Need help repairing a Casio WK-110

[mykdebauch]

so i just bought a casio WK-110 midi/keyboard for $15 at a goodwill. i was hoping there wasn't anything wrong with it but turns out there are 9 dead keys. i take it apart to fix it hoping i'd just have to adjust something or clean it but it looks like there's a broken wire in a wire belt. i've never tried to repair a wire before and just need some advice.









This is the wire im talking about, its exposed a bit. how do i go about fixing it?

 

[Harald Kapp]

It looks like the top 3 wires in the bottom image may be broken.
Cut them open.
Separate the strands such that you have 3 separate wires on each side of the cut.
Remove the insulation for ~5mm on each wire. Put a piece of shrink tube over the wire end - do not yet shrink it! Solder a bit of wire between the matching ends of the ribbon cable. Shift the shrink tube over the solder points, shrink it to insulate the connection.

Chances are that there's more damage to the cable than is visible. The canle looks a bit brittle, too. Replace the whole cable as an alternative to a repair.

 

[mykdebauch]

It looks like the top 3 wires in the bottom image may be broken.
Cut them open.
Separate the strands such that you have 3 separate wires on each side of the cut.
Remove the insulation for ~5mm on each wire. Put a piece of shrink tube over the wire end - do not yet shrink it! Solder a bit of wire between the matching ends of the ribbon cable. Shift the shrink tube over the solder points, shrink it to insulate the connection.

Chances are that there's more damage to the cable than is visible. The canle looks a bit brittle, too. Replace the whole cable as an alternative to a repair.

i thought it was more than one wire that was broken too but i looked, only one is severed, but the wire to the left of it is smashed though, but it looks like the rubber coating protected it.

 

[mykdebauch]

Oh yeah, one more thing, how do i strip the rubber off the cable so i can get access to the wire?

 

[davenn]

Oh yeah, one more thing, how do i strip the rubber off the cable so i can get access to the wire?

looks like only one damaged. have seen that fault before where some one has been careless when screwing up the housing of a bit of gear and got a
cable gammed between the screw mounts. Then when the screw is replaced it cuts through the cable

with fine side cutters or a handyman knife (exacto ? in the USA)
just careful slide the blade between the wire sections so you can pull up 1/2 an inch on each side of the break.
then use side cutters to strip off 1/4 inch of the plastic on the 2 wire ends
tin the bared ends of the wires with solder
use a short piece of patch wire and solder it between those 2 ends

easy repair, 15 minute job, done it many times and much faster and easier than replacing the whole cable

cheers
Dave

 

[(*steve*)]

And be very careful you don't slice through the insulation to reveal the wires on either side.

If you have to err, err on the side of being closer to the broken wire as you're going to strip that anyway.

Don't melt the cable while you're soldering.

Using heatshrink to cover the connections is ideal (but you need to be careful with it in cases like this that you don't prematurely shrink it.)

Otherwise, some insulation tape will work for a while. Cheap insulation tape will fall off after a while leaving a sticky mess. If you're not opening and closing the unit, it might stay in place enough to prevent anything shorting out.

 

[mykdebauch]

What kind of wire do i use to connect the two? i have a cheapo soldering iron and 40/60 rosin core solder, i don't know what kind of wire to use though.

And be very careful you don't slice through the insulation to reveal the wires on either side.

If you have to err, err on the side of being closer to the broken wire as you're going to strip that anyway.

Don't melt the cable while you're soldering.

Using heatshrink to cover the connections is ideal (but you need to be careful with it in cases like this that you don't prematurely shrink it.)

Otherwise, some insulation tape will work for a while. Cheap insulation tape will fall off after a while leaving a sticky mess. If you're not opening and closing the unit, it might stay in place enough to prevent anything shorting out.

 

[davenn]

any kind of multi stranded plastic covered wire with a similar diameter to any one of those individual wires within that ribbon

Dave