My fan stops rotating last month, causing the temperature to reach beyond 56 degrees as indicated in the unit's admin web page. As set to its threshold temperature level, DNS-320L is shutting down automatically. I did replace the AVC cooling fan with HXS branded one with the specs below, which I think it matches.
https://shopee.ph/40mm-Silent-Case-Fan-12V-Mini-Cooling-Computer-Fan-40mm-x-10mm-DC-Brushless-3-pin-for-CPU-Desktop--i.206467147.7014357858
However, after connecting it, maybe due to the cool weather at present, DNS-320L is up and running for more than 12 hours until now but the fan is still not rotating. Before returning to its chassis, I checked that the fan is not rotating although the blue button is blinking to power up. I've followed the instruction on changing the polarity because the red and black wires received from the package were interchanged (from this forum's replacing the fan thread). Bought 2 units and tested working but not working when connected to DNS-320L.
Is there a way to diagnose this? Is there indicator that the NAS detects this fan? Tried also changing the setting from AUTO to MANUAL to set the fan high but the admin website indicates 0 RPM and checked that the fan's blade is not swirling. How can I isolate the problem without the use of instrument or device to measure the volt/ampere in its pin terminal? Thanks.