The Hall of Shame - Badcaps Photo Montage

[ben7]

Re: The Hall of Shame - Badcaps Photo Montage

Found this on the web. Badly bulged and overheated teapos. Notice the unbulged one has a light blue sleeve, whereas the bulgers have a blue/gray burnt looking sleeve!

http://i1274.photobucket.com/albums/...1003-00095.jpg

[UraBahn]

Re: The Hall of Shame - Badcaps Photo Montage

Ah, the joys of eBay! :P This time the seller was 'lpfixparts310'.

The item:
http://www.ebay.com/itm/280680668117...84.m1497.l2649

...And you can see what I got in the attachments. Concentric bungs, slightly sloppy printing, you know what to expect. Kinda hard to see in the pics, my camera really sucks. I cut several open and they bubbled slightly. Wonderful, they're pre-pressurized.

Raised a stink over it. They claimed they got their goods from a 'reliable seller'. Told them real Rubycons don't use these concentric bullseye bungs. They refunded my money with shipping. I agreed not to leave negative feedback (heh heh, _that's_ why they refunded my money) BUT I never said I'm not gonna roast them elsewhere...

So yeah. Stay the he-double-toothpicks away from 'lpfixparts310'. In the meantime these "beauties" will be going into the goody bag, awaiting when I get a variac or at least a powerful enough DC power supply to make em pop.

[Pentium4]

Re: The Hall of Shame - Badcaps Photo Montage

Leaking Ltec, from an Ablecom server PSU. Surely that super hot resistor had nothing to do with it

[PeteS in CA]

Re: The Hall of Shame - Badcaps Photo Montage

And what's with mixing that Ltec turd with that nice 1000uF, 10V UCC/NCC KY series part? WTH?!

[Pentium4]

Re: The Hall of Shame - Badcaps Photo Montage

I know, what a shame. Lucky for this PSU i will recap it when i have time. won't let that cap go to waste!

[momaka]

Re: The Hall of Shame - Badcaps Photo Montage

That resistors needs to go away. Any cap will have a rough life next to it regardless of brands.

[Pentium4]

Re: The Hall of Shame - Badcaps Photo Montage

Replace it with a different one or just remove altogether? In my experience the 3.3V rail is the most sensitive to changing/removing minimum load resistors. Probably because it isn't heavily used in modern computers.

[momaka]

Re: The Hall of Shame - Badcaps Photo Montage

Either replace with a different one or actually physically move it somewhere else in the case where it won't be cooking caps. Or you can also try running without it. I usually try that first. Most PSUs won't care as long as you have a motherboard hooked to them.

[c_hegge]

Re: The Hall of Shame - Badcaps Photo Montage

My usual tactic with those hot resistors is to solder them onto wires and use some thermal epoxy to stick them to the secondary heatsink.

[Pentium4]

Re: The Hall of Shame - Badcaps Photo Montage

And they don't mind having such long leads? Can you post an example of what you're talking about?

[mariushm]

Re: The Hall of Shame - Badcaps Photo Montage

Why would they mind? It's just a resistor, a load. Imagine it as a component inside your computer consuming power from 3.3v or whatever rail that resistor is connected to...

That's all that resistor is doing, faking a device consuming some power so that there's always something eating some power.

I was going to suggest soldering wires to the resistor, then covering the resistor and leads into heatshrink and gluing it or taping it to the metal case further away from the capacitors.

I'm against getting the resistors in contact with the secondary heatsink, for various reasons, but it should be fine.

[Heihachi_73]

Re: The Hall of Shame - Badcaps Photo Montage

Not mine, but these look like more dead KZGs (the site is in Spanish). http://id4retrodev.blogspot.com.es/2...-reparado.html

[Pentium4]

Re: The Hall of Shame - Badcaps Photo Montage

I think this brand is Sonjiu. It was in this little wall wart, it was going to power a modem 24/7 so I replaced it with a panny

[mariushm]

Re: The Hall of Shame - Badcaps Photo Montage

That's actually a classic transformer with a bridge rectifier (made out of 4 diodes) and the capacitor to smooth out the ripple.
The output voltage will probably be about 13-15v with no load.

I would personally use that transformer for some projects and replace the adapter with a cheap switching power supply - those classic transformers are more expensive sometimes compared to switching power supplies.

[Wester547]

Re: The Hall of Shame - Badcaps Photo Montage

Not my image, also found it on the web, but failed 8mm 1000uF 6.3V Rubycon YXGs...



It looks like they're close to the northbridge and FETs, all of which were probably rather hot. I know enough heat can kill any 'lytic but 1000uF 6.3V capacitor failures seem to be very commonplace on motherboards.

And what's with mixing that Ltec turd with that nice 1000uF, 10V UCC/NCC KY series part? WTH?!

In all seriousness, I've seen Delta do that a lot (mix Taicon, Ltec, and/or CapXon with Nichicon, Rubycon, and NCC capacitors, or just use all Ltec, Taicon, and CapXon).

[120volts]

Re: The Hall of Shame - Badcaps Photo Montage

Old Plasma TV


Dan (TV tinkerer)

[momaka]

Re: The Hall of Shame - Badcaps Photo Montage

It looks like they're close to the northbridge and FETs, all of which were probably rather hot.

I bet you it's the hot FETs that caused it. I've seen a lot of incompetent motherboard designs with that issue for various caps on the motherboard.

The Dell Optiplex GX270 motherboards have the same issue with 1 particular cap spot under the RAM slots. Anything will cook there, except maybe for Panasonic FJS. And even those may have failed but just not shown it. The hot MOSFET next to that cap spot runs so hot that it actually will cause a burn to your skin! So most likely, it is running at 70C on the case at the very least. I probed some MOSFETs on an ASUS socket 939 motherboard before (not sure what model, but it was in an Acer PC) with a thermocouple, and they were running 75C with the PC just idling. Probably ran even much hotter with the case closed and PC at 100% usage. Just the SB in that machine was running at close to 60C - of course because there was no heat sink on it. With just a simple aluminum heat sink with no fins, I was able to bring it down to 50C - and that's at max PC load.

Funny how slightly older boards with the bigger TO-263-sized MOSFETs almost never had this issue. On the other hand, I see hot-running TO-252 MOSFETs all the time.

[Pentium4]

Re: The Hall of Shame - Badcaps Photo Montage

That's actually a classic transformer with a bridge rectifier (made out of 4 diodes) and the capacitor to smooth out the ripple.
The output voltage will probably be about 13-15v with no load.

I would personally use that transformer for some projects and replace the adapter with a cheap switching power supply - those classic transformers are more expensive sometimes compared to switching power supplies.

Okay, I'll switch it out with a cheap switching supply. That thing has a good sized transformer!

Not my image, also found it on the web, but failed 8mm 1000uF 6.3V Rubycon YXGs...



It looks like they're close to the northbridge and FETs, all of which were probably rather hot. I know enough heat can kill any 'lytic but 1000uF 6.3V capacitor failures seem to be very commonplace on motherboards.

In all seriousness, I've seen Delta do that a lot (mix Taicon, Ltec, and/or CapXon with Nichicon, Rubycon, and NCC capacitors, or just use all Ltec, Taicon, and CapXon).

Especially since the CPU looks like a Pentium 4/Pentium D. That northbridge chip would be getting pretty toasty

[Wester547]

Re: The Hall of Shame - Badcaps Photo Montage

Especially since the CPU looks like a Pentium 4/Pentium D. That northbridge chip would be getting pretty toasty

It looks to me like an LGA774 or LGA775 board so that sounds right.

I bet you it's the hot FETs that caused it. I've seen a lot of incompetent motherboard designs with that issue for various caps on the motherboard.

The Dell Optiplex GX270 motherboards have the same issue with 1 particular cap spot under the RAM slots. Anything will cook there, except maybe for Panasonic FJS. And even those may have failed but just not shown it. The hot MOSFET next to that cap spot runs so hot that it actually will cause a burn to your skin! So most likely, it is running at 70C on the case at the very least. I probed some MOSFETs on an ASUS socket 939 motherboard before (not sure what model, but it was in an Acer PC) with a thermocouple, and they were running 75C with the PC just idling. Probably ran even much hotter with the case closed and PC at 100% usage. Just the SB in that machine was running at close to 60C - of course because there was no heat sink on it. With just a simple aluminum heat sink with no fins, I was able to bring it down to 50C - and that's at max PC load.

Funny how slightly older boards with the bigger TO-263-sized MOSFETs almost never had this issue. On the other hand, I see hot-running TO-252 MOSFETs all the time.

Well, the Optiplexes just ran hot all around and would cook pretty much anything in them, especially with the vents clogged with dust. Many Socket 939 boards that had integrated GeForce 6100/6150 graphics did have burning hot northbridges and southbridges.

On the other hand, I'm not convinced all TO-252 FETs on motherboards run hot. Even when the room temperature is around 30*C, nothing in the old clamshell style Dells (a la 8200s) seemed to run hot at all except the Willamette CPU heatsinks at 100% load. The northbridge barely feels warm and even the heatsinkless south bridge doesn't feel hot at all or even warm, nor do any of the TO-252 or TO-263 FETs in there, or any of the 85*C Nichicon VR capacitors scattered around the board (nor the couple of 12.5mm 3300uF 10V NCC LXZs further down the board). The only capacitors that actually ran hot (around 55*C-60*C, I'd estimate) with 100% CPU usage were the three 12.5mm 2200uF 16V Nichicon PWs and nine 8mm 560uF 4V Nichicon NAs in the VRM high and low circuit respectively, but I think capacitors of that grade (PW being non-aqueuous and NA being truly solid polymers) can take that. Even the 220uF 25V Nichicon VR in I/O filtering and the ones around the northbridge don't get hot or even warm at all.

I guess that particular case design is really good at ventilating hard drives and ICs with a certain passage of airflow maintained (seeing as how the RDRAM runs cool with the case closed but with it open is too hot to touch), especially when the vents don't have any dust cluttering them. I would also guess that because older Socket 370 Pentium IIIs (and Slot 1 Pentium IIs) didn't run warm at all that neither did the FETs on those motherboards, especially since the northbridges didn't have heatsinks back then....

TO-252 FETs running hot might explain why a 10mm lacquer-coated 1000uF 16V Nichicon HD in the VRM input circuit of a D845PEBT2 ran too hot to touch (60*C+, hotter than any of the capacitors in the VRM output) at 100% CPU usage - there was a TO-252 FET right near it, and TO-263 FETs next to the other three 1000uF 16V Nichicon HDs in that circuit, and they didn't run hot. Go figure.

[PeteS in CA]

Re: The Hall of Shame - Badcaps Photo Montage

Not my image, also found it on the web, but failed 8mm 1000uF 6.3V Rubycon YXGs...



It looks like they're close to the northbridge and FETs, all of which were probably rather hot. I know enough heat can kill any 'lytic but 1000uF 6.3V capacitor failures seem to be very commonplace on motherboards.

I have little direct experience with MBs, but pocketing lytics with hot components on all sides is never a good idea. Between the nice short and fat traces from the MOSFET Source leads to (apparently) the caps and the nice beefy Source bond wires inside the MOSFET, the heat of the MOSFETs would have been conducted very "nicely" from the MOSFETs to the cap leads connected to the Source leads. Beefy traces and wires are good conductors of heat as well as of current.

In all seriousness, I've seen Delta do that a lot (mix Taicon, Ltec, and/or CapXon with Nichicon, Rubycon, and NCC capacitors, or just use all Ltec, Taicon, and CapXon).

Folks here have mentioned that Delta seems to have mixed mediocre with good caps successfully, and I have no reason to doubt their word. When I worked at Delta, Lite On was one of the brands whose quality I would not disparage (likewise Astec, and several others). However, when our 4YO Dell desktop (full-sized mini-tower) would not turn on after cycling AC power the culprit was a small Ltec cap in the +5V Stby or PWM start-up circuit in a Lite On P/S; and several Ltec O/P caps were swollen or had puked some of their guts (plus an OST that was at an odd angle that might have popped its bung); Lite On had also used a couple of Taicons, which showed no outer sign of having a problem. So mixing low quality caps with good or decent stuff is a bit of a sore subject with me. That Dell had polymer caps on the MB, and was not cheap (max RAM and HDD for when we bought it). It should have lasted at least another 2 or 3 trouble-free years.