komarek
Posts: 146
Joined: Fri Mar 31, 2017 1:19 am

Bricked my Pi. don't know why

Thu Jul 20, 2017 8:29 am

hi
yesterday was a sad day
i burned my Raspberry Pi zero W and i m still trying to understand why.

this is what i did
i'm having my power source by a 12v DC and 0.3A power supply... then i used a stepdown DC-DC converter to have a 5v DC output.
i decided to send it through the usb port (i thought that it would be less dangerous than gpio way)... so i've cut a micro-usb cable and i connected the 5v to the red wire and the ground to the black wire, then i cut the 2 data-wires (green and white).

Immediately after i connected the micro usb cable the Raspberry started to produce bad smell and smoke, i couldn't see exactly where, it was around the cpu. i disconnected the supply immediately but it was too late. The Raspberry is not powering up anymore... and i'm trying to understand what really happened.

What can you tell me?
is there any test i can try to understand what happened?
thanks folks

komarek
Posts: 146
Joined: Fri Mar 31, 2017 1:19 am

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 8:41 am

i used this connector
Attachments
screenshot 2017-07-20 alle 10.41.07.jpg
screenshot 2017-07-20 alle 10.41.07.jpg (26.72 KiB) Viewed 3283 times

User avatar
RaTTuS
Posts: 10493
Joined: Tue Nov 29, 2011 11:12 am
Location: North West UK

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 8:45 am

either it was 12V
or
you swapped the +Ve and -Ve on the Micro USb
the PI0 does not have any power protection circuit
How To ask Questions :- http://www.catb.org/esr/faqs/smart-questions.html
WARNING - some parts of this post may be erroneous YMMV

1QC43qbL5FySu2Pi51vGqKqxy3UiJgukSX
Covfefe

komarek
Posts: 146
Joined: Fri Mar 31, 2017 1:19 am

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 8:48 am

RaTTuS wrote:either it was 12V
or
you swapped the +Ve and -Ve on the Micro USb
the PI0 does not have any power protection circuit
i'm 100% sure it was 5V cause i tested it.
my first doubt it was actually i've inverted VCC and GROUND on the wires..
but it's actually strange to make such a stupid mistake for me. I Threw the connector away immediately after i saw the smoke. so i couldn't check that thing after the damage.
Is that any way i can test where the problem came from now?

pcmanbob
Posts: 7133
Joined: Fri May 31, 2013 9:28 pm
Location: Mansfield UK

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 9:17 am

Which DC-DC converter were you using , some of them require the output to be setup before you connect it to your pi and how accurate is the meter you were using , have you tested it on a known source voltage to see if it is actually any were near accurate.

you must have either reversed the connection supplying the pi or supplied to higher voltage, only options to have caused this.
We want information… information… information........................no information no help
The use of crystal balls & mind reading are not supported

komarek
Posts: 146
Joined: Fri Mar 31, 2017 1:19 am

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 9:45 am

pcmanbob wrote:Which DC-DC converter were you using , some of them require the output to be setup before you connect it to your pi and how accurate is the meter you were using , have you tested it on a known source voltage to see if it is actually any were near accurate.

you must have either reversed the connection supplying the pi or supplied to higher voltage, only options to have caused this.
i used this
http://www.hotmcu.com/mp1584-buck-step- ... -p-82.html

and yes. the measurement was accurate

BMS Doug
Posts: 3824
Joined: Thu Mar 27, 2014 2:42 pm
Location: London, UK

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 9:58 am

So, two possibilities:

Your power supply was inverted and you put 5V onto Gnd and Gnd to 5V (Fairly unlikely as they are pretty well marked on your kit and you had tested it.

(Speculation): Your 12V 0.3A (3.6W) supply couldn't cope with the load of the pi and its power became unstable, dipping and rising as the converter drew from it. The Fluctuating 12V power supply caused the MP1584 output voltage to similarly fluctuate, rising too high and burning out the pi.
Doug.
Building Management Systems Engineer.

komarek
Posts: 146
Joined: Fri Mar 31, 2017 1:19 am

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 10:09 am

BMS Doug wrote:So, two possibilities:

(Speculation): Your 12V 0.3A (3.6W) supply couldn't cope with the load of the pi and its power became unstable, dipping and rising as the converter drew from it. The Fluctuating 12V power supply caused the MP1584 output voltage to similarly fluctuate, rising too high and burning out the pi.
this is quite interesting
so how shall i avoid this situation in the future (assuming that this was the problem) with my new raspberry i just bought?
and is there any way to test if actually the power supply or the converter become unstable without breaking anything else?

User avatar
Mortimer
Posts: 923
Joined: Sun Jun 10, 2012 3:57 pm

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 10:21 am

After watching quite a few BigClive videos on YouTube it is apparent that many USB leads coming from China cannot be trusted to have the correct colours on the power lines. He frequently finds +5V is white and ground is red.

Always continuity check such connections and make sure connections are going to where you expect them to.
--------------
The purpose of a little toe is to ensure you keep your furniture in the right place.

pcmanbob
Posts: 7133
Joined: Fri May 31, 2013 9:28 pm
Location: Mansfield UK

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 10:38 am

komarek wrote: this is quite interesting
so how shall i avoid this situation in the future (assuming that this was the problem) with my new raspberry i just bought?
and is there any way to test if actually the power supply or the converter become unstable without breaking anything else?

Why don't you just buy a 5V pi power supply with the correct rating ?

If you want to use a 12v power supply and a DC-DC converter you are going to need a 12v 1A power supply as a minimum, I have one running a pi2 project that includes pi, 20x4 LCD and 10 LED bar graph display.
We want information… information… information........................no information no help
The use of crystal balls & mind reading are not supported

komarek
Posts: 146
Joined: Fri Mar 31, 2017 1:19 am

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 10:43 am

Mortimer wrote:After watching quite a few BigClive videos on YouTube it is apparent that many USB leads coming from China cannot be trusted to have the correct colours on the power lines. He frequently finds +5V is white and ground is red.

Always continuity check such connections and make sure connections are going to where you expect them to.
oh god.
i assumed the colors were correct.
so... is there any way to check if the wires color are actually red for VCC and black for ground without breaking anything else?

komarek
Posts: 146
Joined: Fri Mar 31, 2017 1:19 am

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 10:45 am

Why don't you just buy a 5V pi power supply with the correct rating ?

If you want to use a 12v power supply and a DC-DC converter you are going to need a 12v 1A power supply as a minimum, I have one running a pi2 project that includes pi, 20x4 LCD and 10 LED bar graph display.
well
cause i need to put the PI inside a small box where i have 12V but i don't have 220V to plug the power supply you talk about... and, anyway, there would not be space enough

pcmanbob
Posts: 7133
Joined: Fri May 31, 2013 9:28 pm
Location: Mansfield UK

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 10:51 am

why not just buy micro usb plugs form some were like ebay and make your own leads that way you can use correctly sized wire and make sure its wired correctly.

http://www.ebay.co.uk/itm/10PCS-New-Mic ... SwXYtY07uA

plug wiring pin out http://neverstopbuilding.com/wiring-micro-usb-pinout
We want information… information… information........................no information no help
The use of crystal balls & mind reading are not supported

komarek
Posts: 146
Joined: Fri Mar 31, 2017 1:19 am

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 10:53 am

pcmanbob wrote:why not just buy micro usb plugs form some were like ebay and make your own leads that way you can use correctly sized wire and make sure its wired correctly.

http://www.ebay.co.uk/itm/10PCS-New-Mic ... SwXYtY07uA
well
because it took forever to have those things shipped and i had a cable ready in my desk to do the operation...
plus: as BMS Doug said the problem could be an unstable power supply behavior

User avatar
Mortimer
Posts: 923
Joined: Sun Jun 10, 2012 3:57 pm

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 10:56 am

komarek wrote:
Mortimer wrote:After watching quite a few BigClive videos on YouTube it is apparent that many USB leads coming from China cannot be trusted to have the correct colours on the power lines. He frequently finds +5V is white and ground is red.

Always continuity check such connections and make sure connections are going to where you expect them to.
oh god.
i assumed the colors were correct.
so... is there any way to check if the wires color are actually red for VCC and black for ground without breaking anything else?

I would plug your DC-DC converter into the Pi without power attached, and just buzz out the connections and check that there is continuity from the +5V of the converter to the +5V GPIO pin on the Pi, and likewise for Ground.
--------------
The purpose of a little toe is to ensure you keep your furniture in the right place.

User avatar
Mortimer
Posts: 923
Joined: Sun Jun 10, 2012 3:57 pm

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 10:58 am

We have a saying "Assumption is the mother of all mistakes". The language is usually a bit stronger, bit it is a good expression to keep in mind.

I suppose to be completely PC : "Assumption is the parent of all mistakes." :D
--------------
The purpose of a little toe is to ensure you keep your furniture in the right place.

komarek
Posts: 146
Joined: Fri Mar 31, 2017 1:19 am

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 11:03 am

shot.jpg
the same usb connector plugged to a chinese fan
shot.jpg (33.47 KiB) Viewed 3110 times
shot.jpg
the same usb connector plugged to a chinese fan
shot.jpg (33.47 KiB) Viewed 3110 times
Mortimer wrote:After watching quite a few BigClive videos on YouTube it is apparent that many USB leads coming from China cannot be trusted to have the correct colours on the power lines. He frequently finds +5V is white and ground is red.

Always continuity check such connections and make sure connections are going to where you expect them to.

the wires seem to be ok however
cause the chinese fan in the picture just uses 2 wires... and they have to be the 2 i've connected to a 5v power supply

pcmanbob
Posts: 7133
Joined: Fri May 31, 2013 9:28 pm
Location: Mansfield UK

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 11:10 am

komarek wrote:
pcmanbob wrote:why not just buy micro usb plugs form some were like ebay and make your own leads that way you can use correctly sized wire and make sure its wired correctly.

http://www.ebay.co.uk/itm/10PCS-New-Mic ... SwXYtY07uA
well
because it took forever to have those things shipped and i had a cable ready in my desk to do the operation...
plus: as BMS Doug said the problem could be an unstable power supply behavior

Well you will need about 300mA at 5.1v to run a pi zero as an absolute minimum, which is 1.53 watts.
So your psu supplying 12v at 0.3A should be able to supply it, BUT if the psu is actually a battery charger it is quite possible that it will not supply 0.3A at 12v, to test your set-up with out risking your pi you could connect a resistance of 17 ohms ( rated at 1.5watts) and then try measuring the voltage output of your DC-DC converter.
We want information… information… information........................no information no help
The use of crystal balls & mind reading are not supported

komarek
Posts: 146
Joined: Fri Mar 31, 2017 1:19 am

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 11:16 am

pcmanbob wrote:
komarek wrote:
pcmanbob wrote:why not just buy micro usb plugs form some were like ebay and make your own leads that way you can use correctly sized wire and make sure its wired correctly.

http://www.ebay.co.uk/itm/10PCS-New-Mic ... SwXYtY07uA
well
because it took forever to have those things shipped and i had a cable ready in my desk to do the operation...
plus: as BMS Doug said the problem could be an unstable power supply behavior

Well you will need about 300mA at 5.1v to run a pi zero as an absolute minimum, which is 1.53 watts.
So your psu supplying 12v at 0.3A should be able to supply it, BUT if the psu is actually a battery charger it is quite possible that it will not supply 0.3A at 12v, to test your set-up with out risking your pi you could connect a resistance of 17 ohms ( rated at 1.5watts) and then try measuring the voltage output of your DC-DC converter.
the PSU is actually a power supply unit for a intercom/doorbell system... it produces 12VAC and 12VDC at the same time.

ps.
The 12VAC is used to ring the bell and i already used that to switch one gpio to TRUE (with a diodes rectifier bridge and a voltage reductor circuit) and it was perfectly working...
but this is another story... and that circuit was not connected when i burned my PI

pcmanbob
Posts: 7133
Joined: Fri May 31, 2013 9:28 pm
Location: Mansfield UK

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 11:22 am

komarek wrote:
the PSU is actually a power supply unit for a intercom/doorbell system... it produces 12VAC and 12VDC at the same time.

ps.
The 12VAC is used to ring the bell and i already used that to switch one gpio to TRUE (with a diodes rectifier bridge and a voltage reductor circuit) and it was perfectly working...
but this is another story... and that circuit was not connected when i burned my PI

if you think the psu may be the cause of the problem then run the test , you may be able to use the fan as your load if it draws sufficient mA.

Don't forget your intercom/bell is using the psu as well so you may not have 12v at 0.3A available for the pi
Last edited by pcmanbob on Thu Jul 20, 2017 11:25 am, edited 1 time in total.
We want information… information… information........................no information no help
The use of crystal balls & mind reading are not supported

komarek
Posts: 146
Joined: Fri Mar 31, 2017 1:19 am

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 11:24 am

pcmanbob wrote:
komarek wrote:
the PSU is actually a power supply unit for a intercom/doorbell system... it produces 12VAC and 12VDC at the same time.

ps.
The 12VAC is used to ring the bell and i already used that to switch one gpio to TRUE (with a diodes rectifier bridge and a voltage reductor circuit) and it was perfectly working...
but this is another story... and that circuit was not connected when i burned my PI

if you think the psu may be the cause of the problem then run the test , you may be able to use the fan as your load if it draws sufficient mA.
the fan is connected with a battery charger system with a 5v rechargeable battery inside

sparkyhall
Posts: 145
Joined: Mon Aug 27, 2012 9:14 am

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 4:19 pm

I have several of these dc-dc convertors and the output voltage is not stable. In my case I needed to step down from 24V to 5V for a Pi3, before connecting the Pi I set the output voltage with a dummy load resistor of 8Ω while observing the output with an oscilloscope. This revealed that the output was oscillating between around 4-6V, I can't remember the frequency of oscillation but I do recall my multi-meter showing a stable 5V, presumably due to averaging. It appears, as supplied, that these do not have a large enough output smoothing capacitor. In my case I was able to eliminate the oscillations by placing a 100uF cap on the output of the dc-dc.

If your dc-dc behaved the same as mine then it may well have been the reason for your Pi demise.

komarek
Posts: 146
Joined: Fri Mar 31, 2017 1:19 am

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 4:24 pm

sparkyhall wrote:I have several of these dc-dc convertors and the output voltage is not stable. In my case I needed to step down from 24V to 5V for a Pi3, before connecting the Pi I set the output voltage with a dummy load resistor of 8Ω while observing the output with an oscilloscope. This revealed that the output was oscillating between around 4-6V, I can't remember the frequency of oscillation but I do recall my multi-meter showing a stable 5V, presumably due to averaging. It appears, as supplied, that these do not have a large enough output smoothing capacitor. In my case I was able to eliminate the oscillations by placing a 100uF cap on the output of the dc-dc.

If your dc-dc behaved the same as mine then it may well have been the reason for your Pi demise.
i see
but excuse me one question... the Raspberry doesn't have a circuit for protection about these voltage fluctuations through the micro usb port?
The device started to burn and smoking. sounds too much for 1 or 2 volts difference

pcmanbob
Posts: 7133
Joined: Fri May 31, 2013 9:28 pm
Location: Mansfield UK

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 4:31 pm

komarek wrote: i see
but excuse me one question... the Raspberry doesn't have a circuit for protection about these voltage fluctuations through the micro usb port?
The device started to burn and smoking. sounds too much for 1 or 2 volts difference

No the pi zero does not have any input protection unlike the pi2 or pi3, and 6v - 7v would probably be sufficient to destroy the voltage regulator circuit on the pi
We want information… information… information........................no information no help
The use of crystal balls & mind reading are not supported

komarek
Posts: 146
Joined: Fri Mar 31, 2017 1:19 am

Re: Bricked my Pi. don't know why

Thu Jul 20, 2017 4:39 pm

pcmanbob wrote:
komarek wrote: i see
but excuse me one question... the Raspberry doesn't have a circuit for protection about these voltage fluctuations through the micro usb port?
The device started to burn and smoking. sounds too much for 1 or 2 volts difference

No the pi zero does not have any input protection unlike the pi2 or pi3, and 6v - 7v would probably be sufficient to destroy the voltage regulator circuit on the pi
wow

Return to “General discussion”