Sum-vision KY-550ATX inrush current limiter

[Radio Fox]

My PSU "popped" a couple of days ago. Looks like the inrush current limiter has blown. Unfortunately the part of the component that came away has disappeared. It's the green component in the photo.

Does anyone know the full markings for this component? I tried looking at a few websites with manufacturers logos on them, but couldn't find this one. The component still measures 6.6 Ohms in-circuit.

The board is marked TB-1.2 REV:1.7

[Toasty]

Re: Sum-vision KY-550ATX inrush current limiter

Find one from a junker PSU of equal or greater current rating (5A per the label). It's okay to put one from a 600w unit in there.

[seanc]

Re: Sum-vision KY-550ATX inrush current limiter

I've used some of those (400w) in older PCs to extend their life just a bit more - they're pretty cheap and nasty on the outside, is the inside better?

I'd pick up a better PSU if possible.

[mur]

Re: Sum-vision KY-550ATX inrush current limiter

This is a sunpro psu...

I had a smiliar one (labeled 300w) which had this NTC labeled 8S050M.

[370forlife]

Re: Sum-vision KY-550ATX inrush current limiter

Wow look at the fuse on that thing!

[seanc]

Re: Sum-vision KY-550ATX inrush current limiter

I thought that too!

[mur]

Re: Sum-vision KY-550ATX inrush current limiter

Yep it's very definitely blown. You can see few burned resistors around 5vsb circuit and the big 5vsb transistor was shorted and the small 5vsb transistor blew itself in half. Oh and look at the bottom of c19 cap(5vsb filtering).

[Radio Fox]

Re: Sum-vision KY-550ATX inrush current limiter

I have actually replaced the PSU, so there's no urgency to get this one going again. Other than the component thats blown, I don't think there is anything else wrong, as the PSU carried on working after the "pop", giving me time to shut the PC down normally. Although I haven't powered the PSU up again since.

I don't have any suitable scrap units, apart from 2 (very) old PC's which probably only have 200/250W PSU's.

Thanks for the photo mur. It gives me an idea of what I have.

[Toasty]

Re: Sum-vision KY-550ATX inrush current limiter

>>Wow look at the fuse on that thing!<<

It's why ceramic fuses are a better (safer) choice.

@Radio Fox -

Mouser stocks a huge number of these in varying "flavors". (or is that "flavours"... )

http://mouser.com/Search/Refine.aspx...rd=ntc+limiter

Here's a link to Epcos' ICL's datasheet:



Toast

[Radio Fox]

Re: Sum-vision KY-550ATX inrush current limiter

Thanks for the links Toasty.

[momaka]

Re: Sum-vision KY-550ATX inrush current limiter

It does look like a Sun Pro as mur suggested. If it really is, don't bother! They use the cheapest caps possible, have tiny heatsinks and undersized components, and almost always a charred PCB as a consequence of that. Not worthwhile to fix in my opinion. Definitely something I'd never put in a working computer again.
But if you want to fix it for the sake of it, then why not. Keep in mind that the 450 watt rating on the label is a complete lie - this PSU won't do more than 200 watts, if even that much. With that said, a NTC from one of the old power supplies you have might work just fine.

[370forlife]

Re: Sum-vision KY-550ATX inrush current limiter

Fox's psu isn't sunpro. Don't know what that is without a more detailed shot. Can't be too good, still has the 4 diode treatment.

Mur's psu is a sunpro, you can tell by the bright yellow transformer and just the text they use.

[momaka]

Re: Sum-vision KY-550ATX inrush current limiter

I think it is. Model number on this one is KY-550ATX. If you look up Sun Pro on the UL site (E210743), their page has many other PSUs with this KY-xxxATX m/n format. And then there's the mismatched input diodes, which is something I've only observed in Sun Pro and Powmax/Leadman PSUs.
Well whatever it is, it's still a "HAZARDOUSAREA" .

[Krankshaft]

Re: Sum-vision KY-550ATX inrush current limiter

>>Wow look at the fuse on that thing!<<

It's why ceramic fuses are a better (safer) choice.

I was thinking the same thing when I saw that pic.

Look at the remains of the glass is that all vaporized filament? Looks like someone tinned the glass envelope.

I think that's because the fuse was cheap Chinese crap I only buy and use fuses from Littelfuse and Bussman.

From 15 amps and up go Ceramic anything under that glass is fine.

[Radio Fox]

Re: Sum-vision KY-550ATX inrush current limiter

On second thoughts, it's probably not worth the time & effort trying to repair. It did come out of a very cheap PC, so I'll just keep it for spares.

Thanks for all your suggestions.

[stj]

Re: Sum-vision KY-550ATX inrush current limiter

I think that's because the fuse was cheap Chinese crap I only buy and use fuses from Littelfuse and Bussman.

no, it's because it's just glass, bussman / littlefuse would do the same.

that's why you can get glass/sand filled fuses and like you noted, for safety situations there is glass / sand filled ceramic.