Capacitors Bloating from Sitting?

[jazzie366]

So I have an older Hifonics X1200.4, a 1200 watt, 4 channel car amplifier. Hifonics uses strictly chinese parts, and are made by Maxxsonics. They had a period where they were amazing, then went to shit, then back to amazing (albeit now super chinese). They aren't known for failing at all, they are made very well now. However, as I said they're made super cheap. So they have caps inside rated 2200uF 50V. The amp was used for about a year in HARSH conditions, I absolutely drove this amp way over the limit. However, in the car audio world, amps can get hot enough to burn the paint off of their chassis, this is normal for competition grade amplifiers.

Now I took it out of service about a year ago, fun was over. Couldn't bring myself to sell it though. So I came back to it, and it sounded a little funny. I opened the case, and... bloated caps? Not leaking (yet) but noticable bulge 5 out of 6! The brand of the caps is "R • M" (Yes, that s unicode). I've seen these in Logitech devices, never seen them fail like this though.

Is this natural for capacitors? If not, I'm just gonna assume it was because they're cheap. The amplifier also was run very hot while it was in service, if it was running for long periods, under high stress it could see temperatures above 160 degrees.

[stj]

Re: Capacitors Bloating from Sitting?

post some foto's

btw, if your going to drive amps that hard then you need fans blowing through them.
it's not just the caps, very high temperatures effect everything - even the soldering.

[Wester547]

Re: Capacitors Bloating from Sitting?

It's possible for any electrolytic whose electrolyte has decomposed (for whatever reason) to produce excessive hydrogen gas just by sitting in a sealed bag, unsoldered or desoldered, at room temperature. Capacitors bloat in storage for various reasons. Contaminated (unclean) raw materials is one reason. Excessive ripple current causing the cathode oxide layer to form is another. Heat will certainly accelerate the degradation of the internal chemistry and that was a factor in your case. Off the top of my head, GSC/Sacon/Evercon, Fuhjyyu, CapXon, Teapo, KZG/KZJ, and Rulycon/Jee are examples of some brands and series whose behavior is more or less defined by venting on the shelf.

[jazzie366]

Re: Capacitors Bloating from Sitting?

It's possible for any electrolytic whose electrolyte has decomposed (for whatever reason) to produce excessive hydrogen gas just by sitting in a sealed bag, unsoldered or desoldered, at room temperature. Capacitors bloat in storage for various reasons. Contaminated (unclean) raw materials is one reason. Excessive ripple current causing the cathode oxide layer to form is another. Heat will certainly accelerate the degradation of the internal chemistry and that was a factor in your case. Off the top of my head, GSC/Sacon/Evercon, Fuhjyyu, CapXon, Teapo, KZG/KZJ, and Rulycon/Jee are examples of some brands and series whose behavior is more or less defined by venting on the shelf.

Yeah that makes sense. One other thing though, didn't AsiaX make caps for "JEE" before? I've got a Ulta 180W bench psu that is entirely capped with AsiaX and JEE, while none have failed, it's definitely clear to see they are both the exact same coloring (bright yellow) with the only major difference being the branding.

[jazzie366]

Re: Capacitors Bloating from Sitting?

post some foto's

btw, if your going to drive amps that hard then you need fans blowing through them.
it's not just the caps, very high temperatures effect everything - even the soldering.

That was with an 8" fan running on the amp constantly. 160 degrees isn't anything special for this, however in terms of electronics it is. As for car amps, no.

[Wester547]

Re: Capacitors Bloating from Sitting?

Some members here have posted internal shots of PSUs where CapXon, Fuhjyyu, Koshin, and Teapo all have the same orange or yellow sleeves. I don't think it means they are the same brand. It was to my understanding that Fuhjyyu is AsiaX's parent company. What's even more interesting is that since 1995, according to Fuhjyyu's history, Teapo and Fuhjyyu actually worked quite closely to manufacture miniature crapacitors together. It would certainly explain the high failure rate of both brands.

If you can push the tops back down on those bloated caps, they haven't formed permanent pressure inside and the electrolyte simply expanded from excessive heat. If you can't, the electrolyte definitely broke down and outgassed.

[Topcat]

Re: Capacitors Bloating from Sitting?

I've seen a lot of capxon and UCC KZG &KZJ series die on the shelf. FWIW, I loved HiFonics car stereo amps back in the old school days (early 1990's). They were bulletproof back then!

[jazzie366]

Re: Capacitors Bloating from Sitting?

I've seen a lot of capxon and UCC KZG &KZJ series die on the shelf. FWIW, I loved HiFonics car stereo amps back in the old school days (early 1990's). They were bulletproof back then!

They're bulletproof again! They're made REALLY well now, like the components are running well below spec, however they are inefficient as hell, the X1200.4 has 120A of fusing, yet it only makes 600W RMS... Yeah their efficiency is really bad these days.

Edit: Before you say the fusing might just be overkill, there are YT videos of similar amps from them drawing almost 100A while making under 1kW.

[jazzie366]

Re: Capacitors Bloating from Sitting?

post some foto's

btw, if your going to drive amps that hard then you need fans blowing through them.
it's not just the caps, very high temperatures effect everything - even the soldering.

Attached.

[stj]

Re: Capacitors Bloating from Sitting?

if you linked another site - it wont work.
you have to upload foto's here.

[jazzie366]

Re: Capacitors Bloating from Sitting?

if you linked another site - it wont work.
you have to upload foto's here.

Was limited on android, edited and fixed. Also, that is after pushing it down about 1mm as that was recommended to try.

[kc8adu]

Re: Capacitors Bloating from Sitting?

those are shot.
find same or higher voltage/uf in same size in a quality brand.go taller if you have room.and pick the lowest esr.esp for the input caps.
digikey is the best place to look.

[Behemot]

Re: Capacitors Bloating from Sitting?

I wonder what's so great about device filled with crap caps? Obviously it is not overbuilt at all. Temps above 160 are hard to believe though, even most semiconductors won't survive that for long, not to mention all the caps.

If it's so very hot just add a fan, no?

[kc8adu]

Re: Capacitors Bloating from Sitting?

what more surprising is that it survived as long as it did using bottom bidder parts.
only worse use would be to bolt it to the sub box.
and yes i see them come in with parts broken off the board from that.

I wonder what's so great about device filled with crap caps? Obviously it is not overbuilt at all. Temps above 160 are hard to believe though, even most semiconductors won't survive that for long, not to mention all the caps.

If it's so very hot just add a fan, no?

[Behemot]

Re: Capacitors Bloating from Sitting?

What these crap makers need is decent reviewers to point how terribly bad these things are. There are few of us reviewing ATX PSUs with decent level of technical knowledge, but hell, other kinds of HW need that as well. Otherwise they won't ever stop making ships full of crap. Just look what happened to UPS market…(although to my surprise, the SMT750RMI2U I just have opened actually has few Chemi-Cons, and some of the remaining crap is at least Illinois Cap, possibly Sam-Young (formerly Samsung?) SS and few low-ESR OSTs…so that'll work some time too).