Hey! so I've been trying to figure this issue out for a while now and have gone to quite a few different electronic shops with no one able to help me with a solution, so thought I would ask a forum!

Basically I got given a bass guitar amp head (Behringer BX300T), which was just missing the fuse out the back but apart from that apparently working fine and had never been opened up by the owner. The fuse holder looked like one I'd never seen, with 3 terminals and pushed close together (no space for a regular glass/ ceramic fuse).

I thought possibly it took a thin blade fuse like used in cars but I've never seen other devices use those types of fuses. Also thought possibly the pins have been pushed together in the past, but then I'm still not sure what the middle terminal would do unless it was some sort of 3 pin fuse? The middle fuse connecter was wired to the neutral of the power socket pin on the backside.

So I tried a regular fuse and it didn't fit, and was told it definitely wouldn't be a car type blade fuse. Wasn't sure if there was a holder tray that held it in place. Asked a guy in an electronics shop and he said he'd never seen one like it and it'd be easier just to replace the whole socket. The sockets they had have a regular two connector fuse holder. So I took the old socket out and found a different pin layout on the back of the two and got stuck as how to rewire it with the new socket.

This is the new socket back:

The wiring runs through to a switch and then to the unit.

With the original the live went from the socket, up through the switch, and then to the unit. And two other wires went through the fuse to the unit. The neutral to itself on the fuse? And the ground to the ground in the unit.

With the new socket, the live is forced to run through the fuse, so I assume that then runs up to the switch. Ground to the ground. But that leaves me stuck with the neutral and also the two wires coming from the unit that were running through the fuse previously.

It was hard to get in there and take clear photos so I've drawn it out as clearly as I can:

So basically need to either get this new socket wired in (as no one seems to recognise the original one), or get a fuse that fits the original (which no one seems to know what it is).

Let me know if this is confusingly written and I'll try to clarify, I am very novice to it all! Thanks for any help!!

 

Your mains switch will have a neon or led inside, that is the Third wire for the Neutral, i assume the Blue Red is Live in out.

 

Awesome cheers! So there is no light on the switch like most of these units, just a solid switch. I think the black wire is the live as that was attached to the live on the old socket, and runs up through the switch, so I have kept that the same. From the side of the transformer I think the red is the 240v wire, and the blue is 120v for a voltage swapping option with the old socket. So I have run the neutral up to the switch, and then to the red wire. I have then taped off the blue wire as I'm pretty sure it's just for 120v option and I just need the 240v.

It's still not turning on though, I am not sure if I have burnt out the fuse or if the unit has other issues, or my wiring is wrong...

Should I not run the neutral through the switch and just connect it directly to the red wire?

Cheers!!

 

I would run the Live through the switch and Neutral direct, get a Dvm ( multimeter) and measure the resistance of the transformer primary to see if it's ok, and measure the mains coming in at the socket. Check continuity from the socket to the transformer, see if the 230V is at the transformer primary, check secondary output.