Our workplace was getting rid of older network devices. One of these seemed perfect for my home office. Quiet and plenty of 1Gb PoE ports. Unfortunately, they didn't provide any power, although the switch otherwise worked perfectly. I took it apart, trying to figure out what parts it uses to find replacements.
The power supply is manufactured by Delta Electronics, model: DPS-300AP-89. It provides three voltage outputs
54V 4.48A
12V 5A
3.3V 0.7A
While looking for a replacement, I found another model that may be a suitable replacement: DPS-300AP-97. Luckily, mine was not damaged.
Delta Electronics was not the only vendor of power supplies for the C3560CX series, later models also feature power supplies manufactured by Lite-On, such as the PA-3301-2B2
For both power supplies, Cisco uses the same part number: 341-0675-02. They are shared by the same family of switches
WS-C3560CX-8XPD-S
WS-C2960CX-8PC-L
WS-C3560CX-12PD-S
WS-C3560CX-8PC-S
There is almost no information on fixing PoE problems, but there is a general consensus , that PoE controllers are responsible for most problems. I followed this lead and decided to replace both controllers.
The Si3458B03-IM controllers (U4701, U5001) were manufactured by Silicon Labs, now acquired by Skyworks Solutions. Although there is no datasheet for the Si3458, there is one for the Si3459, which has the same number of pins (56 QFN) and modes of operation to manage 8 PoE ports.
Other switches may use PoE Controllers made by Texas Instruments: TPS2388RTQ
The controllers use N-channel MOSFETs as switches to provide power to PoE devices. The MOSFETs, FDMC3612 labeled Q4801-04, Q4901-04, Q5101-04 on the board, are manufactured by ONSEMI.
Replacement of the controllers was not necessary. When I took a measurement, 54 V was present on the 12 MOSFETs, as well as on the input to the Ethernet jacks, but not on the CAT6 connected cable. Only then did I start looking for more information about these type of RJ45 connectors. The 2x2 port mag connectors are manufactured by the Bel Fuse/Stewart/TRP holding companies. In addition to the RJ45 connector, they have built-in magnetics. MAGJACKs Part number: 0854-2x2J-GY-F are no longer manufactured. Potential replacements are manufactured under the TRP brand: 2250210-1, 2250211-1, 2250121-1, 2250139-1 but I could not find any vendor having them in stock.
Again, Cisco has found an alternative supplier, which is Molex. The 2x2 Ethernet connectors use part number: 172611-1000
A 58V quad TVS is used to protect PoE devices from line overvoltages. Part number PEP01-5841, marking 58E1, manufacturer: STMicroelectronics. On the board marked as CR4801, CR4901, CR5101.
After opening the rear metal shield of the MAGJACK, I found 8 burnt fuses, two per connector (1.5A 63V, Slow Blow/Time Delay, size 1206). After replacing them, the PoE devices immediately got power.
Repairing the switch turned out to be much simpler than I had originally anticipated.
The power supply is manufactured by Delta Electronics, model: DPS-300AP-89. It provides three voltage outputs
54V 4.48A
12V 5A
3.3V 0.7A
While looking for a replacement, I found another model that may be a suitable replacement: DPS-300AP-97. Luckily, mine was not damaged.
Delta Electronics was not the only vendor of power supplies for the C3560CX series, later models also feature power supplies manufactured by Lite-On, such as the PA-3301-2B2
For both power supplies, Cisco uses the same part number: 341-0675-02. They are shared by the same family of switches
WS-C3560CX-8XPD-S
WS-C2960CX-8PC-L
WS-C3560CX-12PD-S
WS-C3560CX-8PC-S
There is almost no information on fixing PoE problems, but there is a general consensus , that PoE controllers are responsible for most problems. I followed this lead and decided to replace both controllers.
The Si3458B03-IM controllers (U4701, U5001) were manufactured by Silicon Labs, now acquired by Skyworks Solutions. Although there is no datasheet for the Si3458, there is one for the Si3459, which has the same number of pins (56 QFN) and modes of operation to manage 8 PoE ports.
Other switches may use PoE Controllers made by Texas Instruments: TPS2388RTQ
The controllers use N-channel MOSFETs as switches to provide power to PoE devices. The MOSFETs, FDMC3612 labeled Q4801-04, Q4901-04, Q5101-04 on the board, are manufactured by ONSEMI.
Replacement of the controllers was not necessary. When I took a measurement, 54 V was present on the 12 MOSFETs, as well as on the input to the Ethernet jacks, but not on the CAT6 connected cable. Only then did I start looking for more information about these type of RJ45 connectors. The 2x2 port mag connectors are manufactured by the Bel Fuse/Stewart/TRP holding companies. In addition to the RJ45 connector, they have built-in magnetics. MAGJACKs Part number: 0854-2x2J-GY-F are no longer manufactured. Potential replacements are manufactured under the TRP brand: 2250210-1, 2250211-1, 2250121-1, 2250139-1 but I could not find any vendor having them in stock.
Again, Cisco has found an alternative supplier, which is Molex. The 2x2 Ethernet connectors use part number: 172611-1000
A 58V quad TVS is used to protect PoE devices from line overvoltages. Part number PEP01-5841, marking 58E1, manufacturer: STMicroelectronics. On the board marked as CR4801, CR4901, CR5101.
After opening the rear metal shield of the MAGJACK, I found 8 burnt fuses, two per connector (1.5A 63V, Slow Blow/Time Delay, size 1206). After replacing them, the PoE devices immediately got power.
Repairing the switch turned out to be much simpler than I had originally anticipated.
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