Blown fuse in Amp Head

[Weststarx]

Hello chaps,

The fuse in my Laney RB9 amp head blew today at rehearsal just as I started getting warmed up.

I've never had a fuse blow before in an amp, is there anything I should be worried about?

I didn't have any fuse replacement on me and had to use an Fender RUMBLE 350 from the studio for the rest of the practice (which was absolutely awesome btw)

Thanks

[flyfisher]

I wouldn't worry about it. Just replace it with the same type of fuse.

If it quickly blows again, [u]then[/u] I'd start to worry about it.

[Dad3353]

Fuses can age, and 'blow' for no apparent reason. They should, in the first instance, be replaced with a new fuse of the same type and rating. If this replacement fuse also 'blows', however, there is in all probability a more serious fault in the amp which will need the attention of a competent technician.
Hope this helps.

[Weststarx]

Thanks for the advice guys,

I'll source a new fuse and see what happens...


The amps only a few months old!

Edited June 14, 2014 by Weststarx

[Weststarx]

Well its blow two more fuses...time to take it to the shop!

(Just hope they don't fob me off with an excuse)

[flyfisher]

OK, so now we know there is something to worry about.

When you take it back to the shop be sure to tell them it has blown three fuses in quick succession. That points to a 'real' fault somewhere, so it would be bad form for them to try fobbing you off.

How quickly does the fuse blow after switching on? Immediately or after some time? There could be some clues there so be sure to give the shop as much info as possible.

Good luck with getting it fixed.

[Dad3353]

[quote name='Weststarx' timestamp='1402564941' post='2474775']...The amps only a few months old![/quote]

Here's where you find out if the good reputation of the supplier is justified..! It's surely under guarantee..? Either they fix the fault rapidly or they replace with a new item, I would suggest. No big deal if they're up to scratch. Stuff happens, and a good supplier will sort it out.
Let us know how things develop, please..?

[Weststarx]

[quote name='flyfisher' timestamp='1402694407' post='2476139']


How quickly does the fuse blow after switching on? Immediately or after some time? There could be some clues there so be sure to give the shop as much info as possible.

[/quote]

Immediately! Soon as you turn it on it blows a fuse again.

They did say when I brought it if I had any problems they would send it back to Laney, my biggest concern is I cant find my receipt they have all my details on the computer system so I presume they have a list of the stuff I've brought from them on there.

I'm going straight in tomorrow and will report back how I get on

[icastle]

Last ditch attempt at a simple solution...
This fuse you replaced - are you sure you replaced it with the exact same type?

From what I can see, the original fuse was labelled [b]T[/b]2A - if you replaced it with an [b]F[/b]2A then it'll blow immediately.

[Weststarx]

[quote name='icastle' timestamp='1402697742' post='2476202']
Last ditch attempt at a simple solution...
This fuse you replaced - are you sure you replaced it with the exact same type?

From what I can see, the original fuse was labelled [b]T[/b]2A - if you replaced it with an [b]F[/b]2A then it'll blow immediately.
[/quote]

The fuses I brought are labled F5A.... Maybe that's it then!

I brought these other fuses from another music retailer and actually gave him the original fuse so I would get the same ones - but obviously not...

Maybe I will buy some T2A fuses then and see if that solves the problem, I will take it in anyway and plug it in at the music shop and see what happens.

Would somewhere like Maplins do them?

[icastle]

Ah.

Well looking at the RB9 manual it specifies a T2A.

'T' fuses are designed to allow a power surge as the unit switches on ('T' stands for Time Delay).
'F' fuses are designed to blow as soon as their power rating is exceeded ('F' stands for Fast blow).

You 'might' get away with using an F5A instead of a T2A, but it's a crude workaround and by no means certain to work.

I'd seriously put the right fuse in there before trying to pursue a warranty repair.

Yes, Maplin do them - I'm presuming they're about 20mm long?
http://www.maplin.co.uk/p/2a-time-delay-glass-20mm-fuse-10-pack-gl62s

[Bloodaxe]

[quote name='Weststarx' timestamp='1402698843' post='2476218']
The fuses I brought are labled F5A.... Maybe that's it then!

I brought these other fuses from another music retailer and actually gave him the original fuse so I would get the same ones - but obviously not...

Maybe I will buy some T2A fuses then and see if that solves the problem, I will take it in anyway and plug it in at the music shop and see what happens.

Would somewhere like Maplins do them?
[/quote]

Yes, but you'll have to buy a pack of 10:— http://www.maplin.co.uk/p/2a-time-delay-glass-20mm-fuse-10-pack-gl62s
If you have a TV repair shop anywhere near you, that could be a good call.

Also... check that yours is 20mm long & not the older 1.25" version.

The 'T' stands for 'Time Delay', but they're often called Slow-Blow fuses. They're designed to withstand the current surge that occurs when you switch the amp on & the power supply capacitors charge up, but with repeated use they eventually fail (exactly like a proper light bulb).

If the amp blows several Ts on start-up, it means there's a problem.

[Dad3353]

[quote name='Weststarx' timestamp='1402698843' post='2476218']
The fuses I brought are labled F5A.... Maybe that's it then!

I brought these other fuses from another music retailer and actually gave him the original fuse so I would get the same ones - but obviously not...

Maybe I will buy some T2A fuses then and see if that solves the problem, I will take it in anyway and plug it in at the music shop and see what happens.

Would somewhere like Maplins do them?
[/quote]

May I respectfully suggest that you put the original fuse back in, touch nothing else and take it back to the shop that supplied it..? It does seems as if you don't know what you're doing, and nor do the other 'music retailer' that sold you the fuses. All you can do from here is muddy the waters, and perhaps expensive damage. It's under warranty; take it back. By all means learn more about all this stuff; it's in your interests to do so, but get this amp up and running first. No more 'second guessing'.
Hope this helps.

[Weststarx]

Took it back into the shop today and are sending it back to Laney next week.

Pleased its off to be looked at by Laney and not some randomer with a screwdriver as well.

Will let you guys know what the problem was when I find out!

[Weststarx]

Its coming upto 3 weeks since my amps been sent back to Laney, how long does it normally take to be returned?

Or shall I pester them a bit more?

[flyfisher]

No idea really, but I'd expect them to be able to give you an estimated time almost immediately. I'd have pestered them for an estimated return date after a few days.

And don't let the shop fob you off. Your 'contract' is with the shop and it's [u]their[/u] responsibility to fix what they sold you. Sure, they might get Laney to do the repairs, which is fair enough, but it's still the shop's responsibility to make it happen to your satisfaction. It's the shop that should be chasing Laney so that they can keep their customer (i.e. you) happy. Three weeks with no explanation about what's going on doesn't seem like great customer service to me.