Client Repair instruction
for
CRS328-24P-4S+RM r2
Published 14.05.2018.
These repair instructions are for NON WARRANTY repairs only!
Please make visual inspection for signs of corrosion
or mechanical damages before starting.
Contents
Disassembling information.................................................................................................3
Routerboard does not power on........................................................................................6
Routerboard does not boot...............................................................................................10
Temperature reading – FAILED / Overheating.................................................................11
One of ethernet ports (1-8) does not work......................................................................12
One of ethernet ports (9-16) does not work....................................................................12
One of ethernet ports (17-24) does not work..................................................................13
One of POE-OUT does not work.......................................................................................13
SFP+ port1 doesn’t work...................................................................................................14
SFP+ port2 doesn’t work...................................................................................................14
SFP+ port3 doesn’t work...................................................................................................15
SFP+ port4 doesn’t work...................................................................................................15
Serial port test failed..........................................................................................................16
Components placement....................................................................................................17
Components list.................................................................................................................21
Picture 1
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Disassembling information
Step 1:
Undo 9 Phillips type screws from the case and remove cover. (screw locations shown in
picture 2,3,4).
Picture 2
Picture 3
Picture 4
Step 2:
Unplug all power connectors from the PSE units. Then undo 6 Phillips type screws as
shown in picture 5. After that carefully pull out the PSE units and unplug both connectors
from the main board. Put the PSE units aside in the same order as in the board to avoid
wrong assembling after repair.
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Picture 5
Step 3:
Disconnect fans and power connector. Undo 9 Phillips type screws (picture 6). Now the
main PCB can be removed.
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Picture 6
Step 4:
Using Phillips type screwdriver for screws and nose pliers for plastic clips, remove both
heat sinks.
Picture 7
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Routerboard does not power on
First of all, check the mains cable and power supply unit. Measure voltage drop between
black and coloured wires for all channels. Voltage between black-yellow should be 26.5 ±
2V, black-red 56 ± 2V, black-blue 24 ± 2V.
Diagnose potential problem area
Follow the flowchart below to discover which voltage is not present. In case short circuit is
discovered on some power supply, it is highly recommended to temporarily desolder
corresponding inductor to increase the possibility of finding shorted element.
Check for Input voltage on C12 Input voltage problem
OK
Check for 3.3V on C25 3.3V problem
OK
Check for 0.99V on C45 0.99V problem
OK
Check for 1.8V on C51 1.8V problem
OK
Check for 0.9V on C73 0.9V problem
OK
Check for 1.5V on C79 1.5V problem
OK
Check for 12V on C1005 12V problem
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Input voltage problem
SHORT
Check if C12 is not short Check 3.3V
OK
Check power supply unit Replace PSU
OK
Check D1 diode Replace faulty diode
OK
Board is not repairable
3.3V supply problem
SHORT
Check if C25 is not short Check 0.99V
OK OK
Check if L1 is not heating up and resistance Check 1.8V
OK OK
Change U6 Change L1 Check 0.9V
OK
Check 1.5V
OK
Change Q4, Q5 & U6
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0.99V supply problem
SHORT
Check if C45 is not short Board is not repairable
OK
Check if L3 is not heating up and resistance
OK
Change U8 Change L3
1.8V supply problem
SHORT
Check if C51 is not short Check U2, U3, U4
OK OK
Check if L4 is not heating up and resistance Replace U2 or U3 or U4
Change U9 Change L4
0.9V supply problem
SHORT
Check if C73 is not short Check U2, U3, U4
OK OK
Check if L5 is not heating up and resistance Replace U2 or U3 or U4
OK
Change U10 Change L5
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1.5V supply problem
SHORT
Check if C79 is not short Check U5
OK OK
Check if L6 is not heating up and resistance Replace U5
OK
Change U11 Change L6
12V supply problem
SHORT
Check if C1005 is not short Board is not repairable
OK
Check if L1000 is not heating up and resistance
OK
Change U1000 Change L1000
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Routerboard does not boot
First of all, check all the electrolytic capacitors on the PCB. In case if some capacitor are
swollen or damaged, replace it with the new one. Parameters such as capacitance and
voltage rating of the corresponding capacitor are printed on its case.
Check 0.99V supply Go to 0.99V problem flowchart
OK
Check 1.8V supply Go to 1.8V problem flowchart
OK
Check 1.5V supply Go to 1.5V problem flowchart
OK
Check X101 (156.25MHz) Replace X101
OK
Check X100 (25MHz) Replace X100
OK
Replace SDRAM U5
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Temperature reading – FAILED / Overheating
Check if both heat
sinks are positioned Adjust the heat sinks
properly
OK
Check whether
fans are Measure 12V supply
spinning
OK
OK
Check whether OK
PWM signal is
applied to fans
Board is unrepairable
Replace fans
Go to 12V supply
problem
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One of ethernet ports (1-8) does not work
Check diode
array next to Change faulty diode
TR600 and TR601
OK
Check TR600 and TR601 Change faulty transformer
OK
Check resistors R600-R623 Change faulty resistor
OK
Check J600 Change faulty socket
OK
Check U2 Change faulty component
One of ethernet ports (9-16) does not work
Check diode
array next to Change faulty diode
TR602 and TR603
OK
Check TR602 and TR603 Change faulty transformer
OK
Check resistors R624-R647 Change faulty resistor
OK
Check J601 Change faulty socket
OK
Check U3 Change faulty component
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One of ethernet ports (17-24) does not work
Check diode
array next to Change faulty diode
TR604 and TR605
OK
Check TR604 and TR605 Change faulty transformer
OK
Check resistors R648-R671 Change faulty resistor
OK
Check J602 Change faulty socket
OK
Check U4 Change faulty component
One of POE-OUT does not work
In case some of POE-OUT ports does no work, PSE-24 modules should be checked. If all
connectors are good, but POE-OUT still does not work, problem can be solved only by
Mikrotik service.
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SFP+ port1 doesn’t work
Check J800 for debris / Clean connector
dirt with contact cleaner
OK Change faulty connector
Check for 3.3V on
L800, L801 Change faulty inductor
(on both sides of each)
OK
Change U803, U805
Change U800, U804
SFP+ port2 doesn’t work
Check J800 for debris / Clean connector
dirt with contact cleaner
OK Change faulty connector
Check for 3.3V on
L800, L801 Change faulty inductor
(on both sides of each)
OK
Change U806
Change U800, U804
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SFP+ port3 doesn’t work
Clean connector
Check J800 for debris / with contact cleaner
dirt
OK Change faulty connector
Check for 3.3V on
L802, L803 Change faulty inductor
(on both sides of each)
OK
Change U800, U802
Change U803
SFP+ port4 doesn’t work
Clean connector
Check J800 for debris / with contact cleaner
dirt
OK Change faulty connector
Check for 3.3V on
L802, L803 Change faulty inductor
(on both sides of each)
OK
Change U800, U802
Change U803, U806
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Serial port test failed
Check RJ45 connector
J401 for debris / Clean connector
dirt with contact cleaner
OK Change faulty connector
Change U403
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Components placement
Refer to Pictures 8,9,10,11.
Picture 8
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Picture 9
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Picture 10
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Picture 11
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Components list
Ref. Num. Part number Manufacturer Description
Lite-On
L15ESDL5V0N
D700-D747 Diode Array TVS 150W 4 channel
Semiconductor
A-4
low cap DFN-10
corporation
88E1680-A2- Octal PHY with 2x QSGMII
U2-U4 Marvell Asia Pte Ltd
LKJ2C000 11mmx20mm 128-LQFP
DW-918-26- Dragon Well RJ45 2x4 w/oLED w/Shield TH
J600-J602
01TP-02 Electronics Co.,Ltd. w/oEMI GF PA46
10/100/1000 Quad port Ethernet
Bothhand Enterprise transformer TH 88pin wider w/PoE
TR600-TR605 PGH5610RS LF
Inc. connector 29.1x28.7x19.5mm
802.3at
WENZHOU YIHUA
COMMUNICATED Connector SFP Cage 2x2 Press
J800 10705322D011 Fit w/oLight Pipe (CZT Layout)
CONNECTOR
CO..LTD (CZT) 30u Ni plating
SJS89-E105E6- Dragon Well
J401 RJ45 w/oLED w/oShield TD SMD
03TR Electronics Co.,Ltd. w/oEMI T&R (7.8mm) 3u" LCP
U800 74HC595T16-13 Diodes Incorporated 8-bit shift-and-store latch
74HC165PW,11 IC 8BIT PARALLEL-LOAD SHIFT
U802, U804 NXP Semiconductors REGISTERS TSSOP16
8
Unisonic
U803, U805, U74LVC1G3157
Technologies CO., SPDT Analog Switch SC70-6
U806 G-AL6-R
LTD. (SOT-363)
Viking Tech
L800-L803 CB03YTYH121
Corporation Ferrite Bead 120 Ohm 2.5A 0603
Crystal Oscillator 25MHz 20ppm
X100 7C25000123 TXC CORPORATION
3.3V 15pF -10+70 5x3.2
Crystal Oscillator 156.25MHz
PSE Technology 50ppm 3.3V LVPECL, Jitter 0.8ps,
X101 WX72F62007
Corporation
Tr/Tf 600ps, -20+70 7x5
4.5V to 28V Input, 3A,
TPS54302DDC
U1000 Texas Instruments Synchronous, Step-Down
R
Converter SOT23-6
C1005, C25,
MC05MTX6V32 Viking Tech
C45, C79, C51, Capacitor 22uF ±20% 6.3V X5R
26 Corporation
C73 0805
BCRH8D43- Bao Cheng Inductor 10uH 30% 3.6A 34mOhm
L1000
100N-NL Electronics Co.,Ltd., 8.3x8.3x4.7
BCIHP0750LD- Bao Cheng Inductor 3.3uH 9.5A 15mOhm
L1
3R3M Electronics Co.,Ltd., 6.8x7.3x5.0mm SMD RoHS T&R
Latest document “Checking procedure for overvoltage damage” available at www.mikrotik.com 21
Ref. Num. Part number Manufacturer Description
Advanced Power Transistor MOSFET N-Ch 40V
Q4, Q5 AP9467AGM-HF
Electronics Corp. 11A 11.5mOhm SO-8
NANYA DDR3L SDRAM 4Gbit DDR3L-
NT5CC256M16
U5 TECHNOLOGY 1600 (800MHz) 256Mx16bit
DP-DI
CORPORATION [F] FBGA-96 1.35/1.5V 0-95C
Samsung
CL31B103KGF
C12 Semiconductor Capacitor 10nF ±10% 500V X7R
NNNF
Europe GmbH 1206
Lite-On
D1 B340LB Semiconductor
corporation Diode Sshottky 40V 3A SMB
Step-down Converter 2.95V-6V IN
U8, U9 TPS54719RTER Texas Instruments Inc 0.6V-4.5V OUT 7A 2MHz
frequency 3mmx3mm QFN-16
BCIHP0530- Bao Cheng Inductor 1.5uH ±20% 6A 25mOhm
L3-L5
1R5M Electronics Co.,Ltd., 4.9x5.2x3.0mm SMD
Lite-On High Efficiency PWM Step-Down
U11 LSP5015AAAD Semiconductor DC/DC Converter 1.5MHz, 1.5A,
corporation SOT-23-5
Bao Cheng Inductor 2.2uH 2.6A 44mOhm
L6 BC43-2R2M-NL
Electronics Co.,Ltd., 4.5x4x3.2
Viking Tech
R600-R671 CR-03FL7---75R
Corporation Resistor 75R 1% 0603
Synchronous Buck
Richtek Technology
U6 RT8209BGQW Controller,Vin=4.5...26V, WQFN-
Corporation 14L_3.5x3.5
3v to 5.5V RS-232 LINE
U403 MAX3243CPWR Texas Instruments Driver/Receiver
Synchronous Step-Down
U10 TPS54319RTER Texas Instruments Converter 2.95V-6V input, 3A adj
output, 2MHz 3x3mm reel QFN-16
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