The Hall of Shame - Badcaps Photo Montage

[Heihachi_73]

Yep, "pfffffffffffffffffffffffff"

They look absolutely tiny, was this a 200W unit? Looks like something got a bit toasty in the bottom left of the second photo too.

(Replying to my own post above, aside from the two Fuhjyyu mains, the Thermal Master was full of JEE caps, surprisingly none have blown up yet).

[Dannyx]

Can't remember exactly what its power was, but it was worth fixing just for testing stuff, since it was just one cap at the end of the day

[Dan81]

Originally Posted by Dannyx

Can't remember exactly what its power was, but it was worth fixing just for testing stuff, since it was just one cap at the end of the day

It's a crappy noname 450W unit. I remember as I had one and it had anorexic heatsinks along with crappy ChengX caps and YongXing VZ primaries and it your picture matches exactly the description I gave.

[PeteS in CA]

Actually, that residue looks like dust. Unless a cap vented from the bottom, the residue is also too close to the PCB for the residue to have come from that cap that blew its top.

[Dannyx]

Or it came from the resistor just barely visible in the first pic, though it appears to be the cleanest part there. Certainly not dust as I remember the PSU was clean, so it couldn't have been dusty in just that small patch and of such white color. "PSU dust" tends to be brown

[Sparkey55]

Originally Posted by Dannyx

Found this in an ATX supply and I thought it might be interesting: not sure if that white "fog" is directly related to the bulged cap, but I believe it is, since I haven't seen anything like that so far...what is that ? Has anybody seen this before ? :| Does electrolyte "vape" like that ?

Most likely fine dust buildup from air flow (or lack of...) eddy currents.

[PeteS in CA]

The residue looks to me like it is deposited on wires nearest case vents, in a pattern that suggests the residue came from outside of the PSU.

As to color, over the decades I've seen a range of color shades, from light tan to medium brown. I suspect that folks who live in areas where the soil is red clay see reddish colored dirt.

[diamon]

@PeteS in CA: these vented caps from the bottom where in a Panasonic SC-PT 660 Home Theater System. I have seen much more of this brand (KZE) and popped (bottom or top).



I have replaced them with Panasonic FM ones, I always use Panasonic as replacement.

[momaka]

For Chemicon KZE to pop like that ^ , there must be something very VERY wrong with the circuit design they were in - either too much ripple current, poor ventilation, or perhaps voltage overshoot above rated voltage. These caps don't look counterfeit either, so it really has to be something with the circuit / device design to kill them like that. I bet the same thing will happen to the Panasonic caps a few years down the road.

[Wester547]

KZE is a series by Nippon (United) Chemi-con. They are usually known to be good capacitors. It’s the KZG (easy to confuse with KZE) and KZJ series that are known to be wholly unreliable. As with momaka, I’m guessing those KZE died by way of excessive heat.

[PeteS in CA]

Given the condition of those sleeves, I'd be concerned about hot adjacent components and cooling in that part of the unit. It's been almost 10 years, but I have tortured many KZEs, HEs, FMs, and ZLs to "death" (8X-10X rated ripple current, 22 hours a day, until the parts failed catastrophically). All four series (among others) performed well and similarly; NCC/UCC, Nichicon, Panasonic, and Rubycon are all good companies, producing - mostly - good products.

So if this Home Theater System is yours, I'd be careful about the environment in which you use it and keep an eye on those FMs. All four of the series I listed above use water-based electrolytes, and electrolytes of that type seem more sensitive to heat than non-aqueous solvent-based electrolytes (e.g. LXZ, PW or PA, or FC series).

For my part, 10 years ago was also two companies ago and I now have a different sort of job.

[PeteS in CA]

Originally Posted by momaka

For Chemicon KZE to pop like that ^ , there must be something very VERY wrong with the circuit design they were in - either too much ripple current, poor ventilation, or perhaps voltage overshoot above rated voltage. These caps don't look counterfeit either, so it really has to be something with the circuit / device design to kill them like that. I bet the same thing will happen to the Panasonic caps a few years down the road.

Originally Posted by Wester547

KZE is a series by Nippon (United) Chemi-con. They are usually known to be good capacitors. It’s the KZG (easy to confuse with KZE) and KZJ series that are known to be wholly unreliable. As with momaka, I’m guessing those KZE died by way of excessive heat.

Heh! We were all typing responses at about the same time. One thing diamon did not mention is the age of the home theater system. If it's 5 or more years old with lots of on time I'd be concerned about the environment in which it's used - stuff blocking airflow and cooling vents. Much under 5 years old and I'd worry about the internal environment - correct choice of part, adjacent hot components, poor airflow or convection path. If it has a fan I'd check that, too, though a bearing wearing out would be aurally obnoxious.

[dmill89]

Originally Posted by diamon

@PeteS in CA: these vented caps from the bottom where in a Panasonic SC-PT 660 Home Theater System. I have seen much more of this brand (KZE) and popped (bottom or top).



I have replaced them with Panasonic FM ones, I always use Panasonic as replacement.

Originally Posted by momaka

For Chemicon KZE to pop like that ^ , there must be something very VERY wrong with the circuit design they were in - either too much ripple current, poor ventilation, or perhaps voltage overshoot above rated voltage. These caps don't look counterfeit either, so it really has to be something with the circuit / device design to kill them like that. I bet the same thing will happen to the Panasonic caps a few years down the road.

Originally Posted by Wester547

KZE is a series by Nippon (United) Chemi-con. They are usually known to be good capacitors. It’s the KZG (easy to confuse with KZE) and KZJ series that are known to be wholly unreliable. As with momaka, I’m guessing those KZE died by way of excessive heat.

Originally Posted by PeteS in CA

Given the condition of those sleeves, I'd be concerned about hot adjacent components and cooling in that part of the unit. It's been almost 10 years, but I have tortured many KZEs, HEs, FMs, and ZLs to "death" (8X-10X rated ripple current, 22 hours a day, until the parts failed catastrophically). All four series (among others) performed well and similarly; NCC/UCC, Nichicon, Panasonic, and Rubycon are all good companies, producing - mostly - good products.

So if this Home Theater System is yours, I'd be careful about the environment in which you use it and keep an eye on those FMs. All four of the series I listed above use water-based electrolytes, and electrolytes of that type seem more sensitive to heat than non-aqueous solvent-based electrolytes (e.g. LXZ, PW or PA, or FC series).

For my part, 10 years ago was also two companies ago and I now have a different sort of job.

Agreed, it looks like the Panasonic SC-PT 660 is an HTIB (Hone-Theater in a box) system that is barely bigger than a DVD change but claims "1000W" (428W in the small print but still a lot for such a small system), and that is a lot of power (and this heat) in such a small case so it is no surprised that it roasted the caps (I'm honestly surprised none of the BGA chips have failed yet), and it will almost certainly roast the new ones eventually too, but given that it lasted nearly 10 years (looks like it was circa 2008-2009) the new caps will probably last until well after it is obsolete (or another component fails).

[PeteS in CA]

If diamon got 8 or 10 years of life out of those caps, that isn't too shabby, though the failure mode is visually dramatic. That system does look like it could be made part of a stack in a position that compromises airflow or convection. That would be a user issue rather than a design issue, of course.

[momaka]

Originally Posted by dmill89

Agreed, it looks like the Panasonic SC-PT 660 is an HTIB (Hone-Theater in a box)

Oh wait a minute, I missed that part!

I just serviced a SC-PT770 last month for some family friends - had a shorted MLCC near one of the class-D amp ICs. And this was actually the second time this has happened (first time was a little over 8 years ago).

Going by the pictures, that SC-PT660 looks very similar, if not identical.

With that said, I can tell you that the SC-PT770 has a small 50 mm fan on the back that provides cooling to the heatsink with the class-D amp ICs. The fan runs constantly when the system is turned On, but at a fairly low speed. There are filtering caps of the same specs as the ones diamon posted above, and they are sitting fairly close to the class-D amp ICs. In which case, I suggest to diamon to check the fan and make sure it works well.

I did a thermal check on the SC-PT770 that I was servicing, and the class-D amp IC heatsink didn't run to hot - just a little warm after normal listening volume with lots of bass output. Maybe 40-45C. The warmest heatsink was the one with the primary switch IC for the main PS - probably ran somewhere around 55-60C. But there are no caps near that primary heatsink.

Originally Posted by dmill89

system that is barely bigger than a DVD change but claims "1000W" (428W in the small print but still a lot for such a small system), and that is a lot of power (and this heat) in such a small case so it is no surprised that it roasted the caps

Yeah, I don't know about those ratings...

The SC-PT770 I worked on is also rated for 1000 Watts... of "music content", of course - whatever the heck that means.

But even the "428" Watts rating is ridiculous. Don't trust me? Let's look at the speaker drivers, then: the two tall skinny "tower" speakers contain one or two 2.5" cone tweeters (depending on model - the SC-PT770 has only one in those tall plastic towers... what a waste, right? ), the center channel also has 2x 2.5" tweeters, and the surround speakers also 1x 2.5" tweeters each. I've opened the above set, and these tweeter speakers are just your average 3-5W tweeters. Maybe 8W if you're an optimist (I'm not!) So if that system is to output 428W, most of that would have to be in the woofer... which is a 6.5" cone type with a 10" passive radiator. Now, I've seen 6.5" car audio woofers rated for up to 100-200W RMS, and they have huge magnets and weight a ton. The entire woofer box on this SC-PT770 with its cabinet does not come close to weighting what one of these car audio woofers would.

So yeah... no way the woofer can do that much power. I think even 100W is too optimistic for the woofer... but I've digressed very far now.

Anyways, the point is: that SC-PT660 system very likely won't consume more than 100 Watts of power on a normal basis, just like the 770 didn't after I serviced and tested it. And with class-D amp ICs, there would be maybe 10-15 Watts max. dissipated inside that box under high power output - which the fan should still handle easily if it works fine.

Originally Posted by PeteS in CA

Heh! We were all typing responses at about the same time.

LOL, that was funny, indeed.

Three people mentioning the same thing (that perhaps the caps were abused somehow) should throw a caution that there may be something wrong with that system. Thus, I certainly suggest diamon to dig deeper if he still has that system.

[diamon]

I did not make photo's of the board, but did find it with Google.
Replaced also those 22uv 100v caps, one was bulged and the others had a very high ESR and a low UF value.


The ventilation in this device is poor, not much airflow in it (I cleaned all the dust that was in it also the fan).
Home Theater System is not mine, I repaired it for a colleague and have no idea about the age or the history. I did advise him to unplug it from the 220V when it's not being used (no 220v switch available on the back) and not to stack anything on top of it.
The rated for 1000 Watts, for one split second I think. 1000 watts > PMPO power
The colleague confirmed the next day, that the problems are solved and it's working like it should.

I have an Onkyo TX-NR807 system, Onkyo has replaced the HDMI board under the extended warranty.
I don't use the standby option on this Onkyo and it's has plenty airflow (it's on top of a cabinet), so doesn't have any heat issues.

[madan1]

Thomas the Capacitor

[Behemot]

wut?

[madan1]

Originally Posted by Behemot

wut?

if this means that the gif is not accessible, here - have a zipped avi

[momaka]

Originally Posted by madan1

if this means that the gif is not accessible, here - have a zipped avi

Well, even that didn't work too good.
WMP complained of missing codec, as usual (but that's no surprise - who uses WMP anyways, right? ). Meanwhile, VLC complained the file is corrupt/broken, but gave me an option to try and "repair" it. It sort of worked - saw a few frames with a tantalum cap puff some smoke. So I got the joke about "Thomas the Capacitor" now!

BTW, this forum converts all GIF files to JPG, so that's why the GIF didn't work.