The ATX supply will ride out the glitches much better due to its higher current ratingI suspect. Try putting 10 ohms in series with the fan and see if that cures the problem,if so then the switching glitches definitely crow-baring the 12V supply as I suspect.If not its something else (noisy supply?)
Please enter a valid email to subscribe
We need to confirm your email address.
To complete the subscription, please click the link in the
email we just sent you.
Thank you for subscribing!
via Egeo 16