Super Famicom keeps blowing fuse

[mmmonkey]

I've recently bought a Super Famicom, and I've been using a MD1 psu with it.

I took it apart to clean it, and noticed that the lockout chip was disabled in an odd way, so i thought I'd undo the mod. That was fine, put it together (although i didn't screw it together), tested it and all wasy okay.

Then the fuse blew. I replaced it and checked for any obvious signs of me buggering it up, it all looked okay, then the fuse blew.

I always switch it on after unplugging it to discharge it, I replaced the fuse again, and it worked, then it blew again. I then noticed that the fuse only blew if i plugged in the psu whilst the SFC power switch was in the On position.

Any ideas? It's not too bad as long as I remember what not to do.

I have been using 1a picofuse, I know that the original is 1.5a. I know a 1a one will blow easier, but would just plugging it in whilst it's switch on blow it?

Ta
Pete

[Papercut]

I reckon the problem would be the wrong fuse rating. I bet the machine sucks a lot of juice when you turn it on.

[mmmonkey]

I was hoping someone was going to say that. The shop I usually get the fuses from doesn't have the 1.5a, so it's either 1a or 2a. Would 2a cause me other problems, maybe damage something else, or should i look for an alternative supplier?

Ta
Pete

[Papercut]

well, if there _is_ a fault a 2A fuse might allow another component to become damaged.

you should find another supplier.

[mmmonkey]

thanks again

pete

[MD]

I would also suggest you try another PSU too, if the PSU is slightly damaged it might be outputing a higher voltage then it should be doing. The SFC requires a 9V at 800ma supply (slightly higher ma rating will be fine).

If you have a multimeter then test the voltage it should be around 10 to 11V with a load.

[mmmonkey]

Cheers MD, I'll check it out.

Pete

[mmmonkey]

MD - do you mean 9V with a load, and 10 to 11V without a load (excuse my stupidity). My MD PSU is just over 12V without a load, so this could be too much? Anyway, it's about time I bought a multi power adaptor with changeable plugs etc.

Any does anybody know where to buy picofuses? I'm having trouble finding them anywhere.

Ta
Pete

[Papercut]

You got the load / without load stuff right - thats what happens with unregulated mains adaptors

I don't think 12v unloaded is really a problem - is this what you're using on the SFC?

The Super Famicom psu is actually rated at a slightly unusual 10v DC 850mA (with 2.1 mm DC jack, neg tip).

Not sure about the fuses - try looking at rapid electronics' website:

http://www.rapidelectronics.co.uk/

[mmmonkey]

yep, it was the 12v without a load psu i was using. Thanks for the link, they do sell the correct fuse

Thanks for the help people, and your patience!

Pete

[randombs]

hey it's almost nothing to do with this, but i was looking at uk snes/nes psu's at work and they're rated at 9v AC (or 10v i can't remember). i thought this was a printing mistake but using the multimeter, i wouldn't get a reading in DC mode, but would get a reading in AC mode. odd, i've never seen anything like it before.

i'm assuming you couldn't use a uk snes psu with a jap/us machine then? (i heard the us machine has a different connector i think. apparently it works on the virtual boy and our virtual boy at work has an odd socket for power. no psu though)

[Papercut]

Thats right, UK snes's use 9v AC like the pal nes, which is totally different to the ntsc machines' 10v dc.

on top of that the dc jack is different between the jpn sfc and us snes.

[mmmonkey]

Just to let you know, it was caused by the wrong fuse, i pinched one from a PAL SNES and it's hunky dorey

Ta
Pete

[Papercut]

word

[zipper]

Very old thread, but I thought it worth resurrecting to add my 2p worth after finding it in a search.

Rather than hunt around for a single 1.5amp pcb / picofuse, you could always use an electricians trick... If you have some multi-strand wire, strip it back and take a single strand as fuse wire - this will likely be rated at a couple of amps and will blow as needed.

Use the info at your own risk! But seeing as you can pick up a snes for about the same as amount as a pack of fuses, it makes good economic sense :-P