This doesn't exactly fit but it's close enough.

This was in 2016 or 2017.

A good friend of mine was in need of a new PC and wanted to buy a prebuilt. I gently (maybe not so gently) told him that was a waste of money and I could build a better one for cheaper. So I put together a decent budget oriented mid tier build for him. i5 and a GTX 1060 6gb. All was well at this point. We ordered the parts to his house and I got on a train to his city to put it together.

At this point in time, I wasn't an expert on building PC's. I had built two PCs in total. both very budget oriented.

So we (I) start building the PC. All goes well. Each part at it's place. Each cable connected (supposedly). Press the power button. doesn't POST. reseat everything. doesn't POST . My friend is getting very anxious at this point which is slightly annoying to me... Saying he should have just built a prebuilt. This in turn is making me uneasy. We decided to take it a PC shop so that they can test if a component is dead. And mostly to ease his anxiousness.

We take the whole computer, which is basically 'ready' in a cardboardbox to the pc shop. Taking public transit with a huge and decently heavy box isn't that comfortable. Arriving at the PC shop we explain the problem to the worker. He takes one look at it and goes: 'You haven't connected to 6pin power cable for the CPU'

Cue embarassment. But also relief that it was just a stupid oversight, fitting to my inexperience.

Back in his home, we connect the cable. It posts. all is good. Mainboard has no wifi built in so we get an ethernet cable. No connection. Ethernet doesn't work. I tried everything that I could and it didn't work. He bought a cheap usb wifi adapter. which works. To this day The ethernet doesn't work. He is still using that PC. I'm telling him he should upgrade it, or more like replace it completely.

He want's to buy a prebuilt. I tell him I can build him a pc for better and cheaper. I feel like im experiencing a deja vu. Hope the second round goes smoother..