YORK INTERNATIONAL
27
FORM 450.20-N20 (702)
4
MAINTENANCE
SYMPTOM
PROBABLE CAUSE
SOLUTION
Green LED for a single device is
constantly ON.
Transceiver is damaged.
Network voltage levels exceeded.
Transceiver is damaged.
Multiple transceivers damaged.
Short circuit between shield and P3.
Multiple transceivers damaged.
Short circuit between P2 and P3.
Short circuit between shield and P2.
Network voltage levels exceeded.
Ensure LAN cable is wired cor-
rectly.
Disconnect LAN cable with power
ON. If light remains on, replace
LINC.
Measure voltage between P2 and
P3. If greater than 5 VDC, isolate
network devices and determine
cause.
Measure voltage between P2 and
ground/earth and between P3 and
ground/earth. If greater than 12 or
less than -7 VDC, isolate networks
devices and determine cause.
Disconnect LAN cable with power
ON. If light remains on, replace
LINC.
Disconnect LAN devices one at a
time until fault indication disap-
pears. Repair/replace faulty device.
Remove power and disconnect the
LAN cable at both ends. Ensure
resistance between P3 and shield is
infinite. If not, replace cable.
Disconnect LAN devices one at a
time until fault indication disap-
pears. Repair/replace faulty device.
Remove power and disconnect the
LAN cable at both ends. Ensure
resistance between P2 and P3 is
infinite. If not, replace cable.
Remove power and disconnect the
LAN cable at both ends. Ensure
resistance between P2 and shield is
infinite. If not, replace cable.
Measure voltage between P2 and
P3. If greater than 5 VDC, isolate
network devices and determine
cause.
Measure voltage between P2 and
ground/earth and between P3 and
ground/earth. If greater than 12 or
less than -7 VDC, isolate networks
devices and determine cause.
Red and green LEDs for a single
device are constantly ON.
Geen LED on for all network
devices.
Status LEDs are normal but units do
not communicate.
