2nd PC, old/low tier - looking for ideas, what to do

Back to the old storyline, a bit over 6 years ago I built a nice quiet mid-range gaming PC. Recently it developed problems though and refuses to boot. Troubleshooting is still ongoing but on Asus forums they suggested it is maybe the CPU.

PC spec is at http://www.tomshardware.co.uk/forum/300498-31-building-range-gaming-quiet-intel

I'm pondering what to do with that:

1) Build it up to be a 2nd desktop PC
2) Salvage and sell the parts
3) Just take it to garbage

1) Regarding this option, not sure if there are enough use cases. So I'm kind of looking for ideas concerning this. I could offload some tasks to the second computer. It turns out most of my time is spent on web forums and browsing for information online, though I usually build systems with gaming primarily in mind. But I have a pretty recent laptop which is well suited for casual browsing. Also there's 2-3 monitors available so I can keep Teamspeak and web browsers open on a 2nd monitor while the game is running already on the main 'puter. Offloading some applications to another computer of course helps with multitasking but a more compact approach would just be to get a Ryzen CPU and utilize its 12 cores.

This is a single person household, though there is potential to scale to 2 people or even beyond. This I think could bring the most multitasking benefits since multiple seats could be used and the applications needed would be more variable as well.

Regarding applications, first off this computer would need to run Linux (or BSD unix or something more exotic) because the cost of a Windows license is prohibitive in this scenario. That puts in some limitations regarding application support - multiboxing Eve Online is out as well as regular video editing (there is a performance issue too; Linux would be well suited to rendering and creating CGI animation though I have no interest in making animation, raytracing could be an occasional use case). It could be used perhaps to run some games, but that tends to concentrate on the main 'puter and also having 3 web browsing machines sounds a bit superfluous. Maybe I could use the box just to play around and experiment with Linux or possibly even to develop and test some software and things.

I have extensive skillsets in networking/embedded systems/software engineering so it could be utilized in some projects or for some server applications but at the moment there is not so much interest to alone justify retaining a 2nd contemporary level desktop. Do you have any ideas for exciting technical projects to undertake on this box? One possibility could be to use it as the workstation to control a 3D printer as that is maybe better to reside in a separate room.

For hardware, the Asus page https://www.asus.com/fi/Motherboards/P7H55/ says:

This motherboard supports the latest Intel® Lynnfield and Clarkdale processors in LGA1156 package, which has memory and PCI Express controller integrated to support 2-channel (4 DIMMs) DDR3 memory and 16 PCI Express 2.0 lanes providing higher graphics performance.

Click to expand...

Would it actually run with a modern CPU? Or maybe I'm looking to buy a CPU+MB+RAM combination, do you have suggestions? Dirt cheap is preferable but something that offers a bit of performance to balance would be attractive. 4-8 GB of RAM is what I think I'd be looking for - I take DDR3 is affordable nowadays and it's not exactly necessary to be of very high performance.

EDIT: Okay, reality check. They don't seem to sell LGA1156 processors in the store any more - potentially I could look for a 2nd hand i5 though. For this box it doesn't have to be Intel, if I buy a new MB an AMD one could be better suited due to the usually lower cost.

2) Some parts are still viable and there is also a 2nd hand PC component market in Finland. I doubt it's worth the hassle to sell the parts except for the most marketable ones which may have a minor financial value still. Mostly I'm wondering what to do with the case, it's a quite nice Antec one but there are already better ones on the market and I ordered a nice one for my new PC build.

Select parts such as the PSU and HDD can be moved to the new PC.

3) I may have to acknowledge that most of it is practically junk and needs to be taken to the local recycling center. This might be free of charge, last time I visited they were still willing to receive PC waste. There's also some older boxes now considered retro which I don't need and have to get rid of soon... a few will stay for my future retro computing interests.