i need to replace a 3 pronged grounded power chord with a 3 pronged grounded jack how do i do this without risks ?

on my guitar amp the ground prong broke out of the plug so i need to replace that with a jack such as one found on a PC power source but i dont know what is positive and negative or how to prevent enternal damage fires or shock

* i posted i picture my connector looks like the one on the left only mine does not have leads only contacts sorry if i wasnt clear on what i was saying
*i have a second one of these with leads from a computer power source with wire leads but its a little differant it as a blue and brown instead of black and white wires and it also has a small yellow box that connects to bot contacts(excluding ground) which of these will work beter for a guitar amp

Picture of i need to replace a 3 pronged grounded power chord with a 3 pronged grounded jack how do i do this without risks ?
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framistan7 years ago
This is for electric in USA only. I am not familiar with european wiring systems. This also pertains to 120 volt systems only, not 220. The BLACK wire is hot.. and the WHITE wire is neutral. Green wire is GROUND. Notice on the connector that one terminal screw looks SILVERISH... the other one looks like BRASS color. The black wire goes to the BRASS color screw. The White wire goes to the silvery colored screw. Now to double check your work, you will notice one "blade" or "SLOT" of the connector fits a WIDE slot, and the other one fits a NARROW slot. The 3rd pin is round-ish and that is GREEN/GROUND. Check your wiring and your WHITE wire should be going to the WIDE slot. The other wire (BLACK) goes to the narrow. That was the LONG description of how to do it... here's the quick memory trick I use to help me remember.... "WHITE IS WIDE"... and "BLACK IS BRASS" If you are unsure of your ability to do this job... just ask someone at your hardware store. If you are under 18.. ask your parents for help. Don't do what a friend of mine did. She wired her cut vacuum cleaner cord pretty good... White to white... black to black... and green to green. Then she twisted them all together and taped them up!!! POW... she blew the fuse instantly!
fastcar123 (author)  framistan7 years ago
this is running off of 110 in USA its a little jack that lets you remove the chord they can be found on PC power sorces or on many other guitar amps unfortunatly this is soldered into the motherborad of the ampso the only screw is the on connecting the ground i always thought black was neutral and white was hot but it doesnt appear to be that way
If the jack is directly connected to the motherboard, you need a hefty soldering iron and a replacement recepticle. That might be a bit hard to find, so you may want to use a grounded extension cord cut off (the male end) -- Solder the wire directly to the board (providing strain relief with a knot or something) then use the new power plug.
fastcar123 (author)  frollard7 years ago
so just rplace a new chod an dont worry about the jack?
Essentially yes. Finding an identical board-mount connector may be a problem, so just solder the wires on per what fram describes above -- ground to ground, neutral to neutral, and hot to hot. Use a continuity tester to find which pin is which connection (if they are not labelled on the motherboard.
fastcar123 (author)  frollard7 years ago
ok so just place the chord no jack i can do that lets just say i tried to run the amp with no ground like it is now what could happin
Ground has 2 purposes -- 1 is a safety. If anything in the circuit faults and shorts to something it shouldn't the shortest path should be to ground. Without that you stand a fire risk and electrocution risk. Second reason: In audio applications grounding the amplifier *should* reduce noise introduced from other EM sources (such as the 60 hz hum from the wall power).
fastcar123 (author)  frollard7 years ago
ok so running the amp now is not safe considering that i have a kill switch on the guitar now the signal cant be grounded and has no where to go
I never said neglect the ground -- install the new cable with grounding!
fastcar123 (author)  frollard7 years ago
i know i was just saying that a fire is bad if its internal and i dont want a high voltage power to run back throught the guitar and ruin my guitar and shock me
Re-design7 years ago

There is no plus and minus in A/C electricity.  Here's a good diagram explaining how its hooked up.
There is, however, hot and neutral (in addition to safety ground). In double-insulated equipment you can get away with cheating on that, in other equipment it's really better to make sure hot and neutral are correctly hooked up, Just In Case.