I work with a lot of RMA cases (electronics retailer) and what I've noticed is that people don't tell much informations about the malfunction unless you pull the data out of them by asking them like a detective.
The reason I say this is because people in most cases just say "It doesn't work". You send it to service center (in Europe, stores are obligated to do this if customer wants us sending the stuff to service center), they plug the device in, it starts and they send it back because the "It doesn't work" isn't true. This is especially the case for malfunctions that appear over time and not right away (because the device has to warm up for it to show the fault or something similar). Service center plugs device in, tests for 15 minutes, all is well and they send it back. But they'd have to run it for 2 hours for the fault to show up. So, it's critical to describe issues as detailed as possible so you don't waste time sending stuff back and forth several times because the service center didn't have enough info to properly test the malfunction.
In this case, you should specifically state that fan is making noise when in horizontal, facing down position. They'd spot the issue right away. But like some said, they test it in test benches that are in most cases motherboards placed horizontally, meaning the graphic card was vertical and most likely not making any noises. I know it's impossible for customers to know how they test, but it's better to write down excessively detailed description of a malfunction than too little detailed.
So make sure to describe in details:
- what happened (what is the malfunction)
- how it happened (what were you doing when it happened)
- when it happens (is it constant, does it happen after specific time, under other specific conditions etc)
- describe in what position (because components can even be facing up with cases that have inverted vertical motherboards placement)
You can even write down something that isn't even listed above, but you think it might be relevant.
Just an advice for the future.