Ethernet ports 2(J501), 3(J505), 4(J503), 5(J502)
do not work, drops ping packets
The board is unrepairable
Problem
still appears
Change faulty connectors
Check 1.0V output,
for example on C619
NO 1.0V
Change faulty transistor
Change faulty ferrite beads
Check voltage drop between diode arrays D501-D506,
D509, D510 pin#1 and Ground. This value should be in the
range from 0.21V to 0.26V measured in diode mode (hold
“positive” wire on the Ground and “COM” wire to D501
pin#1)
Change faulty diode arrays and
6-port GbE Switch U501
NOT OK
O
K
Check 1.5V output,
for example on C841 pins
Change faulty ferrite beads
NO 1.5V
O
K
Check ferrite beads FB502-FB505 resistance.
It should be less than 1 Ohm
Change faulty ferrite bead
NOT OK
O
K
Check termination resistance between Tx
and Rx lines in the each Ethernet connector.
It should be 150 Ohm +/- 2%
NOT OK
O
K
Check ferrite beads FB804, FB805
resistance. It should be less than 1 Ohm
N
O
T
O
K
OK
Change faulty DC-DC Step-Down
converter U807
Check PNP transistor
Q601
Check ferrite beads FB601,
FB602, FB604-FB607 resistance.
It should be less than 1 Ohm
Change faulty 6-port
GbE switch U501
Check 25MHz clock on
R541 pins
NOT OK
Change faulty Network processor
U1
OK
OK
N
O
T
O
K
N
O
T
O
K
O
K
Summary of Contents for RB450G
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