MikroTik RB800r2v5, Руководство по устранению неисправностей

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Ethernet1 doesn’t work, drops ping packets
Check transformer TR1
The board is unrepairable
NOT OK
NOT OK
O
K
Problems still appears
O
K
Check ferrite beads FB4, FB5.
Ferrite beads resistance should
be less than 1 Ohm
OK
Check Ethernet clock 25MHz
on crystal Y4
NO 25MHz
O
K
NOT OK
Check 1.2V output, for example
on C168
Check resistors R152, R153,
R154, R155 resistance. It
should be 75Ohm +/-1%
Change faulty resistors
Change faulty TR1
Change faulty U28
NOT OK
O
K
Change faulty FB4,
FB5
Change faulty Ethernet
PHY U18
Change faulty crystal Y4
Check voltage drop on
D5, D8 pin#1 and ground.
It should be in the range from 0.3V to 0.4V measured
in diode mode (hold “positive” wire on the ground and
“COM” wire to
D5 pin#1) or you can unsolder diode arrays D5, D8
and try to send traffic over Ethernet port. If traffic goes
through port it means that diode arrays was defective
Change faulty D5, D8
NOT OK
O
K
Check ferrite bead FB9. It
is resistance should be
less than 1Ohm
OK
N
O
T
O
K
Change faulty ferrite
bead FB9