Cisco catalyst 2960c POE

[madan1]

Hello everyone.

Got a catalyst 2960 from the usual scrapyard - ebay.
It is stuck in bootloop and the power supply is missing the 3.3v rail. (+12V, -53V, +3.3V)
Some green moisture crystallization on mainboard, which cleared very well with IPA and visually there is nothing rusted or gone.
Still working on the PSU to get the 3.3v rail back (waiting for parts), but for now I'm using an external buck converter board hooked up to the 12V rail ( by the way, the switch seems to be working with only 12V ).

The switch fails to boot due to the following POST error:

POST: PortASIC Port Loopback Tests : Begin
POST: Failed PortMacLoopback Packet Receive asic_index 0 port_hardware_index 1
POST: Failed PortPhyLoopback Packet Test asic_index 0 port_hardware_index 1
POST: PortASIC Port Loopback Tests : End, Status Failed

Error: ASIC/PHY POST failed. Cannot continue.

According to the Internet, the ASIC is dead and the switch is just a paperweight.

After forced boot with "-skip_post", the switch boots fine, all RJ45 ports (8 fastEth. + 2 giga.) work fine. I can not test the 2 SFP ports. The POE also seems to be working fine.
In brief - the switch does switch and provide POE so basically all I need from it.

So any ideas on how to proceed?
If the switch switches is it really possible that the ASIC is dead (like the switching to be going on PHY level without any ASIC input/control)?
Any ideas what asic_index 0 and port_hardware_index 1 actually mean? Like asic_index 0 is the connection to let's say the ethernet controller (in this case a single broadcom BCM5248)? Is port_hardware_index X the ethernet port X?

I'm new to cisco IOS and just getting to know the basics. Is there a way to force it to boot every time with -skip_post?
Here are the boot settings:
switch#show boot

BOOT path-list : flash:c2960c405-universalk9-mz.152-7.E8.bin
Config file : flash:/config.text
Private Config file : flash:/private-config.text
Enable Break : yes
Manual Boot : no
Allow Dev Key : yes
HELPER path-list :
Auto upgrade : yes
Auto upgrade path :
NVRAM/Config file
buffer size: 65536
Timeout for Config
Download: 0 seconds
Config Download
via DHCP: disabled (next boot: disabled)

Any help is appreciated.
Thank is advance.





P.S. OK, I think I found the faulty port - It is one of the 2 gigabit ports (I was more focused on testing the ports with POE and almost skipped the gigabit ports by just checking if the IOS detects the connection).
Here is what the IOS shows on that port
"Gi0/2 connected 1 a-full a-1000 Not Present"

while the correct status is
"Gi0/1 connected 1 a-full a-100 10/100/1000BaseTX".

When no cable is connected:
Gi0/1 notconnect 1 auto auto Not Present
Gi0/2 notconnect 1 auto auto Not Present


There seems to be some kind of a transfer on that port (the LEDs are blinking on both sides of the cable), but eventually no connection is established.
Each gigabit port (1 rj45+1 SFP) is controlled by a dedicated Marvell® Alaska® 88E1112. So I guess now I have to find out if the controller is dead...

By the way - any idea how the loopback test works? Is it just checking the connection to the controller or testing if the TX RX lines are fine to the magnet/transformer or even the port itself?

[stj]

i would check the current transformers for open windings.
they are the first thing to get hit by EMP from a storm.

also you can have a bad transformer cause a gigabit connection to run at 100meg or 10meg because 10/100 uses 2 pairs and gigabit uses all 4 pairs