221 AC/DC
Ultima modifica/Last Update/Letzte Veraenderung: 23/04/2014 Rev1
pagina 17 di 35
SPIEGAZIONE
The varistor is a blue discs near the ground wire of the
power board. This device is for protecting the board from
input overvoltage. When there is overvoltage they
“explode” causing a short circuit most of the times. If the
extent of the short circuit is very high they become an
open circuit.
To check the PFC of the switching power supply unit,
carry the following measurements with a diode tester:
Should there be a short-circuit on one of these measure-
ments or an “OL” instead of a numeric value, the power
board must be replaced.
P
IC
T
U
R
E
1
Red Probe
Black Probe
Measure
D
S
“OL”
S
D
380
G
S
1.69
S
G
“OL”
G
D
1.69
D
G
“OL”
P
IC
T
U
R
E
2
D S G
