MikroTik RB800r2v5, Troubleshooting Manual

Page: 6 / 12

MiniPCI-Express doesn’t work
NOT OK
Check 1.5V output, for
example on C464
N
O
T
O
K
OK
The board is unrepairable
P
ro
b
le
m
s
s
til
l a
p
p
e
a
rs
FAN doesn’t work
Check 5-7V, for example
on C433 pins
Check Schottky diodes
D28, D29
Check MOSFET’s Q2, Q3
Check TinyLogic invertor
U20
Check ferrite bead
FB11. Ferrite bead
resistance should be
less than 1 Ohm
Change faulty PWM
step down converter
U29
Change faulty FB11
NO 5-7V
O
K
Change faulty D28, D29
Change faulty Q2, Q3
Change faulty U20
O
K
O
K
NOT OK
NOT OK
NOT OK
Check 25MHz clock on
crystal Y3
Change faulty frequency
generator U17
Change faulty FAN Check FAN
N
O
T
O
K
O
K
NO 25MHz