HX850w overheating and restarting PC

Hi,



My Pc habe been restarting with increasing frequency over time. Monitoring of system temperatures dosent show anything out of the ordinary.



Thru testing, it seems my PSU (HX850W), or something impacting it, is the guilty part. The PSU fan under load dosent seems to spin very fast. Also, I found out that the bellow air filter was clogged with dust.



I used a spare Seventeam 500w PSU I had, and the system worked OK for 1 day, without issues and its fan was like a hurricane (not original fan). Also the HX850w worked ok out of my case for some hours even under load, but the fan seemed to spin slow.



What wories me is that, even under load, the Fan seems to spin very slowly producing little air flow.



Having the 900D case, I will say that I never cleared its dust filter at the bottom. The PSU mount in that case makes the air go down to a cloged air filter about 1 cm away.



So my question are these:



- Can the combination of a slow fan and the clogged filter be the causes of the restarts?



- Should i worry about the slow fan even under load? What would be a good replacement for it?



Also, is there a Fan positioning in the case that can help the PSU dissipate its heat?





thanks in advance,