Do I need to replace the motherboard

[kamrulehug]

I bought a Asus AS-870-PRO Desktop PC in Apr 2011 and paid for extended warranty. (http://computersbds.blogspot.com)
PC could no longer access internet in Dec 2012 - Network Adaptor need to be replaced.

Spoke with the PC repair technician engaged by the warranty company and was told that there are 2 options :
1) install a new network adaptor
or
1) replace the motherboard with a different model-the motherboard that come with my PC is no longer being manufactured

The technician's advice to me is to just "add the network card to minimise change"
The warranty company will call me today to go through the options.

I would be grateful if someone could advise me on which of the above options to take.
Many thanks in advance.
I have backed up my file using Acronis True Image.

Appended below are some reviews of the PC that I found online:

[rp12]

Well, it is difficult to say right now. You need to make a special diagnostics and only after that I would be clear. Anyway, next time, when you're going to by a new motherboard, follow these rules www.thewiredshopper.com (https://thewiredshopper.com/guide-choosing-motherboard/). It will help to save money and avoid situation like this.

[Kayleng]

Well, it is difficult to say right now. You need to make a special diagnostics and only after that I would be clear. Anyway, next time, when you're going to by a new motherboard, follow these rules www.thewiredshopper.com (https://thewiredshopper.com/guide-choosing-motherboard/). It will help to save money and avoid situation like this.

It was quite an old post, I don't think that the author still tracks this thread