You are here

what fuse do I need, yamaha emx66m

For performing musicians and engineers: stagecraft, engineering and gear.

what fuse do I need, yamaha emx66m

Postby ciarancussen » Mon Oct 19, 2020 11:43 pm

I'm confused on what fuse i need for my mixer. It says F1Al 250V on the blown fuse (took out in photo). any help appreciated... https://drive.google.com/file/d/1oC0x5L ... sp=sharing
ciarancussen
New here
Posts: 4
Joined: Mon Oct 19, 2020 9:53 pm

Re: what fuse do I need, yamaha emx66m

Postby Mike Stranks » Tue Oct 20, 2020 8:47 am

Welcome! :thumbup:

The 'blacked-out' info on the circuit board is stating a 1.2 amp 250 volt fuse. But why it's blacked-out I'm not sure...

Do you know why the fuse blew?
Mike Stranks
Jedi Poster
Posts: 7652
Joined: Fri Jan 03, 2003 1:00 am

Re: what fuse do I need, yamaha emx66m

Postby Tomás Mulcahy » Tue Oct 20, 2020 9:40 am

Are you in the UK or US? Is the unit the 110V or 250V model?
User avatar
Tomás Mulcahy
Frequent Poster
Posts: 1810
Joined: Wed Apr 25, 2001 12:00 am
Location: Cork, Ireland.

Re: what fuse do I need, yamaha emx66m

Postby Hugh Robjohns » Tue Oct 20, 2020 9:44 am

ciarancussen wrote:I'm confused on what fuse i need for my mixer. It says F1Al 250V on the blown fuse (took out in photo). any help appreciated...

The general rule is you replace like for like... An F1A fuse is a 1 amp quick-blow (fast) fuse. Given Mike's detective work, it looks like you could possibly increase that to F 1.25A.

The question is, why did it blow? Fuses can just spontaneously die through old age or vibrational fatigue in mobile gear... but usually they blow because of a fault.
User avatar
Hugh Robjohns
Moderator
Posts: 29029
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Re: what fuse do I need, yamaha emx66m

Postby ciarancussen » Tue Oct 20, 2020 11:03 am

It’s a 250v version. Not sure why the fuse blew as I got the mixer with some speakers second hand.
ciarancussen
New here
Posts: 4
Joined: Mon Oct 19, 2020 9:53 pm

Re: what fuse do I need, yamaha emx66m

Postby Hugh Robjohns » Tue Oct 20, 2020 12:02 pm

Had it been working normally for extended periods without issue before the fuse went? Any indication of a problem -- smoke, nasty noises, high temperatures -- before it blew?
User avatar
Hugh Robjohns
Moderator
Posts: 29029
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Re: what fuse do I need, yamaha emx66m

Postby BJG145 » Tue Oct 20, 2020 5:06 pm

Mike Stranks wrote:The 'blacked-out' info on the circuit board is stating a 1.2 amp 250 volt fuse. But why it's blacked-out I'm not sure.

That's really weird. That's bugging me now.

Image

^^^

What they say. Stick in another one and cross your fingers.
User avatar
BJG145
Jedi Poster
Posts: 4675
Joined: Sat Aug 06, 2005 12:00 am

Re: what fuse do I need, yamaha emx66m

Postby wireman » Tue Oct 20, 2020 5:10 pm

BJG145 wrote:
Mike Stranks wrote:The 'blacked-out' info on the circuit board is stating a 1.2 amp 250 volt fuse. But why it's blacked-out I'm not sure.

That's really weird. That's bugging me now.


I assumed that only one was supposed to be blacked out based on supply voltage.
wireman
Frequent Poster
Posts: 559
Joined: Fri Dec 17, 2004 1:00 am

Re: what fuse do I need, yamaha emx66m

Postby BJG145 » Tue Oct 20, 2020 5:12 pm

Ingenious. I'll buy that. They started redacting and got carried away,
User avatar
BJG145
Jedi Poster
Posts: 4675
Joined: Sat Aug 06, 2005 12:00 am

Re: what fuse do I need, yamaha emx66m

Postby BJG145 » Tue Oct 20, 2020 5:23 pm

...now, I don't know anything about fuses. But one thing they didn't scribble out is: "T4A". As far as I can see from a bit of Googling, this is "slow-blow", but the one you took out is "F1A" which is "fast-blow".

The game's afoot.

Image
User avatar
BJG145
Jedi Poster
Posts: 4675
Joined: Sat Aug 06, 2005 12:00 am

Re: what fuse do I need, yamaha emx66m

Postby Mike Stranks » Tue Oct 20, 2020 6:19 pm

Dr Watson here...

This is the relevant bit of the service manual:

Image

Full manual available at: https://drive.google.com/file/d/1xnYSPSF7Tm1iYmctkVIgHUGtl_Ljj7b1/view?usp=sharing
Mike Stranks
Jedi Poster
Posts: 7652
Joined: Fri Jan 03, 2003 1:00 am

Re: what fuse do I need, yamaha emx66m

Postby AlecSp » Tue Oct 20, 2020 7:41 pm

Tranceformer - magic!
AlecSp
Regular
Posts: 476
Joined: Tue Nov 16, 2004 1:00 am

Re: what fuse do I need, yamaha emx66m

Postby BJG145 » Tue Oct 20, 2020 7:50 pm

Mike Stranks wrote:Dr Watson here

...except...

Image

You know my method. It is founded upon the observation of trifles.
User avatar
BJG145
Jedi Poster
Posts: 4675
Joined: Sat Aug 06, 2005 12:00 am

Re: what fuse do I need, yamaha emx66m

Postby BJG145 » Tue Oct 20, 2020 8:18 pm

Looking back to an earlier page of the service manual, there's this:

Image

What is all this J and U stuff...? Are these descriptions for the fuse in different versions of the circuit board...? It's not very clear. But it seems quite plausible that the one you removed blew because it's the wrong type.
User avatar
BJG145
Jedi Poster
Posts: 4675
Joined: Sat Aug 06, 2005 12:00 am

Re: what fuse do I need, yamaha emx66m

Postby Hugh Robjohns » Tue Oct 20, 2020 9:57 pm

BJG145 wrote:Looking back to an earlier page of the service manual, there's this:

It's quite likely the same raw PCB is used in multiple designs with different ratings. Hence the crossed out options.

But it seems quite plausible that the one you removed blew because it's the wrong type.

Hence my earlier question: Had it been working normally for extended periods without issue before the fuse went?

And: Any indication of a problem -- smoke, nasty noises, high temperatures -- before it blew?

If it had been working normally before hand, the removed fuse was probably the right value (or close to it). Ditto if the unit developed an obvious fault immediately prior to it popping.

But reading the specs for that unit, with such a large inrush current, I was surprised it was an F (fast-blow) fuse... I would have expected a T (anti-surge) fuse.
User avatar
Hugh Robjohns
Moderator
Posts: 29029
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Next