whats that
no ups so zener diode flamer
badcaps also
big bulger is a planet one
some rulycon also
no ups so zener diode flamer
badcaps also
big bulger is a planet one
some rulycon also
Attached Files
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Re: KME PX-300w
Wow! Just wow! How much did it cost? (rhetorical)
Q6700 @ 3.6 GHz
Zippy GSM-6600P
Curcial Ballistix PC6400 (4 x 1Gb) Micron D9GMH
Abit IP35Pro
ATi HD4870 -
Re: KME PX-300w
looks like the p.o.s commited suicide!
did it kill anything in the pc when it went?Comment
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Re: KME PX-300w
Had a Zener diode die in a power spike in a really old Enermax 430w PSU years ago, swapped it out with a smaller one (had to desolder the bulkcaps to reach it)
It still runs fine to this day, it is probably around 5+ years ago...
The alu heatsink had clear cuts in it from the diode exploding...
But looks like your PSU was not so lucky..."The one who says it cannot be done should never interrupt the one who is doing it."Comment
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Re: KME PX-300w
Hot damn! Guess that means I'll have to check the zeners in that KME PSU I rebuilt.
Course I replaced just about all its capacitors (even the little buggers), so maybe it'll be OK for a little while...
That KME you got there, seems to use no better caps than the POS I was working on. (Bigger input caps, but I'd doubt that there was a secondary cap bigger than 1000uf in there.)Last edited by UraBahn; 10-03-2006, 10:34 AM.The ever-amazing (and ever-affordable) KY, Chemi-con's best kept secret.
I'll probably be the only person going to SteamOS once it gets out of beta (ha ha.)Comment
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Re: KME PX-300w
it burnt on the other side of the primary heatsink also
didnt post with another psu but it was all old crap anyway.Attached FilesComment
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Re: KME PX-300w
The thumb in the air symbol on MaxUS is cute. You know what that translates to in other countries?
Here it means, this is really good or, A-OK, other places it's a sarcasm for thumb up your ... more literally.JimComment
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Re: KME PX-300w
it wasnt a zener. whats that?
Attached FilesComment
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Re: KME PX-300w
Probably a big red cap.Comment
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Re: KME PX-300w
Looks like a metallized film (probably polyester) cap.PeteS in CA
Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
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To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
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Re: KME PX-300w
Did you put a blow torch on that?JimComment
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Re: KME PX-300w
Just my theory, it might have shorted out, and the intrinsic resistance been enough for it to flameout. I don't think polyester caps are low resistance.Comment
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Re: KME PX-300w
Theoretically, metallized film caps are self-healing - if there is a dielectric breakdown, the arc clears the metallization around the area. In reality, the arc also leaves some carbon, which is very high resistance, but still conductive. If more arcs occur (e.g. due to voltage surges, weak spots in the film) the number of conductive areas increases, each of which generated a little heat. Eventually the cap can catch fire. IIRC, the paper/article I read on this mentioned that there had been some polyester or polypropylene fim X-caps in TV sets in Europe that had caught fire. The article was probably in a Wima or Rifa catalog, late 80s vintage.PeteS in CA
Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
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To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
****************************Comment
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Re: KME PX-300w
i think it was a voltage surge. it was not on upsComment
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Re: KME PX-300w
If the scenario I described is the case, then it would have been cumulative damage over months (or over a year or two). I'll defer to your familiarity with your local power conditions.PeteS in CA
Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
****************************
To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
****************************Comment
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Re: KME PX-300w
That's the blocking cap in series with the transformer primary in a half-bridge configuration - usually rated at 1 kV. The surge had to have been momentarily capable of charging the primary-side electrolytics to +500 VDC to cause this cap to fail - in which case the MOVs should have blown first, followed by the fuse and/or bridge rectifier and/or primary switching transistors.
My guess is that somebody bypassed the fuse in a previous repair with a low-resistance shunt, or that polyester cap was marginal/defective during manufacture. I've never seen such a failure, even on a Deer/L&C.Comment
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Re: KME PX-300w
PSU has never been repaired. Its the original purchased with a new PII 300 slot 1.
If such a strong voltage surge would have been required then it should have affected other devices. so probably dielectric breakdown over the years like Pete said is a factor.Comment
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Re: KME PX-300w
Hmmm, that it was a DC-blocking cap for a half-bridge inverter crossed my mind, though I think I've seen 400V or 630V parts used in that role. If it's a DC-blocking cap as per above, it also carries the primary current of main transformer, so all the usual I(Ripple) - ESR stuff applies (ya just can't escape Mr. Ohm and Mr. Watt).PeteS in CA
Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
****************************
To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
****************************Comment
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