The Hall of Shame - Badcaps Photo Montage

[Uranium-235]

Originally Posted by televizora

These are a low power shottky diodes. Perhaps 1A/50V shottky diode will replace it just fine. Unless it's something special that requires this exact signal diode. D should be rectifier diode. If it was ZD, then It would be zener diode.
And you are right. They were producing shottky, zeners and other stuff in glass package.

just looked through mouser, couldn't find any glass 1a/50v (looking at 150C temp). But I guess a schottky is a schottky

[televizora]

Originally Posted by Uranium-235

just looked through mouser, couldn't find any glass 1a/50v (looking at 150C temp). But I guess a schottky is a schottky

1A/50V was a suggestion. Glass shottkys have a typical current rating of a maximum 200-300mA up to 1A and a typical rating of maximum 100V.
Looking at the schematic and the fact that you have 25V Capacitor nearby, I concluded that the maximum possible voltage would be 25V. Then any 25V and over will do the trick. Also it has to be more than 500mA.
You don't need glass shottkys, glass packages are old design.
It would be better, if you can find schematic. I'm only trying to make educated guess.

[Uranium-235]

found service manual. D938. References Q654. Also had a diode list but not sure which one it is. I'm a professional computer tech, my exp with circuits is limited

[piernov]

Page 33 on the schematics, in the "POWER PART", D928 is a 1SS133 diode. A 1N4148 should be a suitable replacement and it's much more common.

[televizora]

So, I was right....

[Uranium-235]

but the forward fv of the 1N4148 is 1v, where the 1SS133 is 1.2

[televizora]

200milivolts are not critical.

[ilandsproblembarn]

i have an 30MDF35V capacitor i need identifying. this post is just so i can get priviligies to make my own post

[televizora]

Badcaps killed HP desktop computer with Intel mobo. On the mobo there were Rubycons - many of which - bulged. Then voltage without filtration and dead vrm..and shorting the chipset...

[Dannyx]

Here's my own little interesting encounter with faulty caps: two 470uF reservoir caps on an ATX power supply experienced catastrophic failure. The caps were installed by me about an year ago, as this is a refurbished junky 400w Delux PSU and of course it wasn't worth investing in quality caps which might've ended up costing more than 2-3 of these supplies together....looking at the damage, you'd think there's NO WAY the primary is still functional, but it's actually fine - not even the fuse went ! :|The story is even funnier (for an electronics nerd): the guy who tossed it said his daughter freaked out when she heard a loud bang from underneath the desk and saw some smoke coming out of the computer. I thought to myself "Ok, probably a FET shorted and took out the fuse and possibly some or all of the diodes", but then he followed saying he tried plugging the PC back in and ANOTHER pop accompanied by the obligatory magic smoke of course. I was pretty stumped myself at this point and thought maaaaybe someone somehow shunted the fuse or replaced it with one with too great a value in the meantime, but then I took the cover off and saw THIS The cause of failure was likely some liquid which spilled onto the back of the PC and into the supply, because there were dribbles of coke or perhaps coffee all over the inside of the PSU's case...that combined with the low quality caps resulted in this wonderful effect

[Behemot]

Don't see any coke or coffee.

[Dannyx]

I do Though you're right, the liquid gathered on the cover of the PSU, because when installed in a PC it normally faces upside down, meaning the board was at the top and cover was at the bottom...some of it might've oozed under the board as well.

[Behemot]

I'd expect that to be electrolyte from the exploded caps.

Which do not seem to ever be replaced when the glue on them has same structure and color and continuity with the glue on the board. Maybe it just appears that way, after all, they usually apply the glue in same spots, but still…

[Dannyx]

Originally Posted by Behemot

I'd expect that to be electrolyte from the exploded caps.

Which do not seem to ever be replaced when the glue on them has same structure and color and continuity with the glue on the board. Maybe it just appears that way, after all, they usually apply the glue in same spots, but still…

Well I repaired many of these exact same PSUs and distinctly remember replacing the large caps on one of them, so I could be mistaking it for that one....you're right, I didn't even notice the glue...either way the damage's been done

[PeteS in CA]

That looks like what I'd expect to see from a PSU set for 115VAC but plugged in to 230VAC, if there are no MOVs protecting the big caps.

[Dannyx]

Originally Posted by PeteS in CA

That looks like what I'd expect to see from a PSU set for 115VAC but plugged in to 230VAC, if there are no MOVs protecting the big caps.

Good call, though there's physically no way that could've happened with this particular one as we're rated at 230v

[RukyCon]

This is the first time i've ever seen the electrolytics in a CFL fail...

Brand: ymin
Line: RKF

[Behemot]

That's very common. After about a decade of daily use even Rubycon failed. It was still the very longest working CCFL bulb we ever had though.

[RukyCon]

I found what looks to be a server of some sort.
I don't see why they threw it out on the curb.

For those who failed to catch on, that was sarcasm.
Poor rubycon capacitor.

[momaka]

Those KZG caps next to then don't look that much better either
The server probably ran pretty hot to cook those Rubycon caps. I've only seen MCZ fail in locations where they were exposed to heat. That bare Intel chipset does typically run quite hot.