Dell C1765nf hangs some seconds after boot

Hello,

my Dell C1765nf printer stops working after some seconds after power on.

The buttons does not react and I already figured out that some seconds after start the web interface is not accessible at all.

So it seems that the boot is successful but crashs after some seconds.

I was already able to locate the motherboard and found the UART interface, but was not yet able to get any information out of it.

Are there any electrical components know to fail and cause this kind of problems?

EDIT1: I did a little further investigation and found out that the printer only crashs when the ethernet port is plugged in. If I remove the ethernet cable the printer keeps responsible. I also connected the printer directly to my laptop, giving it an ip address with dhcp. This also don't crash the printer.