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How to replace a fuse for AI Contra 310 BA?

Ian Jesse

Ian Jesse

Jan 2, 2009
9
0
New York, NY
#1
I went to turn on the amp that I've been using about 13 years and the light won't turn on. I can't get any power and assume the fuse has been blown. I can't seem to find it or anything online showing where it is. Has anyone ever had to replace a fuse on the Acoustic Image contra 310 combo amp before?
 
#2
If it's an internal fuse, it's NOT user replaceable because it's part of the safety system and if you replace it and the fault remains there is the possibility of injury. A qualified service tech will use protection whenever replacing an internal fuse and/or use a current limited supply to limit the hazard.
 
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#3
agedhorse said:
If it's an internal fuse, it's NOT user replaceable because it's part of the safety system and if you replace it and the fault remains there is the possibility of injury. A qualified service tech will use protection whenever replacing an internal fuse and/or use a current limited supply to limit the hazard.
Click to expand...
Hmm...how can I tell if it's an internal fuse? I've taken the lid off and looked around, but don't see any fuses visible.

BTW do you know of any good amp techs in NYC? They're hard to find here.
 
#6
AI 310BA rear.jpg
 
#10
abarson said:
Does the back of your Contra look like the one in this link? It shows an external fuse holder.
https://www.talkbass.com/threads/ac...eries-ii-worth-it-used.1489226/#post-24631774

I'd still send it to a technician, as a fuse usually blows when there is some other fault and blowing limits the scope of the damage or hazard.
Click to expand...


It looks exactly like the one pictured in the DannyW reply. I haven’t found a fuse compartment in the 300 series.

The green light doesn’t come on. Nothing major happened like dropping it or spilling beer on it. It was at home working one day and then not turning on the next. I tested the power cord and it works fine with another amp. I’m assuming it’s the fuse which makes me wonder what type of fuse it is and how to replace it. I read that it takes a 6.3 slow blow fuse, but can’t seem to find any obvious fuses anywhere inside the amp.
 

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#12
You absolutely need to take it to a tech.
Reason: the external fuse holder is very apparent to anyone who should be replacing a fuse, and it’s also apparent that the required fuse is 3A slo-blo.
If these facts aren’t jumping out at you, you have no business playing with dangerous equipment. Save yourself the burning smells and scorched flesh and take it to someone who can check it out safely.
 
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#13
Ian,

The fuse should be in the small drawer-like plastic part right under where you connect the power chord. You will need to pull that part out using a straight-tip tool like a screw driver. I am sure there are tons of videos on YouTube that shows how you can do it without damaging/scratching the part. At the end of the day, it is a user-serviceable/changeable part (not like those parts you have to take the lid off to reach).

As some other posters mentioned, this might be due to another serious problem, so a qualified technician would be the safest bet; yet fuses have blown on me for no apparent reason and when I replaced them with a fuse with the original specs, the problem went away almost always. That is why the fuse is reachable by any user. Otherwise, it would have been inside the hood.

Good luck…
 
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#14
Tesekuller Alper!

I found the fuses underneath the power input. Both seem fine. I switched them out and the amp still won't turn on :(

Sigh...I need this amp and have not found anyone in the city that I can trust to take amps to. There was a good guy in BK that moved away years ago. I went to some hack off Google who did nothing.
 
#16
Ian Jesse said:
Hmm...how can I tell if it's an internal fuse? I've taken the lid off and looked around, but don't see any fuses visible.

BTW do you know of any good amp techs in NYC? They're hard to find here.
Click to expand...

Fuchs audio in new jersey is probably the most qualified shop in the country to service these amps. I highly recommend them. andy is a user here, as well.
 
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#18
Ian Jesse said:
Tesekuller Alper!

I found the fuses underneath the power input. Both seem fine. I switched them out and the amp still won't turn on :(

Sigh...I need this amp and have not found anyone in the city that I can trust to take amps to. There was a good guy in BK that moved away years ago. I went to some hack off Google who did nothing.
Click to expand...
FWIW, on that style of fuse holder the 2nd fuse (closest to the outside of the drawer) is usually (always?) a spare, not in the circuit,
but yeah, this sounds like a job for a qualified repair person.
 
#19
newfuture said:
FWIW, on that style of fuse holder the 2nd fuse (closest to the outside of the drawer) is usually (always?) a spare, not in the circuit,
but yeah, this sounds like a job for a qualified repair person.
Click to expand...
It may also be a different value for 240V use rather than 120V use. Beware.
 

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