mmitchell
Advanced Member level 4
Hi,
I would like to ask a question with short-circuit.
We have built a new board which has a power-management IC supplying various voltages of for board components. It has been tested to work fine. Today however, after some soldering work we forget to take the solder wire off the table before plugging power into the board, and I saw and smell a smoke from the board. It was obviously a short-circuit created somewhere due to the extremely well conducitivty of bare solder wire.
Then I found the device has stopped functioning. Of course the CPU doesn't work, and emulation attempts failed with messages saying that there is a CPU power loss. I suspect that the problem was due to the burning of the power management IC so I tested voltage at several output pins of it. Most of them measured zero as opposed to nominal values, and some give incorrect higher or lower non-zero values.
My question:
Matt
I would like to ask a question with short-circuit.
We have built a new board which has a power-management IC supplying various voltages of for board components. It has been tested to work fine. Today however, after some soldering work we forget to take the solder wire off the table before plugging power into the board, and I saw and smell a smoke from the board. It was obviously a short-circuit created somewhere due to the extremely well conducitivty of bare solder wire.
Then I found the device has stopped functioning. Of course the CPU doesn't work, and emulation attempts failed with messages saying that there is a CPU power loss. I suspect that the problem was due to the burning of the power management IC so I tested voltage at several output pins of it. Most of them measured zero as opposed to nominal values, and some give incorrect higher or lower non-zero values.
My question:
- Which are possible to have been damaged? When there is a short-circuit, circuit theory suggests that the current takes the path of the lowest resistance which is the path created between pins by the solder wire touching both, and it shall avoid the path with higher resistance. I therefore think that it is probably most components should be safe? For example, CPU and other ICs, since the theory doesn't suggest that they should have been burned by excessive current due to their non-zero resistance?
- Could the fix be as simple as just replacing the power management IC? Or there could also be other components that get damaged?
Matt
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