Selco Genesis 240 TLH, Repair Manual

Page: 43 / 82

Diagnosis procedure 125
10.3)
Fasi diagnostiche (see from fig. 36 to 43 )
G 240 :
(level 1 and 2)
Stage 1 : Remove the upper cover from the machine
Machine disconnected from the mains
Disconnect cables no.22 and no.23 from board 15.14.254 (and insulate the terminals)
By means of a wire, create a short circuit between TP6 and TP3 on board 15.14.254
Checks :
Look for any signs of burning on cards or cables.
yes : go on ; no : look:
- varistor on Card 15.14.233 in good condition
yes : go on ; no : replace varistor
- tracks on printed circuits and other components good on Card 15.14.233
yes : go on ; no : replace damaged Card
- capacitor 12.03.020 (upper part of machine) in perfect condition
yes : go on ; no : replace capacitor 12.03.020
Using a multimeter set at the diode test, check between the points of Card 15.14.233 :
a-b = approximately 0.4V
aa-b = approximately 0.4V
aaa-b = approximately 0.4V
b-a = OPEN
b-aa = OPEN
b-aaa = OPEN
bb-a = approximately 0.4V
bb-aa = approximately 0.4V
bb-aaa = approximately 0.4V
a-bb = OPEN
aa-bb = OPEN
aaa-bb = OPEN
yes : go on ; no : replace the rectifier bridge or board 15.14.233 (according to the results of the following checks)
NOTE : the previous test can be performed with the master switch closed, taking the measurement between the machine
input phases and cables no.22 and no.23. In this case, however, if a negative result is obtained it can depend not only
on the diode bridge but also on the state of the switch contacts or the tracks of the 15.14.233.
Using a multimeter set at the diode test, check between the points of Card 15.14.233 :
c-cc = open circuit ( >= 2V)
cc-c = approximately 0.2V
yes : go on ; no : perform secondary power diodes checking procedure.
Stage 2 : Machine connected to mains.
Disconnect connector CN1 of board 15.14.254
Disconnect connector CN1 of board 15.14.233
Turn on master switch
Checks :
With a tester set to Vac, check that there is a voltage of 400 Vac between points a, aa and aaa of board 15.14.233
(connection to master switch output terminals).
yes : go on ; no : after disconnecting the machine from the mains power supply, check:
- that the current plug is correctly fitted on the power supply cable
- that the power supply cable has not been interrupted
- that the master switch is closed
- that the cables are correctly fitted to the master switch
NOTE : the previous test can be performed taking the measurement between points U, V and W indicated in the figure
but in this case, if a negative result is obtained, it can depend not only on the causes listed above but also on the state
of the tracks of the 15.14.233.