Orange Pi Zero Plus 2 Temperature issue

[maracuja]

I have perfectly equal Orange Pi Zero Plus 2 H3 boards in their original case - booting from eMMC.

Test conditions are: WiFi Hotspot enabled, HDMI off, CPU idle, CPU governor: performance, CPU freq. 240MHz - 1.1 GHz, kernel 4.14.84

Xiaomi Mi5 Charger as psu, 2.4A usb cable

 

armbianmonitor gives me a temp of ~50°C on one board (idle@1.1GHz)

and a temp of 65°C on the other board (same conditions, CPU starts throttling here to ~960 MHz).

 

The temp gets so high, that after an apt-get update/upgrade and reboot the opizero plus2 would not boot with an error msg that the temp is too high.

The temp seems to be correct more or less, since also the power consumption is significantly higher. While the 50°C board draws ~1.5W, the 65°C board draws ~1.8W.

 

I have no explanation for this...

[maracuja]

I have removed the stickers from the board

and placed the antenna differently so the metal piece would not touch any chip.

 

But still... 1.8W current draw.

 

I have tested a third board. All boards have the same configuration, same revision 1.0, and a usb extension board attached.

One board draws 1.3-1.4W, one draws 1.4-1.5W, and the strange one draws 1.8W.

The 2 "normal" boards reach ~45°C after 40 minutes (temp. seems stable).

 

The strange board reaches

~53°C after 11 minutes,

~57°C after 18 minutes

~60°C after 26 minutes 

~61°C after 40 minutes