Hello Ananymous
I had to replace mine after several years of operation (fan was making extreme noise) and it still runs reliably through almost 24/7. Now longer than what was installed when I bought it.

The power supply units are reliable. I think the question is more whether it is the power supply at all. If there are problems when switching on, it could also be a problem with the parts installed at Synology: https://www.synology-forum.de/threads...