TroubleShooting for RB450Gr2v3
No power, blue LED doesnt shine
NOT OK
Change faulty diode
D802
OK
Check diode D802
NOT OK
NOT OK
Check PNP transistor
Q802, D804
OK
Check Zener diode D803
NOT OK
OK
Check N-channel Dual
MOSFET Q801
Change faulty MOSFET
Q801
NOT OK
Change faulty PWM
controller U803
OK
Check PWM controller U803
Check resistor R819. It is
resistance value should be
10 Ohm
NOT OK
Change faulty resistor
R819
Problem still appears
The board is unrepairable
PoE doesnt work
NOT OK
OK
Check D805, D806
Change faulty connector J504
Change faulty D805, D806
Change faulty
components
Doesnt boot, green and blue LEDs is shine
NOT OK
Check ferrite beads
FB801, FB806.
It resistance should be
less than 1Ohm
OK
Change faulty DC-DC Step-Down
converter U805
NOT OK
Check 2.5V output, for
example on C849 pins
OK
Change faulty FB801,
FB806
Check ferrite bead
OK
FB802. It resistance
should be less than 1Ohm
Check 0Ohm
resistor on FB803
OK
NOT OK
Check CPU core 1.2V
output, for example on C853
No 0Ohm
NOT OK
Change faulty FB802
Change faulty
resistor
NOT OK
Check 40MHz clock on
oscillator Y301 pin#3
Change faulty Y301
Problem still appears
The board is unrepairable
OK
Change faulty DC-DC
Step-Down converter U806
Ethernet1 doesnt work
NO 75Ohm
Check resistors R563-R566. It is
resistance should be 75Ohm
OK
Change faulty resistors
NOT OK
Change faulty diode array
OK
Check voltage drop on D507, D508
pin#1 and GROUND. It should be in
the range from 0.23V up to 0.3V
measured in diode mode (hold
positive wire on the ground and
COM wire to D507 pin#1)
NOT OK
Change faulty ferrite bead
FB501
OK
Check ferrite bead FB501. It is
resistance should be less than 1 Ohm
OK
Change faulty TR501
NOT OK
Check Ethernet clock 25MHz on
crystal Y501 pin#1
OK
Change faulty crystal Y501
NOT OK
Check PNP transistor
Q601
Problem still appears
NOT OK
Check 1.1V output, for example on
C619 pins
Change faulty PNP
transistor Q601
The board is unrepairable
OK
Change faulty
Ethernet Switch U501
Ethernet2-5 doesnt work
NOT OK
Change faulty connector
OK
Check termination resistance between
Tx and Rx lines in the each Ethernet
connector (J501, J502, J503, J505). The
resistance should be 150 Ohm +/- 2%
Check voltage drop on D501, D502 (for
NOT OK
J501), D503, D504 (for J502), D505, D506
(for J503), D509, D510 (for J505) pin#1 and
GROUND. It should be in the range from
0.23V up to 0.3V measured in diode mode
OK
Change faulty diode array
NOT OK
Change faulty ferrite beads
OK
Check ferrite beads FB502, FB503,
FB504, FB505. It resistance should
be less than 1 Ohm
NOT OK
Check Ethernet clock 25MHz on
crystal Y501 pin#1
OK
Change faulty crystal Y501
NOT OK
Check PNP transistor
Q601
Problem still appears
NOT OK
Check 1.1V output, for
example on C619 pins
Change faulty PNP
transistor Q601
The board is unrepairable
OK
Change faulty
Ethernet Switch U501
Reference
number
Part Number
Manufacturer
Description
D501-D505
AOZ8000CIL
Alpha & Omega
IC TVS ARRAY LOW-CAP
SOT23-6
D802
SR26-GP
SINYORK CO., LTD.
Diode (Rohs compliant)
D803
BZX84C10/SOT23-GP
SINYORK CO., LTD.
Zener Diode BZX84C10 SOT23
D804
BZX84-B27,215
NXP Semiconductors
BZX84-B27, SOT23-A, 27V+/2%, 0.35W
D805, D806
DF02SA-E3/77
Vishay Intertechnology,
Inc.
Bridge Rectifier, 1A 200V, DFS
FB501-FB505
BLM15AG121SN1D
FB801, FB802
BLM18PG331SN1D
FB803
RC0603JR-070RL
FB806
BLM18SG121TN1D
J501, J502, J503,
J505
RB1-216BAK1A
J504
8108-B114
R819
ERJ-2RKF10R0X
R563-R566
RC0603FR-0775RL
Yageo Corporation
Resistor 0603 75,0R 1% 0,1W
Q601
STD888T4
STMICROELECTRONICS
A. P .
Medium Current, High
Performance, Low Voltage PNP
Transistor
Q801
AO4441
Alpha & Omega
Q802
BC856B,215
Philips AG
TR501
G2414SG
Mentech Electronics
Co.,Ltd.
P-Ch MOSFET -60V -4A
100mOhm SO-8
Small Sign PNP 250mW SOT-23
Transistor (RoHS Compliant)
10/100/1000 Ethernet
transformer, SMD
U501
AR8316-AK1E
Atheros Technology Ltd.
6-port GbE Switch
U803
RT9206PS
U805, U806
RT8011APQW
Y301
NAOD40.000-C3C
Y501
NXE25.000AC20FAHF
Ferr Chip Beads 120 Om
500mA, 0402, FB120
Ferr Chip Beads 330 Om
Murata manufacturing Co.
1200mA, 0603
Resistor 5%, 0OHM 1/10W,
Yageo Corporation
200ppm, 0603
Ferr Chip Beads 120Ohm, 3.0A,
Murata manufacturing Co.
0603
RJ45 Ethernet connector 10/
U.D. Electronic Corp.
100/1000 , LEDs(G/Y), without
springs
RJ45 with LEDs (G/Y) Tab
Powerway Electronics Co.,
down,pre-soldered shielding
LTD.
pins
Resistor R10, 1%, 1/16W, 50V,
Panasonic
0402
Murata manufacturing Co.
Richtek Technology
Corporation
Richtek Technology
Corporation
NSK Jenjaan Quartek
Corporation
NSK Jenjaan Quartek
Corporation
Power Controller SOP-16
DC-DC Step down converter,
WDFN-8E
40MHz 3.3V Oscillator 30ppm
25Mhz Crystal, RoHS
When you order components for repairing router boards from our
sales, please, write components reference number not a part number
RB450Gr2v3 Reference picture
RB450Gr2v3 Reference picture
RB450Gr2v3 Reference picture
