the fans should need approx 100mA @ 12VDC. You have to check the fans!
a LMC7660 can not produce that much power. A 3-6Watt 5/12VDC switcher maybe.
rw

No. These are real small and thin fans and don't turn all that fast.
They were on some of the early 486's. Even stalled they only pull about
25 ma.