The GND prong snapped on my power cable. Problem?

[Ike Zimbel]

Originally Posted by nms

Precisely. You know something's wrong when you scope a test point and see a big 60hz hum that shouldn't be there.

Simple open & shut case. GND pong broken? Replace the power cord!

A "ground pong" could be coming from a "stenchin' cord"

[ritelec]

nms...........friends???
it's all good right?

[ritelec]

play safe all

[nms]

Originally Posted by Ike Zimbel

A "ground pong" could be coming from a "stenchin' cord"

That's really the moral of the story here.

ground pong boken? won't fit da stenchin cord rite? Fix er up!

[Warren Beck]

Meh - everyone has an opinion. As for a shit storm hardly. Nice to see all those with degrees, 1000's of hours in design, installation on a global level of high end equipment are here. Floating a ground in a consumer device like a Roland keyboard is not a serious issue. You can not die (not like the famed Fender death capacitor in their early amplifyers).
Many countries have safety regulations. At times they are great and at times they are a HUGE PITA for manufacturers. And I have had to learn with American codes and deal with Canadian ones as well for many years. what some of you write is accurate to a point. BUT you soap box standing kids - it is a basic synthesizer. Not a tube amplifyer. We are not dealing with a half-million dollar boradcast console for the Olympics. Something that will exist within a hazardous and (in an audio perspective) dangerous environment (for RF, etc.). THUS a broken ground prong on a power cord is hardly worthy of this nonsense. Yes replace it when you have the chance - but your safety and life is definitely NOT in question/jeopardy here. In the context of the issue the client brought forth - so the GND prong snapped on the power cable to my analog synth (Roland Juno 60). Is this something to worry about? Should I solder a new cable in? - use it. Replace it when you have $20 to order it and have it shipped from Mouser, Electrosonic, or where ever.

It really is not an issue.

[ritelec]

Originally Posted by Warren Beck

Meh - everyone has an opinion. Floating a ground in a consumer device like a Roland keyboard is not a serious issue.

[ritelec]

Originally Posted by Warren Beck

Replace it when you have $20 to order it and have it shipped from Mouser, Electrosonic, or where ever.

It really is not an issue.

Take it out of service till it's repaired..............

I/We appreciate the "opinions"...............but your opinion is wrong.....sorry dude.

You got credentials? Insurance..........

I understand don't walk across the street you may get hit buy a bus........

But you shouldn't push someone into an unsafe possibly life threatening situation.

[ritelec]

Originally Posted by Warren Beck

THUS a broken ground prong on a power cord is hardly worthy of this nonsense.

Apparently you've never gotten a good/bad rap...or burn.

Apparently you've never been electrocuted or you would have not been alive to post.

[JohnRoberts]

Originally Posted by Warren Beck

Meh - everyone has an opinion. As for a shit storm hardly. Nice to see all those with degrees, 1000's of hours in design, installation on a global level of high end equipment are here. Floating a ground in a consumer device like a Roland keyboard is not a serious issue. You can not die (not like the famed Fender death capacitor in their early amplifyers).

People can and do die from 120V.

Removing a safety ground is rolling the statistical dice that you will not get a transformer or primary wiring fault that powers the chassis, in combination with your body becoming the return path. While rare, such faults can and do happen. I recall one incident where a faulty repair left an internal safety ground incorrectly attached inside the unit, and contributed to the owners death (during a baptism service, not one of my units thankfully).

Many countries have safety regulations. At times they are great and at times they are a HUGE PITA for manufacturers. And I have had to learn with American codes and deal with Canadian ones as well for many years. what some of you write is accurate to a point. BUT you soap box standing kids - it is a basic synthesizer. Not a tube amplifyer. We are not dealing with a half-million dollar boradcast console for the Olympics. Something that will exist within a hazardous and (in an audio perspective) dangerous environment (for RF, etc.). THUS a broken ground prong on a power cord is hardly worthy of this nonsense. Yes replace it when you have the chance - but your safety and life is definitely NOT in question/jeopardy here.

For the OP It is a matter of statistics, agreed pretty unlikely to take his life any time soon.

For people offering advice to the public, there is good reason to be conservative and accurate. The safety agency standards are often a PIA but generally they are founded on good science and reason. In this case if the product transformer is single insulated, it needs a grounded line cord (and grounded outlet for that safety ground to work). If it is a consumer product with double insulated transformer, perhaps the ground pin is not necessary. I do not know for a fact that the OP's product does not need a safety ground, and since it had a grounded line cord, I ASSume it needs it.

In the context of the issue the client brought forth - so the GND prong snapped on the power cable to my analog synth (Roland Juno 60). Is this something to worry about? Should I solder a new cable in? - use it. Replace it when you have $20 to order it and have it shipped from Mouser, Electrosonic, or where ever.

It really is not an issue.

Statistically speaking you are probably correct, but literally incorrect when you say

"but your safety and life is definitely NOT in question/jeopardy here.

it is unfortunately, albeit with low probability.

BTW internet advice on matters of life safety are worth exactly what you paid for it, including even mine.

JR

[nms]

Originally Posted by Warren Beck

use it. Replace it when you have $20 to order it and have it shipped from Mouser, Electrosonic, or where ever.
It really is not an issue.

Warren my good man, you've somehow missed that I mentioned in a few posts already about having fixed it:

Originally Posted by nms

That GND absolutely needed to be fixed. When I soldered a new cable in it grounded the synth properly. Prior to this there was a GND hum in the synth when no audio cables were plugged into it. Checking test points with a scope showed it clearly. With a grounded audio cable plugged in it would go away but it had a fierce hum with any cable that had the GND lifted at one end.

It really WAS an issue that needed to be taken care of so I dealt with it immediately. I wasn't worried about vapourizing myself since everything coming out of the PSU is low voltage, but a hum is an issue for recording or normal usage. This was an instance where using the "improper" cable (TRS to XLR from an unbalanced unit to balanced unit) concealed the ground problem. It's quietest with the proper cable and power cord fixed though which is the outcome I was after.

[Mixermend]

Always interesting to read discussions on safety earthing (or grounding) - in the USA, where I sometimes come away with the impression that you don't think your mains voltage is dangerous.

From a UK and European perspective - this is certainly NOT the case - as our mains voltage is 230 volts AC - and is absolutely to be given due respect.

We have a procedure known as 'PAT' testing (Portable Appliance Testing), which isn't strictly mandatory, but a test certificate will often be demanded by Theatres and other venues when musicians and PA companies bring in their equipment - as a condition of the venues insurance.

Part of this test requires a very low resistance path from any exposed metalwork to the earth or ground pin - which is essential to ensure that any fault current will blow the safety fuse or circuit breaker, rendering the equipment to fail safe.

As mentioned in previous posts - fault currents can have very high transient values - if and PCB track or Molex type pin header connectors are in the fault current path - they can easily burn out, effectively disconnecting the safety earth path - possibly rendering the metal chassis to be live.....

This why lifting mains earth/grounds and relying on instrument cable screens to provide a safety earth - for example when connecting two guitar amplifiers together - is a really bad idea.

In the final analysis - we don't want anyone to fry on stage, or in a quiet studio or at home.......

[ritelec]

Originally Posted by Mixermend

From a UK and European perspective - our mains voltage is 230 volts AC - and is absolutely to be given due respect.

Got hit with 277v with a load on it and 480v with no load........"Respect" it ...well put.

Nice post Mixermend.


Does the voltage kill you or the amperage..yet another debate.

play safe

[JohnRoberts]

Originally Posted by Mixermend

Always interesting to read discussions on safety earthing (or grounding) - in the USA, where I sometimes come away with the impression that you don't think your mains voltage is dangerous.

From a UK and European perspective - this is certainly NOT the case - as our mains voltage is 230 volts AC - and is absolutely to be given due respect.

We have a procedure known as 'PAT' testing (Portable Appliance Testing), which isn't strictly mandatory, but a test certificate will often be demanded by Theatres and other venues when musicians and PA companies bring in their equipment - as a condition of the venues insurance.

Part of this test requires a very low resistance path from any exposed metalwork to the earth or ground pin - which is essential to ensure that any fault current will blow the safety fuse or circuit breaker, rendering the equipment to fail safe.

As mentioned in previous posts - fault currents can have very high transient values - if and PCB track or Molex type pin header connectors are in the fault current path - they can easily burn out, effectively disconnecting the safety earth path - possibly rendering the metal chassis to be live.....

This why lifting mains earth/grounds and relying on instrument cable screens to provide a safety earth - for example when connecting two guitar amplifiers together - is a really bad idea.

In the final analysis - we don't want anyone to fry on stage, or in a quiet studio or at home.......

Indeed... 120V can and does kill people.

AFAIK In the US ground bonding is only required with 3 wire line cords, to external chassis points labelled as ground. Chassis grounding is good practice . 2 wire line cord products are double insulated around mains wiring, so the statistical probability of two insulation failures simultaneously is much less likely.

Your point about instrument cables being insufficient to conduct enough current to take out the mains fuse is well founded, but they can easily conduct enough current to stop a heart beating. I am aware of one death where the path that killed the guitar player was through his instrument cord.

JR

[ritelec]

Let us not forget clergy getting into a baptismal bath with a chorded mic.

Just a person diving into a lake off a dock can get it if equipotential planes are not installed.
Which is hard to do in a lake.

Live stock housing, pools........there is lost voltage and current flying around under our feet back to the generating station. Just being in the wrong place at the right time can kill you.

Watch out for Rover if you have him out and he's sniffing a light pole.

arf arf.......

[ritelec]

This ain't rock-n-roll...............

But if you have the chance to sit through it.......it's good.

Mike Holt discusses Stray Voltage

Rich

[ritelec]

thanks for the link rich,
I'm enjoying watching it again.
you're welcome rich.
next I may post some links for burns, and death by electricity.
thanks again rich,
your welcome ,
rich

[S2udio]

Originally Posted by ritelec

Does the voltage kill you or the amperage..yet another debate.

No debate just fact !

As always its the amount of current flowing across your ticker

50-60ma will kill most humans..., body resistance is the determining factor

I= V/R(body resistance)

DC kills easier than AC

[ritelec]

Originally Posted by S2udio

DC kills easier than AC

?thought ac did. That's why edison (I believe) invented the electric chair.to prove that point

"Thomas Edison didn't actually invent the electric chair but, paid Harold P. Brown to. It was invented because Thomas Edison's competitor Nikola Tesla had AC electricty (Edison had DC) and AC was cheaper but, more dangerous. Thomas Edison wanted people to know this (so more people would choose his over Tesla's) so he had it made and electrocuted William Kemmler (who had chopped up his wife and was sent to perison). this was called the war of currents"

[PRH]

AC is more dangerous.

AC of low current at around 50-60 Hz induces tetanic contraction of muscle, which can cause, for example, a hand to become fixed to the electrocuting source. AC also is more likely to disrupt the hearts pacemaker centre.

[S2udio]

You cant let go of DC if no ones around to pull you off
Muscles contract pulling you in, you burn.........

You die......AC/DC whatever.......unless we can make an A/B comparisson?

Any takers ?

BOT

No "so called" technician takes a safEty earth off any equipment and claims its

OK to do so !!!

[JohnRoberts]

AC or DC, voltage or current...

In practice it doesn't much matter which one killed you,, it would likely be AC just because that is the highest probability to be exposed to, but i suspect we could be killed by a 9V battery, driven through our heart like a vampire's wooden stake. :-(

JR