I have a raspberry pi 3B+ model that I bought back in February 2019.
For sometime, I "remember" it was working fine (although I can say from experience - memories can be deceiving).
Then I sort of forgot about it and left it off for a while. Recently, about 2~3 days ago, I resurrected that Raspberry Pi again. And noticed random reboots - for no apparent reason - probably due to all the updates it got after being brought back to life again.
Thankfully, I immediately checked back to the power supply I bought from here and was grateful to find out that my power supply was rated at 2,5A and hence completely suitable to work with the Raspberry Pi.
I also looked into Syslog and found no suspicious (some sort of power-related) messages. (should they be there? Dunno!)
Needless to say the random reboots, did occur, sometimes three~four times immediately one after the other, within a few minutes of each other, or the Pi could go on running for 2 days and then reboot.
I suspected at this stage that it might be a software issue. I reinstalled Raspbian from scratch (no NOOB!) and rebooted. Sadly the problem was back almost immediately.
I installed NOOB and proceeded to install RiscOS. After booting up, it seemed to run snappy (not surprising). No reboots in the 20~30 min that it took me to orient myself with RiscOS and try to find out 'how to shutdown or reboot from within the RiscOS'.
Short of someone hacking into my Pi for no good reason and rebooting it (#paranoid), I "felt" at this stage, this must be a Raspbian kernel issue or some firmware issue of some sort. Tempted to install Kali or Ubuntu (32bit/64bit) or even something more exotic like Gentoo, but being the masochist that I am, I decided to install the full Raspbian OS again - from the NOOB this time. And so I whiled away that whole sunny sunday.
After rebooting the problem seemed to have disappeared. I left the Pi running for 2 days, checking back every evening and finding out that indeed it had been running non stop, until last night, when it had rebooted.
I restarted my "tasks" manually on the Pi (manually on purpose, Cron could've fixed the job but I wanted to find out why the Pi reboots). And just now, as the cat didn't let me sleep, I got up anyways, and checked that the Pi had once again rebooted.
Googled and found out about dmesg and now I see these messages about under voltage there.
... [ 6.328679] random: 7 urandom warning(s) missed due to ratelimiting [ 6.361729] ieee80211 phy1: rt2x00_set_rt: Info - RT chipset 5390, rev 0502 detected [ 6.415268] ieee80211 phy1: rt2x00_set_rf: Info - RF chipset 5370 detected [ 6.484518] ieee80211 phy1: Selected rate control algorithm 'minstrel_ht' [ 6.487084] usbcore: registered new interface driver rt2800usb [ 7.287338] Under-voltage detected! (0x00050005) [ 8.297779] uart-pl011 3f201000.serial: no DMA platform data [ 8.469399] 8021q: 802.1Q VLAN Support v1.8 [ 8.525940] Adding 102396k swap on /var/swap. Priority:-2 extents:1 across:102396k SSFS [ 9.045327] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready [ 9.045370] brcmfmac: brcmf_cfg80211_set_power_mgmt: power save enabled ... ... [ 16.820673] Bluetooth: RFCOMM ver 1.11 [ 1519.024627] brcmfmac: brcmf_run_escan: error (-52) [ 1519.024641] brcmfmac: brcmf_cfg80211_scan: scan error (-52) [ 6530.222765] Voltage normalised (0x00000000) [ 6532.302543] Under-voltage detected! (0x00050005) [ 6536.462131] Voltage normalised (0x00000000) [ 6540.622579] Under-voltage detected! (0x00050005) [18679.342533] brcmfmac: brcmf_run_escan: error (-52) [18679.342547] brcmfmac: brcmf_cfg80211_scan: scan error (-52) ...
Like I said, the power supply is advertised as a 2,5A supply. And I have no external devices connected to the Pi that don't have their own power supply. It is basically running in a headless mode.
So, the question is, time to buy a new charger a.k.a (expand the ever-growing collection of USB chargers lying around the house)?