MikroTik RB450G, Руководство по устранению неисправностей

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Ethernet port1 (J504) does not work,
drop ping packets
The board is unrepairable
Problem
still appears
Check 1.0V output,
for example on C619
NO 1.0V
Change faulty transistor Change faulty ferrite beads
Check voltage drop between diode arrays D507, D508
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 D507 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 bead FB501 resistance.
It should be less than 1 Ohm
Change faulty ferrite bead
NOT OK
O
K
Change faulty connector
Check transformer
TR501
NOT OK
O
K
Check resistors R563-R566 resistance.
It should be 75 Ohm +/-1%
O
K
Change faulty resistors
NOT OK
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