3A power supply exploded

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1

Hello,

Having a Raspberry Pi 3B+ booting from an SSD powered by the Pi
Unfortunately the SSD enclosure stopped working after a year, so I bought another one

I test and plug this enclosure into my PC, it boots without problems
I plug it into the Raspberry Pi 3B+ which also has an RFLink and a Sonoff Zigbee USB dongle attached
And there I see before my eyes the Pi’s 3A power supply explode!

Do you have an explanation why?
Could the devices connected to the USB ports have demanded power that exceeded 3A?

I checked: the SSD needs 1A, so that leaves the Pi, RFLink and Sonoff to power

For now I’ve used an old HDD enclosure with an external power supply, but the idea would be to have as few cables as possible, what advice do you have to avoid starting a fire and to ensure everything is powered correctly?

2

I think the power supply was faulty and that the fluctuations from plugging / unplugging caused it to fail.

No miracle solution for the cables unfortunately…
Having a PoE switch with a PoE HAT on the RPi lets you do without the power cable, but that requires spending extra money ^^

3

I opened the power supply; two capacitors had exploded and there is blackening in the middle of the board, so I imagine that once the capacitors exploded, it caused sparks on the rest of the board, hence the black marks.

By the way, is there a current limit per USB port on a Pi?
Because the SSD draws 1A

What reliable power supply would you recommend for this kind of 24/7 use with an SSD powered by the Pi?

The burned power supply lasted for four and a half years
It’s this model
https://a.aliexpress.com/_ExOqYJP

4

I believe the official Raspberry Pi power supplies are 3A.

5

I’ve just checked
For the Pi 4 the official power supplies are USB-C
And the official Pi 3 power supplies are only 2.5A, with micro USB

Are these two solutions equivalent in terms of safety?

  • use an official Pi 4 power supply and put a USB-C to micro USB adapter
  • use an official fast smartphone charger (brands Xiaomi, Samsung) at 3A or more and use a micro USB cable
6

I’m not at all knowledgeable about electricity… I’d rather not say something stupid!

7

Hi @NilkOne,
4 and a half years… a bit early — usually failures happen after 5 years! :slightly_smiling_face: It typically looks like a dry solder joint; 90% of electronic failures occur because solder dries out over time (or you spot them with a magnifying glass because there’s a sort of mechanical lifting around the edge of the solder and often crackling/noise)! In your case the power supply is trash, but for a TV or other device, sucking out the old solder and applying new solder very often fixes the fault :wink:

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