MikroTik RB433r3 Troubleshooting Manual

TroubleShooting for RB433r3, RB433Ur2
These repair instructions are for NON WARRANTY
Please make visual inspection for signs of corrosion or
Check Schottky diode D802
Check Zener diode D804
Check P-channel MOSFET
Q801
Check R819 resistor resistance.
It should be 10 Ohm
Check PWM controller U803.
On the pin#1 should be 4.4-
5.0V
Check N-channel MOSFET's
Q806, Q808
Check short circuit on 1.8V,
for example, on C612 pins
Problem still
mechanical damages before starting.
No power, blue LED isn't lit
NOT OK
OK
NOT OK
NO 10 Ohm
NOT OK
NOT OK
Short circuit
appears
The board is unrepairable
repairs only!
Change faulty diode D802
Check PNP transistor Q802 and
Zener diode D803
Change faulty P-channel
MOSFET Q801
Change faulty resistor
R819
Change faulty PWM
controller U803
Change faulty MOSFET's
Unsolder Ethernet Switch U601
and check 1.8V for short circuit
Change faulty Ethernet
Switch U601
NOT OK
Change faulty components