Active Hub and Passive hub Fuse layout

[Penfold]

When testing I lost two fuses on my passive hub, but I figured that I might blow a fuse so I used the top four connections as if a fuse blew it would be easy to swap out.  My question is would it be possible to re-design the hub slightly to have a "Bank of fuses" to one side of the board instead of above each RJ45 breakout, so that way it would be easy to replace one if it blows.  There appears to be adequate space on the board to pull this off, but it would require a lot of trace re-routing.

This is probably a pipe dream, but I thought it would just lend itself to easier use of the hub.

Hmm... it retrospect you could always install the fuses on the underside of the board, but then again you run into problems when you are trying to re-solder as the connectors would get in the way.

Thoughts anyone?

 

[Corey872]

After blowing and replacing a few, it seems the easiest solution is to insert the fuses - at least the 'hard to get to' ones - to a level at or just below the top of the cat5 connector.  This way, they are easier to reach if (when?) they blow again.  It also doesn't hurt to limit the 'testing' to the top row of sockets if you can, as those fuses are a bit easier to get to.

[urthegman]

I made a tool for removing them by cutting a 6" section of wire hanger and making a small L-shape at the end of it. I then filed it down so it would fit beneath the fuse. It was either this or stealing the dentists instrument when he turned his back! LOL    Sometimes you may need to use a small flat headed screwdriver to push the fuse up a little from the bottom of the board and you might break a few fuses and have to pull them out with a needle nose pliers from the top while you heat the bottom. Finally, if the remaining solder clogs the pass through,  you might need to take a safety pin and bend it straight and press it at the top of the pass through while heating the bottom so that you get it all the way through the whole (this may require heating it 3 or 4 times to get it all the way through) You should then be able to get that new shiny fuse in there REAL easy!!! Of course this has NEVER happened to me, I learned all this from someone elses experience!  

[keitha43]

You used to be able to get hemostats from Radio Shack. They are your friend. You never know if the Dentist reviewed film of you stealing his and gets his revenge once you are in the chair.

[Penfold]

My brother's a dentist so I can always scavenge a tool from him if I so need ;-).

The idea that I am getting is since these fuses are through hole and the through holes are plated you could theoretically clip the leads down a bit and put them on the underside of the board and solder them with a small iron tip on the underside of the board.  Having those plated though holes could be a blessing in disguise.

[MrChristmas2000]

I made a tool for removing them by cutting a 6" section of wire hanger and making a small L-shaoe at the end of it. I then filed it down so it would fit beneath the fuse. It was either this or stealing the dentists instrument when he turned his back! LOL    Sometimes you may need to use a small flat headed screwdriver to push the fuse up a little from the bottom of the board and you might break a few fuses and have to pull them out with a needle nose pliers from the top while you heat the bottom. Finally, if the remaining solder clogs the pass through,  you might need to take a safety pin and bend it straight and press it at the top of the pass through while heating the bottom so that you get it all the way through the whole (this may require heating it 3 or 4 times to get it all the way through) You should then be able to get that new shiny fuse in there REAL easy!!! Of course this has NEVER happened to me, I learned all this from someone elses experience!  

I told my dentist that I needed some of his old instruments and he gave me a handful. They are great at helping removing components. They were particullarly handy to replace some fuses. I then put them on the bottom of the PCB.

[jnealand]

I have replaced several fuses.  It was not that hard to do.  I use the radio shack desoldering iron.  I for one would rather put my soldering iron on the bottom of the board than try to put it down between the sockets.  After you learn why you are blowing fuses hopefully you will not blow any more so thinking of fancy ways to mount or access them should be a moot point.  I have not blown another fuse since I screwed up the first couple by not keeping the loose wire ends at the far end of the string from touching.

[dpitts]

After you learn why you are blowing fuses hopefully you will not blow any more so thinking of fancy ways to mount or access them should be a moot point.

Why have the fuses if it is a moot point? And if the fuses are needed why not be able to express ideas that may make the fuses easier to replace for a future version of the hub?

[deplanche]

I've started using a passive hub (4) for all my testing.  Much easier to replace the fuses on those, and don't need to fully populate it to be able to use it. 

[urthegman]

I made a tool for removing them by cutting a 6" section of wire hanger and making a small L-shaoe at the end of it. I then filed it down so it would fit beneath the fuse. It was either this or stealing the dentists instrument when he turned his back! LOL    Sometimes you may need to use a small flat headed screwdriver to push the fuse up a little from the bottom of the board and you might break a few fuses and have to pull them out with a needle nose pliers from the top while you heat the bottom. Finally, if the remaining solder clogs the pass through,  you might need to take a safety pin and bend it straight and press it at the top of the pass through while heating the bottom so that you get it all the way through the whole (this may require heating it 3 or 4 times to get it all the way through) You should then be able to get that new shiny fuse in there REAL easy!!! Of course this has NEVER happened to me, I learned all this from someone elses experience!  

I told my dentist that I needed some of his old instruments and he gave me a handful. They are great at helping removing components. They were particullarly handy to replace some fuses. I then put them on the bottom of the PCB.

I will tell my "friend" to do this. 

[Nightowlz1966]

MrChristmas2000 told me about mounting them on the board backwards, so here is what that looks like as I took his advice.