Why does a spark appear when connecting USB to the motherboard?

Question

Iron

When connecting a USB port to the motherboard, a spark often appears between the connector and the
Tech connector. specifications
Motherboard: ASUS M5A97 r2.0 LE
Power supply: Zalman ZM450-GS

Answer 1

No, guys, this is not static and not USB 5 volts. This is a major electrical and (possibly) grounding problem. It can lead to burnout of USB ports, so I advise you to take it with all due care.
The first diagnostic action is to take a multimeter and measure the AC voltage between the cases (common wires) of both devices connected by a sparking cord. Since one of the possible reasons is an accidental grounding of one of the cases, you must do this without moving them away, otherwise, as it happened, it will end, and you will never know the reason. Write in the comments how much the multimeter showed, then I will continue my answer.

Answer 2

This is called static electricity (potential difference), a charge accumulates on you, which you transfer to a flash drive and sticking it into a computer you get a "special effect". And it's good that the spark jumps precisely between the connector and the connector, that is, their metal parts, which means they are well made and equalize the potentials of you and the computer case, instead of passing through the discharge through the data or power circuits, which kills both the flash drive and the computer.
Check if the computer is grounded, i.e. the third "prong" of the plug (and socket) is connected to ground.
- If grounded, put a 10 MΩ resistor across the wire (greater resistance will eliminate painful shocks and possible damage from a large charge, allowing the accumulated to drain more slowly).
- If it is not grounded, which is unlikely, then it is necessary to remove static electricity from yourself (and surrounding objects): increase the humidity in the room(s), ground linoleum and carpets.

Answer 3

This is the absence of a common ground between the two devices.

Answer 4

it is not described which gadget gives a spark when connected to usb.
for example, a printer / scanner, then with a bad power supply, potential "leakage" from the network to the device case is possible. it's not so terrible, but it's better to fix it.

Answer 5

You're right about the printer. I would also like to check if the motherboard sits on the case normally ... maybe it closes somewhere. In general, this should not be.
It happened a couple of times with cheap office buildings and shitty laminate. Boom accumulated static by shuffling across the floor, then when the flash drive was inserted, it sparked ...
So, in any case, check everything and treat it. To begin with, take out the motherboard, put it on the table (do not forget to put insulation, such as a package from the motherboard kit) and in this state try to shove usb.

Answer 6

spark at 5 volts?
there is a maximum current of amperes,
static remains (it would have taken out all the ports)
there is one more option °‿° (I experienced the shock myself, not long ago)
here, in the last answer, there is my comment https://toster.ru/answer?answer_id =1273108#comment...