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Raspberry turns on, hot CPU, ethernet and USB not working

Posted: Tue Dec 10, 2013 9:16 am
by Yaceq
I've got problem with my RPi. USB ports and ethernet don't work now, CPU is getting hot in a few seconds but RPi boots - HDMI output works and I can see it in the screen... Before its description I'll give you more details what Im using RPi for cause it might be needed. It'll be quite long but I want to give as many details as I can cause this problem is strange for me.

It's used for studies project - small robot with webcam and controlled via wifi from computer program. Webcam is mounted on small servo so that I can rotate it. Servo's PWM pin is connected directly to RPi pin, two other servo's pins (5V and GND) are connected to mine LiPol battery after voltage balancer that gives me 5V. I use two small motors that're connected to L293D driver. This driver is connected directly to RPi (3,3V is enough for this driver to recognize high state). I also use popular Edimax as wifi. As I said I use voltage balancer to get 5V from mine 2S LiPol. It works fine, whenever I check voltage it gives about 4,98V.

This configuration (without servo) has been working fine since September. I didn't have any problems with it. Webcam worked, wifi too. Motors have been connected this way since September too and it's been working fine as I said.
Servo was connected to this robot over a week ago. I tested it and it worked fine, motors too. Everything was good and I didn't suspect that I'd have such problems with it... Now more details about what happened.

It began about a week ago, I had a problem with booting Rpi - it's written here http://www.raspberrypi.org/phpBB3/viewt ... 37#p463737 . As you can see in this thread it was solved. I managed to run RPi after adding this line to config file. What only stopped working was... pin that servo's PWM was connected to. I had no idea why, I couldn't get PWM using this pin (it was pin GPIO 2 (rev. 2 board) http://elinux.org/RPi_Low-level_periphe ... .28GPIO.29). So I changed this pin to other (GPIO 11) and servo was working again. I checked everything - motors, webcam, wifi and servo - everything was ok. So I turned it off...

Day later mine RPi few secs after turning power on just turned off. What was interesting here - only one motor turned on for one or two secs, robot moved a few centimeters (this motor turned on immediately after I plugged in RPi). I unplugged it from LiPol battery and tried to turn on again but red LED just lighted for about one or two secs and it was down again... I searched internet for any info and found this: http://elinux.org/R-Pi_Troubleshooting#GPIO . It seemed to describe mine problem, I had problem with GPIO pins and RPi turned off. I waited about 6h and tried to turn on Rpi again. It turned on but only for about 10 secs... Next I tried in about 30h again. And it was good! RPi turned on, but... from this moment I've got this problem - USB and ethernet don't work, CPU is getting hot in a few seconds. I can see that it's working cause HDMI works. It boots, waits for login details. But I can't even log in cause I can't connect keyboard nor use SSH :( And the CPU... it's getting hot in a few seconds, after a minute I can't even touch it more than about 5 seconds, it's so hot...

What happened? Is this RPi dead and nothing can help it?
I'm the most interested in the reason, why did it happen. I have to finish this project in a month, I can buy new RPi but don't want something like this to happen again that's why I gave you all details. What did I do wrong?

Re: Raspberry turns on, hot CPU, ethernet and USB not workin

Posted: Tue Dec 10, 2013 9:39 am
by RaTTuS
how did you protect the gpio pin from being overloaded ?

Re: Raspberry turns on, hot CPU, ethernet and USB not workin

Posted: Tue Dec 10, 2013 10:24 am
by Yaceq
I didn't have any protection. I thought I don't need it.
L293D driver that is connected to RPi for high level gets max 100uA. For low level max -100uA. Values from datasheet - http://users.ece.utexas.edu/~valvano/Da ... /L293d.pdf
I use this servo TowerPro SG90. I read that it's safe to connect the pwm pin directly to RPi... http://learn.adafruit.com/adafruits-ras ... r/hardware

Re: Raspberry turns on, hot CPU, ethernet and USB not workin

Posted: Wed Dec 11, 2013 1:08 pm
by Yaceq
I just wanted to add that these two problems happened during turning on RPi I think (or turning off?). Before these problems occurred I used mine robot, I was driving it, using camera and rotating it and everything was ok. After unplugging it from LiPol and voltage stabilizer and plugging it again these problems occurred.
Can it be connected with this http://www.raspberrypi.org/phpBB3/viewt ... 29&t=47965 ?

Re: Raspberry turns on, hot CPU, ethernet and USB not workin

Posted: Sun Dec 15, 2013 10:36 pm
by emmaanuel
Hi,
I have exactly the same problem.
Hot cpu, no ethernet and no usb ...
The raspberry boot up (seen with serial connexion) but look like very slow.
I've tried with a fresh image of raspbian but with the same problem.

Re: Raspberry turns on, hot CPU, ethernet and USB not workin

Posted: Mon Dec 16, 2013 9:53 am
by RaTTuS
emmaanuel wrote:Hi,
I have exactly the same problem.
Hot cpu, no ethernet and no usb ...
The raspberry boot up (seen with serial connexion) but look like very slow.
I've tried with a fresh image of raspbian but with the same problem.
I'm not sure if you do have the same issue TBH

how hot ?
is the X1 crystal damaged ?
has it ever worked ?
what did you do before it stopped
how long have you had it
what have you done with it

you need to provide more info than that

Re: Raspberry turns on, hot CPU, ethernet and USB not workin

Posted: Mon Dec 16, 2013 11:14 pm
by emmaanuel
RaTTuS wrote: how hot ?
is the X1 crystal damaged ?
has it ever worked ?
what did you do before it stopped
how long have you had it
what have you done with it
3 min after booting, I can feel the CPU hot like if it where in intensive load. I have another RPI and it's not getting hot like this one.
I haven't done anything special before it stop working
I bought it in February 2013
It was working as wifi proxy for several month in a dry and tempered room.

Re: Raspberry turns on, hot CPU, ethernet and USB not workin

Posted: Thu Mar 27, 2014 4:44 am
by Osama
i had the same thing here :
sorry for my english :
i was running the pi and works with the gpio when the pi is powered off !!!!! , i tried to re power it and i saw a red light only .... the i felt the processor and it's tooo hot ... will removed the pi off and put it in the fridge about an hour then let it about 24 hour then powered it again with a AA battery and i saw there is a lit blinking on the OK LED .... then let it about 24 hours again and it's boot :) i felt great but i found the problem still there the processor is too hot and the usb ports doesn't work just the hdmi and when i tried to connect a mouse or keyboard via a hub the pi won't boot ... it seems to me there is a short some where ... am totally new in this and i loved my pi ....
so is there a way to repair this without the need of replacement > ??

Re: Raspberry turns on, hot CPU, ethernet and USB not workin

Posted: Thu Mar 27, 2014 9:31 am
by RaTTuS
Osama wrote:i had the same thing here :
sorry for my english :
i was running the pi and works with the gpio when the pi is powered off !!!!! , i tried to re power it and i saw a red light only .... the i felt the processor and it's tooo hot ... will removed the pi off and put it in the fridge about an hour then let it about 24 hour then powered it again with a AA battery and i saw there is a lit blinking on the OK LED .... then let it about 24 hours again and it's boot :) i felt great but i found the problem still there the processor is too hot and the usb ports doesn't work just the hdmi and when i tried to connect a mouse or keyboard via a hub the pi won't boot ... it seems to me there is a short some where ... am totally new in this and i loved my pi ....
so is there a way to repair this without the need of replacement > ??
what where you doing with the GPIO ?

Re: Raspberry turns on, hot CPU, ethernet and USB not workin

Posted: Thu Mar 27, 2014 10:15 am
by Osama
i was working to make a Pi RC Car using L293D H-bridge module i did it correct but i saw the motors is getting slow when controlling them in the same time . so i thought to increase the voltage. I was using a four 1.5V batteries so i got with 2 ones more and connect them all in parallel and then by fault connect the positive into pin 6 in the pi and the negative in pin 8 in the h-bridge module and then happened what happened .



Now the pi is booting put the processor getting very hot quickly and then the pi restart , restart . restart .

Re: Raspberry turns on, hot CPU, ethernet and USB not workin

Posted: Thu Mar 27, 2014 10:55 am
by GTR2Fan
Powering a Pi straight from a stack of 4x AA batteries is a very bad idea. Four fresh dry cells will initially give you around 6V. Four fully charged NiMH cells may give you around 5.6 to 5.8V. Both are well above the maximum recommended supply voltage of 5.25V and may kill a Pi.

Re: Raspberry turns on, hot CPU, ethernet and USB not workin

Posted: Thu Mar 27, 2014 11:18 am
by Osama
Thanx GTR2Fan for your replay i know that i use four 1.2V batteries for powering the pi and 9V for powering the motors .... i don't know about electrics but i think when i connect the wrong wires of the battery i made an overvoltage to the pi so the processor is getting hot because of a short happened in some where . i don't have any tools to begin doing checking or something like that .i read about voltage regulators so if there is a damage of one of those could the pi running ?

how could i check them ?
how could replace them ?