Lexmark ms812dn network card broken

[sunfire]

Hello,

I'm (trying to) repair a Lexmark MS812DN printer which does not connect to network. The network card status on the operator panel always shows disconnected. I tried multiple cables, multiple switches, tried to force a lower speed and duplex on the network port (on the switch), updated the firmware, nothing works. I took the mainboard out of the printer (the network card is onboard) and the physical connector port seems to have the magnetics builtin, it's made by PALCONN (part number RJT-11UC1F-G13). The network PHY chip is made by Marvell 88EC068, i attached a picture taken with my phone. I measured the resistance between the connector pins on the PCB and I'm intrigued by the results : the resistance between all the four pins of pairs 1 and 2 (connector pins 4, 5, 10, 11) is around 0.5 - 0.6 ohms, the resistance between all the four pins of pairs 3 and 4 (connector pins 2, 3, 8, 9) is also around 0.5 - 0.6 ohms. I was expecting the resistance between the connector pins 10 and 11, 4 and 5, 2 and 3, 8 and 9 to be low because I'm measuring the primary side of the transfomer in the connector but I wasn't expecting the resistance between all the four pins 4, 5, 10, 11 and 2, 3, 8, 9 to be low (i.e. I wasn't expecting the pairs to be connected to each other).

Is this normal ?

I removed the connector from the PCB and the resistance on the PCB pads looks to be what I expected : between the pins 4 and 5, 10 and 11, 2 and 3, 8 and 9 it's ~ 11.3 kohms. However, when comparing the resistance between pins 2 and 8, 3 and 9 (around 600-700 kohms) to the resistance between pins 4 and 10, 5 and 11 (around 1.6 Mohms) there is quite a bit of difference. Is this suspicious ?

I'm beginning to suspect the printer was connected to a PoE switch and this may have burned the magnetics in the connector and/or the network PHY chip.
Do you guys know of any sources where I can buy the connector and the Marvell PHY chip ? Preferably in Europe (I'm from the Czech Republic).
The only sources I found for the connector are the big players in US (Digikey, Mouser, etc), i found nothing in EU.
The Marvell PHY chip is even more unobtainium, I only saw it in the electronics trade markets in south east Asia (and they want a minimum order of 100 pieces).

Thank you for the help and sorry for the long post