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I have blown up my PI!

Posted: Sat Sep 03, 2016 10:21 am
by MohitBagur
Hello there!
I was tinkering around with my Pi3 yesterday, and i managed to reverse-polarity the GPIO power rail. My power supply had a short protection, but now my RPi does't seem to boot at all.. No magic smoke observed, no heating anywhere, I've checked with 2 SD Cards, but still the PWR LED is on and the ACT LED is off. I'm using a 5V/2A supply. Please help!!
Mohit :oops: :oops: :oops: :oops:

Re: RPi3 PWR LED on, ACT LED off

Posted: Sat Sep 03, 2016 11:53 am
by Greg Erskine
Replace RPI3 with a new one.

Re: I have blown up my PI!

Posted: Sat Sep 03, 2016 2:51 pm
by MarkR
If it was the 5V rail, that doesn't go into the soc, so you might be ok? Maybe.

If you have the skills and can get the parts, try replacing voltage regulator components?

Maybe it will power on if you put 3v3 on the 3v3 rail?

Worth a try?

Re: I have blown up my PI!

Posted: Sat Sep 03, 2016 3:10 pm
by davidcoton
Reverse polarity on GPIO connector = Fried Pi. This method of providing power bypasses the polyfuse protection, so it's up to you to get it right. I see very little hope of your Pi ever working again. Time to get a new Pi.

Re: I have blown up my PI!

Posted: Sat Sep 03, 2016 4:11 pm
by MohitBagur
The interesting thing is, the power LED still is on and I don't see any magic smoke or heating anywhere even after I've left it plugged in for the last six hours... :cry:

Re: RPi3 PWR LED on, ACT LED off

Posted: Sat Sep 03, 2016 4:12 pm
by MohitBagur
Greg Erskine wrote:Replace RPI3 with a new one.
Maybe I could try that. :lol:

Re: I have blown up my PI!

Posted: Sat Sep 03, 2016 4:29 pm
by MohitBagur
davidcoton wrote:Reverse polarity on GPIO connector = Fried Pi. This method of providing power bypasses the polyfuse protection, so it's up to you to get it right. I see very little hope of your Pi ever working again. Time to get a new Pi.
Can't anything be done?

Re: I have blown up my PI!

Posted: Sat Sep 03, 2016 4:31 pm
by kusti8
MohitBagur wrote:
davidcoton wrote:Reverse polarity on GPIO connector = Fried Pi. This method of providing power bypasses the polyfuse protection, so it's up to you to get it right. I see very little hope of your Pi ever working again. Time to get a new Pi.
Can't anything be done?
No. Chances are it's dead.

Re: I have blown up my PI!

Posted: Sat Sep 03, 2016 4:33 pm
by MohitBagur
kusti8 wrote:
MohitBagur wrote:
davidcoton wrote:Reverse polarity on GPIO connector = Fried Pi. This method of providing power bypasses the polyfuse protection, so it's up to you to get it right. I see very little hope of your Pi ever working again. Time to get a new Pi.
Can't anything be done?
No. Chances are it's dead.
If it was the 5V rail, that doesn't go into the soc, so you might be ok? Maybe.

If you have the skills and can get the parts, try replacing voltage regulator components?

Maybe it will power on if you put 3v3 on the 3v3 rail?

Worth a try?
what about this?

Re: I have blown up my PI!

Posted: Sat Sep 03, 2016 4:39 pm
by kusti8
You're going to spend much more time and money than it is worth to get a new Pi. That is not an easy thing to do.

Re: I have blown up my PI!

Posted: Sat Sep 03, 2016 5:19 pm
by stderr
MohitBagur wrote:
davidcoton wrote:Reverse polarity on GPIO connector = Fried Pi. This method of providing power bypasses the polyfuse protection, so it's up to you to get it right. I see very little hope of your Pi ever working again. Time to get a new Pi.
Can't anything be done?
I think that this clip from the Red Dwarf will be illustrative, taking only about four minutes to make its point: https://www.youtube.com/watch?v=nyKF2qd0-iQ

Re: I have blown up my PI!

Posted: Sat Sep 03, 2016 6:12 pm
by drgeoff
MarkR wrote:If it was the 5V rail, that doesn't go into the soc, so you might be ok? Maybe.

If you have the skills and can get the parts, try replacing voltage regulator components?

Maybe it will power on if you put 3v3 on the 3v3 rail?

Worth a try?
Doesn't the 5 volt rail on the GPIO header also connect directly to the LAN/USB chip.

Re: I have blown up my PI!

Posted: Sat Sep 03, 2016 8:45 pm
by davidcoton
drgeoff wrote: Doesn't the 5 volt rail on the GPIO header also connect directly to the LAN/USB chip.
Don't have a Pi3B schematic, but on the 1B 5V goes to HDMI and USB, but probably not in a way that damages the controllers (supplies are 3V3). However I would be surprised if the 3V3 regulator prevented damage propagating further. The cost of investigation and component replacement far exceeds the cost of a new Pi.

Re: I have blown up my PI!

Posted: Sun Sep 04, 2016 9:49 pm
by MarkR
Yes, the cost of investigating DOES exceed the price of a new Pi.

But that's not the point. We investigate to learn, not in the hope of a (unlikely) cost-effective fix.

Mark

Re: I have blown up my PI!

Posted: Sun Sep 04, 2016 10:19 pm
by davidcoton
MarkR wrote:Yes, the cost of investigating DOES exceed the price of a new Pi.

But that's not the point. We investigate to learn, not in the hope of a (unlikely) cost-effective fix.

Mark
Great philosophy (I'm not being sarcastic, I really agree that investigating mistakes can lead to learning).

In this case, if you have SMT rework equipment, good eyesight, lots of time, and oodles of patience, you might learn that it's better not to reverse supply polarity ... or better, you could spend a lot less time and effort, look at the Pi power circuits, and incorporate proper protection when next powering a Pi through the GPIO connector.

Even learning needs to be cost effective. :shock:

Re: I have blown up my PI!

Posted: Fri Sep 09, 2016 9:30 am
by MohitBagur
Don't know what luck I had, but, I powered the Pi up using a 3v3 supply connected directly to the 3v3 rail and GND, and 5v thru regular Micro-USB.. The ACT LED came on for a couple seconds, and again went off.