malfunctioning PS can burn own wires inside the box, and outside (like 5V/12V) as well.

My solution is generally a fuse circuit with paranoid, double protection for overvoltage.
It is designed for protect the HDD exactly, and don't cares for the other components, because usually the data is the most important.

My protector can catch the spikes, the massive overvoltage, the reverse polarity (like short diode on the PS's secunder circiuts), the noise on the line, and on some cases can protect from lightning a well.

The product is in testing state now.

Regards,
Janos

I also have designed a full solid state, resettable and microsecond speed protector for single and drive array. I can switch to nanoseconds but don't know how to test it (generate nanosec spikes)