Zoom 9050 Fuse Issue

[Kirito]

Hi all,
I have ventured here to try and hopefully learn a thing or two as I am not too savvy with the inner workings of electronics, and I am having an issue with one of my effects processors that I enjoy using.

The effects processor is a Zoom 9050 that was manufactured in or around 1993. It has worked up until last week when I plugged it in, the screen flashed, and the unit went dead. I found some posts about the Zoom 9050 on the web, but they are few and far between being that the unit is quite old and out of date. However, I did find a post that specified one of the main problems users have had with this unit, and that is a fuse that is found on the display circuit board tends to go out on these units. I disassembled my processor and I have found where this fuse is located. It is soldered directly to the display circuit board.

I am at a loss as to where to find a replacement fuse for this unit. The fuse is a black surface mounted type that has 0.4a printed on it (I figure it is a 400mA fuse, but I don't know the voltage requirement for the fuse). The fuse is approximately 3/16" to 1/4" long by 1/8" wide by 3/32" thick. There is the number 34 also on the fuse preceded by a symbol similar to an asterisk (looks like a Japanese symbol). I have scoured the web to try and find something similar to replace it, and I have located some that look somewhat similar, but not exactly the same. Most are half the physical size of the one I need to replace. In a post I discovered someone recommended replacing the fuse with a Slow Blow fuse as well.

I don't know if this information will help at all, but the power supply has the following noted on it:

Input AC120V 60Hz 20W
Output DC9V 1000mA

Well that is about all of the information that I have currently, other than I have owned the unit for about 14 years and have taken very good care of it (It still looks almost brand new). It has always been kept in a clean, dry area free of dirt and dust. I would very much like to get it functioning properly again. I enjoy using it to play through even though there are so many other newer effects units out there on the market today, and it does have some sentimental value to me also. Thank you for any help.

[Enzo]

Everything works until it doesn't. You probably had nothing to do with the failure, unless you plugged the wrong adaptor into it.

Did you test the fuse? I can see its solder pads from here, so no problem putting your ohm meter probes to it. Is the fuse open? I see no point looking for a fuse if the one you have is still good. Your unit has worked for 20 years, so I tend not to think in terms of "common failures". Anything that "usually goes wrong" would have already done so.

meanwhile, I'd agree it is probably a 400ma fuse. As to voltage rating? Hell the whole circuit runs on 9v, so voltage is never an issue. 125v or 250v would never matter, and if you could find a 32v one, it still wouldn't matter.

Size? Please measure the fuse in metric.


Here are three I found with a quick trip to Mouser. I chose the black one, but either will do.

https://www.mouser.com/Circuit-Prote...z0x6iaZ1ywpldt

My search route? Fuse...surface mount...in stock...400ma.

[Kirito]

Thank you for the reply Enzo.

I can guarantee that I did not plug the wrong adapter into the unit. I used the factory supplied power supply. I am very particular about that with my electronics.

I have taken out my multimeter and tested the fuse. I get no continuity reading, or any change in the reading of any sort. I tested it on other items on the circuit board and got readings on those parts, but not on the fuse. The fuse does not look like it has opened up, but it does look like burned or cooked/dried out charcoal on the sides.

The fuse is 6.4mm long x 3.2 mm wide x 2.4mm thick. Sorry, I should have included those in the original post.

Thank you for the link to the fuses. I had stumbled across that one as well in my search. Being that I am not very knowledgeable about electronics I wanted to make sure I was going about this correctly.

Once again, thank you for your reply and the information you provided. I very much appreciate it and I will order some fuses and at least be able to either fix the issue, or narrow down my trouble shooting.