Ricoh A250 Service Manual page 444

2.6.2 NCU (US)
S u r g e
TIP
Protection
Over-
RING
current
Protection
T1
N o i s e
Filter
T2
Jumpers
Item Description
JP7 These jumpers should be shorted when the machine is connected to a
dry line.
JP8
DB1 Also remove DB1 when the machine is connected to a dry line.
SM
N o i s e C M L
Filter Relay
S u r g e
Protection
Current
S e n s o r
2-23
J P 7
O H D I S W .
D B 1
D C L o o p
J P 8
NCU
Ring
Detection
Circuit
PCBS
TRXD
L-
Transformer
O H D I S W
C M L S W
H o o k 0
H o o k 1
E x R i n g
A891D520.WMF
A250