Fan siezed, PFC burnt in CFT-620-A12S

[pdavid]

Hi!

I got this psu that seemed to be a quick fix at first. Turned out that the fan bearing got stuck and all the caps plus the PFC boost coil got boiled. The guts come from Sirtec. It's an old build, but looks decent enough. Looks far better than any gutless unit today...

The main trafo and secondary torroids, pi coils seem good, but the active pfc is way too damaged for safe operation.
Does anyone might have info about the core material? Looks like it was green/black originaly.
I have a lot of spares or I can just wind one, that matches the diameters and windings and inductance. Might just build in one and see if it fits to the specs...

[ReeceyBurger123]

Re: Fan siezed, PFC burnt in CFT-620-A12S

Does the coil have 0 ohms across the two legs ? If so its good lol its only a filter.

[tom66]

Re: Fan siezed, PFC burnt in CFT-620-A12S

Does the coil have 0 ohms across the two legs ? If so its good lol its only a filter.

a) that's not just a filter, it's an active PFC inductor

b) no...just no...an inductor is more than just zero ohms between a pair of legs

[ReeceyBurger123]

Re: Fan siezed, PFC burnt in CFT-620-A12S

Whoops my bad guess I got mixed up again lol

[pdavid]

Re: Fan siezed, PFC burnt in CFT-620-A12S

Coil measures 0.3, 0.4 ohms. The enamel is burned off some areas and it could get shorted. The toroid core is beyond repair too. I got plenty if spare coils suitable for APFC boosting, some new some from similar apfc topology psus.

[stj]

Re: Fan siezed, PFC burnt in CFT-620-A12S

why not download a datasheet for the pfc controller?
most have example circuits with component details.

[pdavid]

Re: Fan siezed, PFC burnt in CFT-620-A12S

It's just a cm6800 in the primary. I guess any 400-600uH coil, with thick enough wire, will do for this max wattage.