Laptop freezes and reboots

mithrandir_fool

New Member
Hi everyone, newbie here.

I have a problem that has been occurring for one month now:
once or twice every other day, my laptop freezes, meaning that the screen starts flickering, and then the laptop reboots. The issue sometimes manifests itself by trying to boot several times, but failing. Sometimes I have to hard reboot after the screen freezes.
It usually happened when I tried to move the laptop from below, or when I moved the screen after some time.

This issue is 'scientifically' happening also when I am trying to train a machine learning model with FastText on a coprus of 230MB, indipendently from using 1 thread or the default settings. Three times out of three, after some time (usually around 20% of the training), the malevolent event happens.

I kept track of the CPU temperatures during the last training, with core-0 being at 65°C and core-1 at 57°C (never above 69°C).

My laptop is a Lenovo ideapad 310
Intel Core i5-7200U [email protected] x 4
12GB RAM
Intel HD Graphics 620 (Kaby Lake GT2) ---> I have also a dedicated NVIDIA GeForce 920M, 2GB

The laptop is 2-years old, the battery is not good (it probably lasts ~1 hour max), the charger is not the original Lenovo one, as it stopped working; I bought a KFD charger that suited the voltage.
I opened the laptop a couple of days ago to remove some dust from the case and the fan.

Dual boot with:
Windows 10
Ubuntu 18.04.3 LTS

98% of the time I use Ubuntu.

From /var/log/syslog, this is the last set of messages before I had to hard reboot:

Oct 2 15:44:50 MatteoLenovo wpa_supplicant[978]: wlp2s0: CTRL-EVENT-SIGNAL-CHANGE above=1 signal=-61 noise=-109 txrate=1000
Oct 2 15:48:01 MatteoLenovo wpa_supplicant[978]: wlp2s0: WPA: Group rekeying completed with 24:01:c7:db:01:74 [GTK=CCMP]
Oct 2 15:48:33 MatteoLenovo wpa_supplicant[978]: wlp2s0: CTRL-EVENT-SIGNAL-CHANGE above=0 signal=-66 noise=-109 txrate=1000
Oct 2 15:49:37 MatteoLenovo wpa_supplicant[978]: wlp2s0: CTRL-EVENT-SIGNAL-CHANGE above=1 signal=-61 noise=-109 txrate=1000
Oct 2 15:51:28 MatteoLenovo wpa_supplicant[978]: wlp2s0: CTRL-EVENT-SIGNAL-CHANGE above=0 signal=-65 noise=-109 txrate=1000
Oct 2 15:53:51 MatteoLenovo wpa_supplicant[978]: wlp2s0: CTRL-EVENT-SIGNAL-CHANGE above=1 signal=-60 noise=-109 txrate=1000
Oct 2 16:14:56 MatteoLenovo systemd[1]: Starting Flush Journal to Persistent Storage...

It happened at 15:54.

Do you have any advice on such a matter? Can I post any other log?

Thank you very much for your time and your help :)

Cheers
 


mithrandir_fool

New Member
I reply to my own thread:

Today we opened the laptop and checked the thermal paste, the GPU itself, faulty connections, and the RAM.
It turned out that what caused the laptop to freeze and reboot (or shut down) was the removable RAM bank. At least, without it, the laptop didnt show (and is not showing) any misbehavior.
We checked the weld joint at the microscope (thanks to the meccatronic lab technicians) and we found no faulty joint.
We will try with another DDR-4 bank tomorrow, to check whether it could be a problem of momentary pressure when moved or if it was that specific faulty RAM bank.

I am confident to say it was no conflict with drivers or similia.
 

poorguy

Well-Known Member
I would reinstall the ram module and give it a try it's possible that the ram module just needs to be re-seated.
 

LeoR

New Member
The laptop is 2-years old, the battery is not good (it probably lasts ~1 hour max), the charger is not the original Lenovo one, as it stopped working; I bought a KFD charger that suited the voltage.
That might be the cause. Did you check that the new charger also has enough power (W) and not just the correct voltage (V)?

If the charger has less power, in combination with an old battery and heavy workloads consuming even more power, it can't keep the required voltage. Result=strange behaviour.
 

mithrandir_fool

New Member
I would reinstall the ram module and give it a try it's possible that the ram module just needs to be re-seated.
Thanks for tips.
It's the first time I read about this, could you share a step-by-step guide or link to a resource about this?

By the way, this morning I tried another DDR4 RAM module and my laptop worked just fine (under intense computational load and under physical pressure).
Instead, I tried my RAM module on a new laptop and it shut down randomly or when trying a burning test.
 

poorguy

Well-Known Member
Thanks for tips.
It's the first time I read about this, could you share a step-by-step guide or link to a resource about this?

By the way, this morning I tried another DDR4 RAM module and my laptop worked just fine (under intense computational load and under physical pressure).
Instead, I tried my RAM module on a new laptop and it shut down randomly or when trying a burning test.
I've solved many problems on desktops and laptops by re-seating memory modules and graphics cards.

Usually a first step in troubleshooting.

The ultimate test on components under question are to substitute them with known good working components. (process of elimination)

If the ram module fails in a different laptop than obviously it is bad.

Glad you got it solved.
 
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