4 Replies Latest reply on May 30, 2019 1:03 AM by rahulprakasan

    Raspberry pi not booting

    rahulprakasan

      Hai... today by mistake 5v and 3.3v shorted, after that system is not booting now just see red light when am connecting to power supply. Is there any solution to repair my raspberry pi

        • Re: Raspberry pi not booting
          Roger Wolff

          No, not really,

           

          When you short the 5V and the 3.3V the (what should be) 3.3V suddenly becomes 5V. Not the other way around: There is a chip that makes the 3.3V from the 5V and it sees: Plenty of 3.3V, so I'll stay out of this, and it will let the voltage rise.

           

          That means you've put 5V on several chips that are rated for "Absolute maximum rating: 3.6V". Sometimes there is a bit of margin, sometimes not. I'm expecting you went beyond any margin there might have been. 

           

          In this case, I would expect your LAN9514 chip to be fried. It has a strict 3.6V max policy and no reason to be able to handle anything more.

           

          In this case, I would expect your SD card to be fried. (Test it somewhere else?) Same story.

           

          The CPU has parts that run on 1.2V and the 1.2V is made from the 5V. The IOs however officially run from 1.8V to 3.6V, but on the raspberry pi board those are connected to the 3.3V. So besides the LAN chip it is possible you've blown up the CPU.

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