Gaming device potentially live case - help diagnosing needed

[Lucien Nunes]

Earth pin just inside the transformer and the other on the neutral pin

No, not the neutral or live! The negative side of the 5V or 12V DC output. You would be checking to see whether the incoming earth connection in the IEC is carried through to the DC output. If so, then there is no reason why the case of the unit should float up to some arbitrary AC voltage, therefore you have a fault which you must find. If the earth is not carried through the power supply unit, then it is legitimately floating and you can solve the problem by earthing the case.

If any doubt remains, the power supply units should be subjected to a standard 'PAT test' to ensure their integrity.

 

[static zap]

Could start by testing individual supplies in isolation.
(If none have voltage on them - may be getting generated)
.. Do any of instruments illuminate with "Electro Luminescence" -Blue green Glow. Those are a bit like
laptop /LCD-TV Backlights (Hi freq-inverter)

 

[DPG]

You need to find someone who is competent to do these tests for you. No offence intended, but you are putting yourself at too much risk here based on your level of electrical knowledge.

 

[B737]

Could start by testing individual supplies in isolation.
(If none have voltage on them - may be getting generated)
.. Do any of instruments illuminate with "Electro Luminescence" -Blue green Glow. Those are a bit like
laptop /LCD-TV Backlights (Hi freq-inverter)

There are lots of annunciators that illuminate when required. These are fed by the 5v main supply feed.

 

[static zap]

Stay safe , and be wary if any inverters are present , they are a hazard to other circuits as any of their output getting into 5V CMOS logic ,is a story with a sad ending. ( if its more recent design , I would hope for LED) ... this is where , experience comes in ...
And I've never touched anything that expensive looking !

 

[B737]

No, not the neutral or live! The negative side of the 5V or 12V DC output. You would be checking to see whether the incoming earth connection in the IEC is carried through to the DC output. If so, then there is no reason why the case of the unit should float up to some arbitrary AC voltage, therefore you have a fault which you must find. If the earth is not carried through the power supply unit, then it is legitimately floating and you can solve the problem by earthing the case.

If any doubt remains, the power supply units should be subjected to a standard 'PAT test' to ensure their integrity.

Hi

I did the above test today. I had my multi meter on circuit with sound and also tried it on 200 and 2k ohm and can confirm I never got a sound or a reading. When on ohm stayed on 1 which was the same as when not testing anything.

So I theory I could earth the case?

 

[B737]

Update.

Had an electrician round who just looked at the device and said the problem was simply that the metal case is isolated and the voltage reading is just jumping across from from the circuits inside (ghost/phantom voltage) and it can’t get away. It needs earthing to allow the AC phantom voltage to get away so I’ve ran a earth cable from the case and now I get 0 volts ac on my multi meter when testing the case to earth.

Next test is to see if I still need the ferrite beads on the usb cable.