Fuse for Neumann NSMa-23 Power Supply

[skaren]

Hi there,

I'm looking for some help figuring out what fuse I need for my NSMa-23 power supply for a Neumann SM69 Fet.

The burnt fuse (20mm) has the following written on it:

M 0.08/250C FN1

In the UK fuses tend to be either T for time delay or F for fast. My guess is that the M stands for medium.

I ordered T80MA AL250V fuses but these don't seem to work. I don't know if there is anything else wrong with the power supply.

Any advice on what fuse should be used would be appreciated!

Big thanks

 

[Khron]

"Don't seem to work" is a bit vague. Is that saying, they blow straight away?

Might not be a bad idea to power that through a series (tungsten fillament) lighbulb, a so-called "bulb tester".

Then again, if it's all stock, it wouldn't be too far-fetched to think one or more filter capacitors might've failed short-circuit, and as such, are drawing more current than normally expected, through the transformer.

 

[Whoops]

My guess would be that 0.08 means 80mA.

I would use a T (slow fuse) and not a fast one.

I uploaded the schematic to the technical docs section, see if that helps:

https://groupdiy.com/index.php?topic=44805.80

 

[skaren]

Thank you very much for the reply

 

[skaren]

"Don't seem to work" is a bit vague. Is that saying, they blow straight away?

Might not be a bad idea to power that through a series (tungsten fillament) lighbulb, a so-called "bulb tester".

Then again, if it's all stock, it wouldn't be too far-fetched to think one or more filter capacitors might've failed short-circuit, and as such, are drawing more current than normally expected, through the transformer.

Thanks for you reply. Yes, I was indeed a bit vague. The fuses don't blow and the unit doesn't power up.
I guess that seems to mean something else is wrong, maybe what you suggest.

That being beyond my pay grade I'll give to to a pro to fix.

Thanks again

 

[Whoops]

The fuses don't blow and the unit doesn't power up.

Well if that happens it means that the power is interrupted somewhere.
Or the Fuse is bad (I had bad fuses from factory before), or the Fuse was fitted incorrectly, or you have another problem or before or after the fuse.

Using the Multimeter in Continuity mode will be provide a clear picture of whats going on