Gracias a todos por responder.
He creado el "/var/log/journal" con el touch, a ver si ahora me deja algo.
No existe ningun patron (que yo sepa) para los reinicios.
Sobre la temperatura, lo tendre en cuenta, de momento tengo esto:
# sensors
coretemp-isa-0000
Adapter: ISA adapter
Core 0: +57.0°C (high = +80.0°C, crit = +100.0°C)
Core 1: +57.0°C (high = +80.0°C, crit = +100.0°C)
Core 2: +54.0°C (high = +80.0°C, crit = +100.0°C)
Core 3: +54.0°C (high = +80.0°C, crit = +100.0°C)
it8718-isa-0290
Adapter: ISA adapter
in0: +1.14 V (min = +0.00 V, max = +4.08 V)
in1: +1.90 V (min = +0.00 V, max = +4.08 V)
in2: +3.33 V (min = +0.00 V, max = +4.08 V)
+5V: +2.91 V (min = +0.00 V, max = +4.08 V)
in4: +0.46 V (min = +0.00 V, max = +4.08 V)
in5: +0.00 V (min = +0.00 V, max = +4.08 V) ALARM
in6: +1.20 V (min = +0.00 V, max = +4.08 V)
in7: +3.14 V (min = +0.00 V, max = +4.08 V)
Vbat: +3.22 V
fan1: 1704 RPM (min = 10 RPM)
fan2: 0 RPM (min = 0 RPM)
fan3: 0 RPM (min = 0 RPM)
fan4: 2311 RPM (min = 0 RPM)
temp1: +78.0°C (low = +127.0°C, high = +127.0°C) sensor = thermistor
temp2: +32.0°C (low = +127.0°C, high = +70.0°C) sensor = thermal diode
temp3: -2.0°C (low = +127.0°C, high = +127.0°C) sensor = thermistor
cpu0_vid: +1.150 V
intrusion0: ALARM
nouveau-pci-0100
Adapter: PCI adapter
fan1: 0 RPM
temp1: +57.0°C (high = +95.0°C, hyst = +3.0°C)
(crit = +105.0°C, hyst = +5.0°C)
(emerg = +135.0°C, hyst = +5.0°C)
Gracias y hasta pronto.
Saludos.
--
Josu Lazkano