No power light anymore...

6 posts
by Guest » Sat Apr 21, 2012 8:38 pm
OK, after a week of playing with my RPi it no longer powers up. The power LED doesn't turn on. Tried a different power supply and get the same.

What options do I have?
by Guest » Sat Apr 21, 2012 8:53 pm
OK, now the power LED is flashing. Is that good?
by john_wage » Sat Apr 21, 2012 9:44 pm
make sure you don't have shorts anywhere.

for instance small metal flake might have wedged between solder points that don't belong to be connected.

things like this can happen when you handle uncased circuit board systems..
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by jbeale » Sat Apr 21, 2012 10:13 pm
Checking page 4 of the schematics, the red power LED (D6) is connected via 1K resistor directly to the +3.3V rail. It is not controlled by the CPU or any other circuit. So, if that LED is blinking, it means your 3.3V power is turning on and off. You've most likely got a broken connector, cable, or an intermittent short that is causing that.  If it's the D5 green status light, then I think blinking indicates SD card access.)
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by rew » Sun Apr 22, 2012 7:59 am
And similarly, the 3.3V is derived directly from the 5V with a robust 3.3V regulator. It is the black chip near the power inlet. Those things can handle most "mistreatments".

My conclusion is the same: Check out your 5V.
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by BertM » Mon Apr 23, 2012 1:28 am
What do you mean by "flashing"? Irregular flashing, twice every second, once every 10 seconds?

It will most likely be a short somewhere. The flashing you observe can be caused by

- A bad connection

- A faulty (external) power supply

- An overheating RG2 (the 3.3V regulator), most likely due to a short somewhere down the line

- Self-resetting of the 1.1A fuse, similar reasons as above

What voltage do you measure between TP1 and TP2?
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