Any ideas?

Hello, I have issue with Dell Inspiron 3542.

Motherboard marking:
[CODE]Cedar_Intel-MB 13269-1
PWB FX3MC REV: A00 [/CODE]

The laptop works just fine (on battery and power supply) and doesn't cause any problems, except those described below:[LIST=1][*]The first problem is that the RTC/CMOS battery self-discharges after about 2-3 weeks after installing a new battery. I have been installing different batteries (GP, Duracell, Energizer) and the problem still exist.[/LIST][LIST=1][*]The second problem is the LAN network card (Realtek RTL8106E), which is not detected...