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Raspberry Pi 3 is getting hot even kept idle

Posted: Tue Nov 12, 2019 10:24 am
by Lucifer22334
Hi all,

My Raspberry PI 3 is getting hot even I am not running any program or doing the thing on it. Just booted it up and nothing. The temperature sign displayed on the monitor and temperature inside this indicator blinks and makes it to the top when I run simple LED blinking program. The processor chip is not getting heat up so much just normal heating, it's backside part which was not getting heat up before. The circled part is where it gets heated up. Any idea why this is happening what can I do to prevent it.

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Tue Nov 12, 2019 11:46 am
by drgeoff
The circled area is the underside of the Broadcom SoC, the CPU and GPU.

Have you been attaching things to the GPIO header? Do you use the RPi without a case such that it could have come in contact with anything metallic?

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Tue Nov 12, 2019 11:54 am
by Lewis-H
The Raspberry Pi 3 can overheat and due to its lack of a fan, it automatically shuts down or disables overclocking to prevent severe hardware damage. Whenever the temperature goes higher than 85°F, one of these two things will happen. The Pi3 has been reported to generate more heat than previous models, but the heatsink is not required. You can install it for some extra thermal protection, but the Pi will throttle the clock speed to maintain a safe temperature.

Regards,
Lewis

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Tue Nov 12, 2019 12:14 pm
by Lucifer22334
drgeoff wrote:
Tue Nov 12, 2019 11:46 am
The circled area is the underside of the Broadcom SoC, the CPU and GPU.

Have you been attaching things to the GPIO header? Do you use the RPi without a case such that it could have come in contact with anything metallic?
No, I am using Pi in its case only. And I had attached a Simple RFID card reader and LCD display and DHT11 sensors recently. But nothing Metallic was touched.

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Tue Nov 12, 2019 12:18 pm
by Lucifer22334
Lewis-H wrote:
Tue Nov 12, 2019 11:54 am
The Raspberry Pi 3 can overheat and due to its lack of a fan, it automatically shuts down or disables overclocking to prevent severe hardware damage. Whenever the temperature goes higher than 85°F, one of these two things will happen. The Pi3 has been reported to generate more heat than previous models, but the heatsink is not required. You can install it for some extra thermal protection, but the Pi will throttle the clock speed to maintain a safe temperature.

Regards,
Lewis
I had already placed the Heatsink which came with the raspberry pi but still with this it was getting so much heat. So I have attached Pi fan right now and it is now showing heating symbol.

But I am thinking this should not be happening right with a pi if it's in idle case. I am searching for a solution because I need to implement Face recognition and identification with Open CV on it and when implementing this it will get heat up a little.

If I can do anything else to prevent this please suggest me I don't want my pi to get burned or damage.

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Tue Nov 12, 2019 1:17 pm
by mahjongg
Try powering it up without having an SD-card inserted, so it absolutely doesn't boot, and doesn't run any code.

If it still heats up, then there is something wrong inside the main chip, for example damage caused by a latch-up event triggered by (momentarily) applying more than about 4Volt (or a negative voltage) on a GPIO pin, or by an ESD event (electrostatic discharge).
Latch-up damage causes burned out transistors, which heat up, and burn other nearby transistors, its irreparable.

Its the first rule you need to know. PI's ARE NOT 5V TOLERANT!

https://en.wikipedia.org/wiki/Latch-up

other things that can damage your PI you can read about here: https://www.raspberrypi.org/forums/view ... 1#p1467093

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Tue Nov 12, 2019 5:06 pm
by emma1997
Thank you for that link mahjongg. I don't know how I missed it all this time. Specially since it's listed as sticky but apparently not in an area I've ever visited.

For CMOS devices there is often specified a typical latchup current limit (usually microamps) and also maximum forward current for clamp diodes (usually milliamps). Is there a document anywhere or other source with actual numbers for the Pi?

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Tue Nov 12, 2019 5:15 pm
by rpdom
The Pi does not have clamp diodes. The current limit for the GPIOs varies depending on the drive settings, but generally it should be no more than 16mA for an individual GPIO or 50mA (I think it was) total.

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Tue Nov 12, 2019 5:57 pm
by emma1997
I was asking about protection diode maximum forward bias not GPIO drive current. However if there are no diodes at all that does, if true, explain a lot of strange readings by myself and others on the internet regarding input voltage tolerance.

Mostly I was wondering if this is documented anywhere and not just hearsay. How did you find this info?

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Wed Nov 13, 2019 5:46 am
by Lucifer22334
mahjongg wrote:
Tue Nov 12, 2019 1:17 pm
Try powering it up without having an SD-card inserted, so it absolutely doesn't boot, and doesn't run any code.

If it still heats up, then there is something wrong inside the main chip, for example damage caused by a latch-up event triggered by (momentarily) applying more than about 4Volt (or a negative voltage) on a GPIO pin, or by an ESD event (electrostatic discharge).
Latch-up damage causes burned out transistors, which heat up, and burn other nearby transistors, its irreparable.

Its the first rule you need to know. PI's ARE NOT 5V TOLERANT!

https://en.wikipedia.org/wiki/Latch-up

other things that can damage your PI you can read about here: https://www.raspberrypi.org/forums/view ... 1#p1467093
I tried without SD card and it was not heating up. So is there a problem in OS?

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Thu Nov 14, 2019 5:51 am
by Lucifer22334
Does anyone have any idea?

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Thu Nov 14, 2019 6:50 am
by B.Goode
Lucifer22334 wrote:
Thu Nov 14, 2019 5:51 am
Does anyone have any idea?
From your initial question:
My Raspberry PI 3 is getting hot even I am not running any program or doing the thing on it. Just booted it up and nothing. The temperature sign displayed on the monitor and temperature inside this indicator blinks and makes it to the top when I run simple LED blinking program.

Which statement is correct?

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Thu Nov 14, 2019 7:29 am
by dustnbone
Run top from the command line and see if the CPU is indeed idling. If there's no heat with no SD card it almost has to involve software.

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Thu Nov 14, 2019 7:54 am
by Lucifer22334
B.Goode wrote:
Thu Nov 14, 2019 6:50 am
Lucifer22334 wrote:
Thu Nov 14, 2019 5:51 am
Does anyone have any idea?
From your initial question:
My Raspberry PI 3 is getting hot even I am not running any program or doing the thing on it. Just booted it up and nothing. The temperature sign displayed on the monitor and temperature inside this indicator blinks and makes it to the top when I run a simple LED blinking program.

Which statement is correct?
On Start, I don't do anything just the desktop is showed. The CPU usage is between 0-12 and after some time like 2-3 min it starts getting heat up and shows the thermometer sign.

Then I reboot it and again try. One time when it is not heating up I run a simple LED blink program or I even open up a VLC player or any application that starts to heat up.

Both of my statements are true.

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Thu Nov 14, 2019 7:55 am
by Lucifer22334
dustnbone wrote:
Thu Nov 14, 2019 7:29 am
Run top from the command line and see if the CPU is indeed idling. If there's no heat with no SD card it almost has to involve software.
what do you mean by"Run top from the command line"?

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Thu Nov 14, 2019 8:28 am
by rpdom
Lucifer22334 wrote:
Thu Nov 14, 2019 7:55 am
what do you mean by"Run top from the command line"?
It means go to the command line (Terminal) and type in the command "top", which will give you a screen like this:

Code: Select all

top - 08:26:51 up 12 days, 17:17,  2 users,  load average: 0.06, 0.02, 0.00
Tasks:  76 total,   1 running,  75 sleeping,   0 stopped,   0 zombie
%Cpu(s):  0.7 us,  1.0 sy,  0.0 ni, 98.3 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
MiB Mem :    432.7 total,     26.4 free,     37.3 used,    369.0 buff/cache
MiB Swap:    100.0 total,     97.0 free,      3.0 used.    320.9 avail Mem 

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND                      
14930 pi        20   0   10172   2872   2440 R   1.3   0.6   0:00.30 top                          
10170 root      20   0       0      0      0 I   0.3   0.0   0:00.59 kworker/u2:0-flush-179:0     
14817 root      20   0       0      0      0 I   0.3   0.0   0:00.40 kworker/0:1-events_power_ef+ 
    1 root      20   0   34648   5808   4584 S   0.0   1.3   1:11.76 systemd                      
    2 root      20   0       0      0      0 S   0.0   0.0   0:00.81 kthreadd                     
    6 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 mm_percpu_wq                 
    7 root      20   0       0      0      0 S   0.0   0.0   5:07.77 ksoftirqd/0                  
    8 root      20   0       0      0      0 S   0.0   0.0   0:00.01 kdevtmpfs                    
    9 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 netns                        
   11 root      20   0       0      0      0 S   0.0   0.0   0:00.90 khungtaskd                   
   12 root      20   0       0      0      0 S   0.0   0.0   0:00.00 oom_reaper                   
   13 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 writeback                    
   14 root      20   0       0      0      0 S   0.0   0.0   0:00.00 kcompactd0                   
   15 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 crypto                       
   16 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kblockd                      
   17 root      rt   0       0      0      0 S   0.0   0.0   0:00.00 watchdogd                    
   18 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 rpciod                       
   20 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 xprtiod                      
that will keep refreshing until you press "q". It'll show how busy your system is.

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Thu Nov 14, 2019 11:18 am
by Lucifer22334
rpdom wrote:
Thu Nov 14, 2019 8:28 am
Lucifer22334 wrote:
Thu Nov 14, 2019 7:55 am
what do you mean by"Run top from the command line"?
It means go to the command line (Terminal) and type in the command "top", which will give you a screen like this:

Code: Select all

top - 08:26:51 up 12 days, 17:17,  2 users,  load average: 0.06, 0.02, 0.00
Tasks:  76 total,   1 running,  75 sleeping,   0 stopped,   0 zombie
%Cpu(s):  0.7 us,  1.0 sy,  0.0 ni, 98.3 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
MiB Mem :    432.7 total,     26.4 free,     37.3 used,    369.0 buff/cache
MiB Swap:    100.0 total,     97.0 free,      3.0 used.    320.9 avail Mem 

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND                      
14930 pi        20   0   10172   2872   2440 R   1.3   0.6   0:00.30 top                          
10170 root      20   0       0      0      0 I   0.3   0.0   0:00.59 kworker/u2:0-flush-179:0     
14817 root      20   0       0      0      0 I   0.3   0.0   0:00.40 kworker/0:1-events_power_ef+ 
    1 root      20   0   34648   5808   4584 S   0.0   1.3   1:11.76 systemd                      
    2 root      20   0       0      0      0 S   0.0   0.0   0:00.81 kthreadd                     
    6 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 mm_percpu_wq                 
    7 root      20   0       0      0      0 S   0.0   0.0   5:07.77 ksoftirqd/0                  
    8 root      20   0       0      0      0 S   0.0   0.0   0:00.01 kdevtmpfs                    
    9 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 netns                        
   11 root      20   0       0      0      0 S   0.0   0.0   0:00.90 khungtaskd                   
   12 root      20   0       0      0      0 S   0.0   0.0   0:00.00 oom_reaper                   
   13 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 writeback                    
   14 root      20   0       0      0      0 S   0.0   0.0   0:00.00 kcompactd0                   
   15 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 crypto                       
   16 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kblockd                      
   17 root      rt   0       0      0      0 S   0.0   0.0   0:00.00 watchdogd                    
   18 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 rpciod                       
   20 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 xprtiod                      
that will keep refreshing until you press "q". It'll show how busy your system is.
oh...sorry for the late response I have reflashed stretch OS on Raspberry Pi. And now I am going to test it.
Thank you very much for your help. I learned a lot and if after testing I am getting same error I will post here.

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Thu Nov 14, 2019 11:39 am
by RaTTuS
use buster

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Thu Nov 14, 2019 12:49 pm
by Lucifer22334
RaTTuS wrote:
Thu Nov 14, 2019 11:39 am
use buster
Will Open CV Work on Buster and Raspberry pi 3 is compatible with it?

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Thu Nov 14, 2019 1:18 pm
by Imperf3kt
Is this Pi inside a small plastic case with little to no ventilation?

Re: Raspberry Pi 3 is getting hot even kept idle

Posted: Fri Nov 15, 2019 5:21 am
by Lucifer22334
Imperf3kt wrote:
Thu Nov 14, 2019 1:18 pm
Is this Pi inside a small plastic case with little to no ventilation?
It is not. It is in open space on a wooden platform. So it has sufficient Air.