This is the thread I used for the fan replacement: OPUS BT-C3100-Stock Fan VS. Top Tier Delta fan
(typically, pictures are now missing).
You can : 1) lube the fan routinely. It’s not hard. It does not improve performance, simply keeps it from deteriorating. 2. Replace fan with same. Do a search on [Opus BT-C3100 fan replacement] and you’ll get hits on where to get some and how to replace it. 3. Replace with superior fan as above.
Note - for those not happy with fan noise of the Opus will NOT LIKE this mod. Tiny fans turning fast simply whine. No good way around it.
Note 2 - I saw a mod to 3-D print an adapter that grafted a larger fan into the space the small fan fits. This would be great if you have the tools and expertise. Increased flow, decreased noise. Or….just sit it on top an 80mm PC fan or point a small fan at it.
The power plug is fairly standard for chargers of this type. I got a cheap 12v/5A power supply from a PC recycle store. Took the charger in to make sure it fit. I’ve seen essentially identical PS sold on line for less than $10. I think the newer PS it comes with is now up to the task. Earlier PS were not if pushed at all.