What type of component is this??

[Murdock]

Title says it all.
This was in my 24V Monitora PSU and disconnected the negative rail (after the diode bridge) and the 0V rail from the rest of the PCB... after removing and replacing it with a link, the PSU now works...
So, can anybody tell me, what type of component that is? And why it was there? Is it a fuse?
Only markings are "W", "5" and  "A". Checked for resistance and got no readings with my DMM...

 

[Murdock]

Seems to be a Picofuse, right? Rated at 5A?

 

[PRR]

> Checked for resistance and got no readings with my DMM...
> Seems to be a Picofuse

If "no reading" really means "overload (too many Ohms)", then it isn't a fuse any more.

Why did it blow? That usually means other trouble.

 

[Murdock]

> Checked for resistance and got no readings with my DMM...
> Seems to be a Picofuse

If "no reading" really means "overload (too many Ohms)", then it isn't a fuse any more.

Why did it blow? That usually means other trouble.

Yeah, if it is a fuse, it is blown... Why it has blown, I don't know. It was like that when I bought the unit.
I will buy another fuse with 5A rating and try it for a few hours.