MikroTik RB433r3 Operating instructions

TroubleShooting for RB433r3, RB433Ur2
These repair instructions are for NON WARRANTY
repairs onl !
No power, blue LED isn’t lit
Please make visual inspection for signs of corrosion or
mechanical damages before starting.
Check Schottky diode D802 Change faulty diode D802
NOT OK
OK
Check Zener diode D804
Change faulty components
Check PNP transistor Q802 and
Zener diode D80
OK
OK
NOT OK
Check P-channel MOSFET
Q801
NOT OK
Change faulty P-channel
MOSFET Q801
OK
Check R819 resistor resistance.
It should be 10 Ohm
NO 10 Ohm
Change faulty resistor
R819
OK
Check PWM controller U80 .
On the pin#1 should be 4.4-
5.0V
NOT OK
Change faulty PWM
controller U80
OK
Check N-channel MOSFET’s
Q806, Q808
NOT OK
Change faulty MOSFET’s
Check short circuit on 1.8V,
for example, on C612 pins
OK
Short circuit
Unsolder Ethernet Switch U601
and check 1.8V for short circuit
OK
Change faulty Ethernet
Switch U601
The board is unrepairable
Problem still
appears

Doesn’t boot, green and blue LEDs are lit
Check 2.5V output, for
example, on C841 pins
NOT OK
Change faulty N-channel
MOSFET Q807
NOT OK
Check voltage on PWM controller
pin#7 (PGOOD). It voltage should
be . V
NO 3.3V
OK
Check PWM controller
U80
Check resistor R 07
resistance. It resistance
should be 68KOhm.
OK
OK
Check 40.000MHz clock on oscillator
Y 01 pin#
Change faulty oscillator
Y 01
NOT OK
The board is unrepairable
Problem still
appears
OK
Change faulty RAM U201, U202
Check 1.2V CPU core output, for
example, on C848 pins
NO 1.2V
Change faulty ferrite bead
FB801
Check Step Down DC-DC
convector U806
Change faulty Step Down
convector U806
OK
OK
NOT OK
NOT OK
Check ferrite bead FB801. It
resistance should be less than
1 Ohm
PoE doesn’t work
Check Schottky diode
D801
NOT OK
Change faulty diode
D801
OK
Check Ethernet
connector J601
NOT OK
Change faulty
connector J601
The board is unrepairable
Problem still
appears
Check N-channel MOSFET
Q807

Ethernet doesn’t work
Check termination resistance between Tx and
Rx lines in the each Ethernet connector J601,
J602, J60 . It should be 150 Ohm +/-2%
Change faulty connectors
Check voltage drop between D601, D602 or
D60 pin#1 and Ground. This value should
be in the range from 0.4 – 0.5V measured
in diode mode (hold “positive” wire on the
ground and “COM” wire to D601 pin#1)
NOT OK
NOT OK
OKOK
Change faulty Ethernet
Switch U601
Check ferrite beads FB602 (for J601),
FB604 (for J602), FB60 (for J60 ). It
resistance should be less than 1 Ohm
Change faulty ferrite beads
NOT OK
OK
Check 1.8V output, for example, on
PNP transistor Q601 pins
No 1.8V
Check Q601 transistor
NOT OK
Change faulty Q601
OK
Change faulty U601
OK
Check 25.000MHz clock on crystal
Y601
NO 25.000 MHz
Change faulty Y601
Problem still appears
The board is unrepairable

When ou order components for repairing boards from our sales, please,
write components reference number not a part number
Reference
number
Part Number Manufacturer Description
J601, J602, J603 ARA-1DKK-G565-B Super Link Electronics
Co., Ltd.
RJ45 10/100 with LEDs and
direct POE output,pre-soldered
shielding pins
D801, D802 FM2100/SMA-GP SINYORK CO., LTD. Diode Schottk FM2100
Vf=0.85V Vr=100V If=2A SMA
Q601 STD888T4 STMICROELECTRONICS
Medium Current, High Performance,
Low Voltage PNP Transistor
D601, D602, D603 AOZ8000CIL Alpha & Omega IC TVS ARRAY LOW-CAP
SOT23-6
D804 BZX84-B27,215 NXP Semiconductors Diode Zener BZX84B 27V 2%
350mW SOT23
FB602, FB603, FB604 BLM15AG121SN1D Murata manufacturing Co. Ferr Chip Beads 120 Om
500mA, 0402, FB120
D803 BZX84C10/SOT23-GP SINYORK CO., LTD. Diode Zener BZX84C 10V 6%
410mW SOT23
R307 RC0402FR-0768KL Yageo Corporation
Resistor 68k 1% 0402
Q807 AOD480 Alpha & Omega
N-Ch MOSFET 30V 25A 23mOhm
DPAK
Q802 BC856B,215 Philips AG
Small Sign PNP 250mW SOT-23
Transistor
Q801 AO4441
Alpha & Omega P-Ch MOSFET -60V -4A 100mOhm
SO-8
FB801 BLM18PG331SN1D Murata manufacturing Co. Ferr Chip Beads 330 Om
1200mA, 0603
Q806, Q808 AO4484 Alpha & Omega
N-Ch MOSFET 40V 10A 10mOhm
SO-8
R819 ERJ-2RKF10R0X Panasonic
Resistor 10R 1% 0402
U601 (for RB433r3) IP175DLF IC Plus Corp. 5Port 10/100 Ethernet Integrated
Switch
U806 RT8010APQW Richtek Technolog
Corporation
High Efficienc PWM Step-
Down DC/DC Converter
U803 RT9206PS Richtek Technolog
Corporation Power Controller SOP-16
Y301 NAOD40.000-C3C NSK Jenjaan Quartek
Corporation 40MHz 3.3V Oscillator 30ppm
Y601 NXE25.000AC20F-AHF NSK Jenjaan Quartek
Corporation 25Mhz Cr stal
U201, U202 NT5DS16M16CS-5T NANYA TECHNOLOGY
CORPORATION
DDR SDRAM 256Mbit DDR400 16M
x 16bit TSOP-66 RoHS
U601 (for RB433Ur2) IP175CLF IC Plus Corp. 5 Port 10/100 Switch with MII

RB433r3 Reference picture

RB433r3 Reference picture

RB433r3 Output Voltage picture