ALFIN 160 MF, Service Manual

Page: 18 / 20

161 MF— 161 MTM
Ultima modifica/Last Update: 18/03/2008 Rev0 pagina 15 di 17
EXPLANATION
Input bridge rectifier on power board.
To check the Input bridge rectifier , carry out the following
measurements with a diode tester:
Should there be a short circuit on one of these measurements,
the input bridge rectifier must be replaced.
To check the inverter, carry out the following measurements
with a diode tester:
Should there be a short-circuit on one of these measurements
or an “OL” instead of a numeric value, the power board must
be replaced.
The varistor is a blue discs near the ground wire of the power
board. This device is necessary to protect the board from input
overvoltage. When there is overvoltage it “explode” causing a
short circuit most of the times. If the extent of the short circuit
is very high its becomes an open circuit.
Faston Probe Faston Probe Misura
F+ Red D Black “OL”
F Red D Black >.450
F+ Black D Red “OL”
F Black D Red >.450
P
IC
T
U
R
E
3
F+
D F-
D
G D S
G
D
S
G
D
S
G
D
S
P
IC
T
U
R
E
4
Red Probe Black Probe Measure
S G 0.28
G S 0.6
P
IC
T
U
R
E
5
Varistor