Sacon FZ revival experiment

[momaka]

So after using capacitor bungs to repair the rubber feet on two laptops, shown here:
https://www.badcaps.net/forum/showpo...&postcount=548
… and here:
https://www.badcaps.net/forum/showpo...&postcount=585
… I was inevitably left with some paper rolls and cans from the Sacon FZ capacitors I “sacrificed”.

The paper rolls from these Sacon FZ caps looked absolutely bone-dry. The idea then occurred to me: what if I put a few drops of water on there? How (if at all) would that affect these already-failed capacitors?

So here it goes. First, this is how one of these bad Sacon FZ caps (in this case, rated for 16V and 470 uF) measured on my GM328 tester: no capacitance, infinite ESR… just completely open-circuit as far as the GM328 was concerned.
Sacon FZ experiment (1).jpg

But then, after adding a drop of water… ta-da!
Sacon FZ experiment (2).jpg

It’s not open-circuit any more!
Is this magic or what?!
Sure it still has a super-lousy ESR of 1.4 Ohms and a whopping V_loss of 17%... but it’s not open! As far as the capacity goes, it’s almost in spec… for the next lower capacitance size (330 uF) . Well, better than nothing.

Now, of course that doesn’t mean you can just add a little water and expect these caps to work again. I already tried that, though not in any device. As soon as I connected a voltage source on the cap (I can’t remember if 12V or 5V… but it was likely the latter), bubbles started oozing from the paper roll, suggesting the water was probably breaking down into Hydrogen and Oxygen (and the latter likely reacting with the aluminum foil to form a thicker oxide layer… or who knows?) In any case, the leakage current was horrendous. I forgot to note down exactly what I measured, but it was something in the range of 10 mA or so. It didn’t seem to go down much over time either, suggesting the water would probably dry out again, leaving the cap open once more.

And for more giggles, I also connected the cap backwards on my voltage supply for a few moments, just to see what would happen. Strangely enough, almost nothing changed – the cap roll still oozed bubbles / gas, if ever so slightly more. I then connected the supply back the normal way and left it there for a few moments. After this, I tested the cap once again to see if I did any damage:
Sacon FZ experiment (3).jpg

Well, looks like I didn’t change anything much with the voltage charging/discharging and reversing. The capacitance did decrease a little… as did the V_loss (leakage.) The ESR, on the other hand, was still sitting at a steady (and lousy) 1.4 Ohms.

And that was meant to be all I did with this experiment back then. But now come time to post it, I figured why not dig out that particular cap and see how it’s doing. After roughly half a year stored without a bung, this was it:
Sacon FZ experiment (4).jpg

So it didn’t go completely open-circuit this time, but lost nearly all of its capacitance again. Seems like V_loss goes with the capacitance hand-in-hand, though, as that has gone down too.

I then proceeded to add a drop of (hot) water again, and once more this Sacon FZ rose from its grave.
Sacon FZ experiment (5).jpg

As you can see, the capacitance was almost back to what it was 6 months ago (just slightly lower), while the V_loss was in the teens %. On the other hand, look what the warm/hot water did for the ESR: 560 mOhms now. -WOW, almost worthy of being general purpose! /sarcansm

Since I forgot to measure the current draw last time while the cap was connected to a voltage source, I did remember to do it now. With a 9V battery, the leakage current of the cap peaked at around 12-14 mA and then steadily decreased and stayed at 8 mA. After noting down the measurements of the leakage current (~2-3 minutes with the cap connected to the battery), I then checked the cap once again on the GM328.
Sacon FZ experiment (6).jpg

It seems like we have fairly repeatable results here… or at least with this particular cap. Both capacitance and V_loss decreased again, like last time. ESR did increase slightly, but that’s probably due to the warm water cooling off. All in all, though, it seems water can revive Sacon FZ caps for a short amount of time. I actually remember now I tried this many years ago, again with Sacon FZ. But I didn’t have an ESR meter back then, so I couldn’t report any results. All I remember is I had a Sacon FZ connected as a coupling capacitor on an audio circuit, and it wouldn’t do anything (which I expected.) Then I added a drop of water and… sound sprung out of the circuit!

Now this may raise the question: can this method here be used on something like a motherboard or video card with these Sacon FZ caps (if busted/bad) to perform a quick hardware function test on the device (under a minute)? My guess is: MAYBE. At least, with Sacon FZ it seems like it might be possible… though I don’t recommend it. My first such experiment goes even further back with CapXon - they remained dead / unaffected by the water. So YMMV. Of course, this experiment was purely conducted because I can’t let dead things be dead in peace, especially these FZ c[r]aps.

[eccerr0r]

I figure most caps that go to 0µF if they dry out, and simply adding water won't mix or restore the electrolyte back to what it was...even if what it was was any good.

One thing that one might try for fun is instead of water... use a mixture of glycol and water. Not sure if this will help any but would be an interesting experiment. (Glycol is typically used in caps from the start and is usually what gives the smell...) However this will not restore the life of the capacitor either. Perhaps with the glycol the loss might be reduced than with just water alone. BTW: are you using distilled water I hope?

All trying to restore the magic smoke in capacitors...

[stj]

try IPA and water - to thin it down.

btw, your going to have the chinese "rejuvenating" old caps with syringes with this thread!

[momaka]

Originally Posted by stj

btw, your going to have the chinese "rejuvenating" old caps with syringes with this thread!

Ah crap, you might be right!
I only created this thread as a joke, since I haven't seen anything silly like this done before... but now that I think about it... joke might come back on us.

So hide thread in VIP and block all Chinese IPs from accessing it? (Well, I suppose that might not do anything either, given VPNs nowadays... which Chinese citizens probably have to use anyways to access "Western" parts of the interwebs.)

Originally Posted by stj

try IPA and water - to thin it down.

Nah, ain't going to waste precious IPA on this stuff, LOL. Would rather use it for cleaning electronics stuff... or even drink it instead.

Originally Posted by eccerr0r

One thing that one might try for fun is instead of water... use a mixture of glycol and water. Not sure if this will help any but would be an interesting experiment. (Glycol is typically used in caps from the start and is usually what gives the smell...)

Interesting, didn't know that.
Isn't glycol considered a VOC agent?
And even if not, I probably shouldn't be snorting gases from Sacon FZ anyways. They honestly smell like cat piss when they sit in my junk box (used salsa container, lol) for a while - probably because they were made with cat piss to begin with.

Originally Posted by eccerr0r

However this will not restore the life of the capacitor either.

Yeah, more than likely it won't indeed.
On at least half of the caps I see go bad, I think the electrolyte just starts to attack the aluminum foil in the roll, and then from there it's just a downhill... hence the loss in capacitance and increase in ESR eventually to a point of no return.

Originally Posted by eccerr0r

BTW: are you using distilled water I hope?

Nah, that's too fancy for Sacon FZ caps.
First time around, I used tap water straight out of my bathrooms sink... which sees some of the worst lime scale build up in the pipes. So I imagine it's was full of contaminants... err... sorry, I meant electrolytes.

The second time around, I had a pot of hot water near my bench (with a dishwasher heating element inside - my ghetto-rigged humidifier/room heat booster ), so I used water from that. But i get the water from the bathroom again, so that pot of water was probably no better in terms of lime scale and sodium content. Actually, it's probably worse, since I've been evap-ing the water from the pot for a few days. I just changed it out today, as it had a thick layer of white stuff on the sides of the pot and on the heating element. Calgon could make a helluva commercial with the hard water we have here.

Originally Posted by eccerr0r

All trying to restore the magic smoke in capacitors...

All in the name of science, as Photonicinduction would say.

I also popped one of these Sacon FZ caps about a year ago and recorded the sound + video. Should probably upload it here someday for laughs. I've actually had a few even more sinister ideas of how to pop these badly.

[eccerr0r]

Well it doesn't need to attack to the aluminum to reduce capacitance though it certainly helps. Not having any electrolyte will invalidate that bit of foil anyway.
Having the wrong electrolyte will just leak charge away so probably shouldn't add any additional electrolytes into the solution.

And please don't drink IPA... unless it really is an ale, then you definitely don't use that on electronics... I'm not even sure you should stick isopropanol into the electrolyte, vapor pressure would increase. Glycol is organic but not a VOC, it's vapor pressure is lower than of IPA.

[Agent24]

Originally Posted by momaka

I probably shouldn't be snorting gases from Sacon FZ anyways. They honestly smell like cat piss when they sit in my junk box (used salsa container, lol) for a while - probably because they were made with cat piss to begin with.

Sacon FZ are so crap, they probably use fake cat piss.

[stj]

but FZ have high quality cans, the top vent ALWAYS works.

[momaka]

Originally Posted by stj

but FZ have high quality cans, the top vent ALWAYS works.

Only when they bother to put it!



Picture taken from my eVGA GeForce 6200 thread here:
https://www.badcaps.net/forum/showth...highlight=6200

[eccerr0r]

Dang... I was sticking stuff from my bag of cat piss into my avrtransistortester (dang i thought i had a gm328a, guess not, dont have any model printed on mine it seems) and a bunch of them made it go bonkers... hmm hope it didn't go bad or break transistortester. Some made my screen go wonky. Weird.

Anyway a lot of them end up being "No, unknown, or damaged part" surprisingly enough. Capacitors were so bad...

At least going back to my known or assumed good cap pile things went back to normal.

[Per Hansson]

Originally Posted by momaka

They honestly smell like cat piss when they sit in my junk box (used salsa container, lol) for a while - probably because they were made with cat piss to begin with.

Hahaha, good one!

Originally Posted by eccerr0r

Dang... I was sticking stuff from my bag of cat piss into my avrtransistortester (dang i thought i had a gm328a, guess not, dont have any model printed on mine it seems) and a bunch of them made it go bonkers... hmm hope it didn't go bad or break transistortester. Some made my screen go wonky. Weird.

I'm sure you are aware of it but the component tester can't take more than 5v on its pins.
So make sure to completely discharge capacitors before test, even if they have been in a drawer for a long time.

[momaka]

Originally Posted by Per Hansson

I'm sure you are aware of it but the component tester can't take more than 5v on its pins.
So make sure to completely discharge capacitors before test, even if they have been in a drawer for a long time.

^ This!

I almost messed up my tester a few times after trying to check caps that I have reformed. Seems they can take a bit of an abuse, though... but certainly not safe to do. The one that scared me was when I put in a 25V cap charged to about 15-ish volts. It was a large cap too (2200 uF.) Tester didn't appreciate it but also luckily didn't die.

So now I've made it a habit to always short out the leads on any capacitor prior to inserting it into my tester... and so far so good.

[stj]

the atmel usually survives, but you short the protection diode pack - i'v done it

on the bright side, the chinese sell the diodes on a strip of 10 for a $

[goodpsusearch]

Originally Posted by stj

try IPA and water - to thin it down.

btw, your going to have the chinese "rejuvenating" old caps with syringes with this thread!

quick, let's move this to VIP before it is too late

Originally Posted by momaka

So hide thread in VIP and block all Chinese IPs from accessing it? (Well, I suppose that might not do anything either, given VPNs nowadays... which Chinese citizens probably have to use anyways to access "Western" parts of the interwebs.)

Oh, I am late, you already thought of it


Let's also stop this experiment before we get zombie cap apocalypse please

[AleXis6]

please advice: "V_loss" corresponds to what parameter in the datasheet?
I have a couple different "transistor testers" and can't fully understand what this "V-loss" tells.

[AleXis6]

Originally Posted by momaka

I almost messed up my tester a few times after trying to check caps that I have reformed.

I did it couple times with 2 different testers (LCR T4 and LCR TC1).
It is more or less easy to repair -change the processor and write a new firmware (if it is available for your device).
and one time from mentioned 2 I also changed a diode pack.
device for flashing firmware is very chip I ordered it from aliexpress
available firmware you can find here https://disk.yandex.by/d/yW8xa5NJgUo5z

[eccerr0r]

The v_loss number doesn't quite match any parameters, just that higher is bad. It's related to leakage.
I pretty much toss any cap that's more than ~3% but that's just a wet finger guess. Even 3% is not great.

Incidentally, it was the capacitors in my refuse capacitor pile, not the pile I keep of "good" or "probably good" capacitors. And yes should always short the capacitors before testing, though I think the wonky behavior was due to me disturbing the display when removing the tester from the case to look for a model number...

I reform on my Sencore... and that I don't do very often.

[kevin!]

I did that same experiment with a condenser that shot out the aluminum part, I added water, I put the part of the roll where the plates are located inside the aluminum can, I sealed it, and it maintained the capacity of 300 microfarads of the 400 reais.
But having a water composition much higher than the original formula, it began to lose capacity over time, the plates corrode.

[Per Hansson]

Originally Posted by stj

the atmel usually survives, but you short the protection diode pack - i'v done it

Not all testers have any protection, mine don't, I didn't kill any of them yet though

Originally Posted by AleXis6

please advice: "V_loss" corresponds to what parameter in the datasheet?
I have a couple different "transistor testers" and can't fully understand what this "V-loss" tells.

Maybe this message by Madires can be of some help, but remember this is still leakage at low voltage, not the same as leakage at full rated voltage...
https://www.eevblog.com/forum/testge...75/#msg1726775

[momaka]

Originally Posted by AleXis6

I did it couple times with 2 different testers (LCR T4 and LCR TC1).
It is more or less easy to repair -change the processor and write a new firmware (if it is available for your device).
and one time from mentioned 2 I also changed a diode pack.
device for flashing firmware is very chip I ordered it from aliexpress
available firmware you can find here https://disk.yandex.by/d/yW8xa5NJgUo5z

That's the thing - I dislike doing any kind of firmware/BIOS programming. Don't know why, but I've never had good luck with messing around with digital circuits, so I stay away from them. The analog/power side of things is where I like to be.

Originally Posted by eccerr0r

The v_loss number doesn't quite match any parameters, just that higher is bad. It's related to leakage.
I pretty much toss any cap that's more than ~3% but that's just a wet finger guess. Even 3% is not great.

You might be wasting some good caps then.
These cheap meters don't always seem to read the V_loss / leakage current properly. For example, yesterday I was recapping a worthless 15" LCD monitor with spare/leftover crap caps that were pulled during preemptive recaps. I had one CapXon KF read relatively low on V_loss - about 1.5-2%... or within what my meter regularly shows for most "OK" caps. Then I also checked a similarly rated CapXon KM (CapXon's general purpose series) and it showed about 5%. So I figured the KF was in a better shape than the KM. Before installing it into the circuit, I decided to do a quick reform with 12V (both caps were rated for 25V) but without any series resistor - just connected straight to a 12V power adapter. The 12V power adapter I was using likes to whine when it's unloaded and the pitch of the whining will change with very light loads. So when I hooked up the CapXon KF, I could literally hear how it took a few seconds for the cap to reform, given the load it was pulling from the adapter. And to further check on that, I connected a multimeter in series with the cap and measured the current. Eventually, the KF settled to about 8-9 uA of leakage current... but it took a good minute or so to get there. In contrast, the CapXon KM charged up instantly and was only showing about 3-4 uA of leakage.
Then here is where it gets interesting. I had a Teapo SC rated for 35V and 330 uF (just slightly higher than that of the CapXon KM and KF, both of which were 25V, 220 uF parts.) The Teapo SC also showed low V_loss on the GM328 meter - I think 2.5% or thereabouts. But get this - trying to charge that Teapo cap with the same adapter, I could hear it was pulling much higher current, based on the adapter's whining. And sure enough when I checked the current with a multimeter in series, the Teapo SC was drawing about 120-130 uA - roughly 10-20x higher leakage current than the CapXon KM or KF... and didn't want to settle to less than 100 uA even after a few minutes. As soon as I removed the Teapo cap and checked the voltage across it while sitting disconnected from the adapter for ~10 seconds, the voltage across it was only 9V. So it's quite terribly leaky. The KF and KM maintained about 11V for at least a few minutes after being disconnected from the adapter.

So in short: don't trust those cheap meters to measure V_loss correctly - they simply don't test at a high enough voltage to show any potential problems (pun intended.) When in doubt about leakage current, best way is to bring out a PSU, charge the cap and monitor the leakage current after a few minutes. If it's still high, the cap is probably going to go bad at some point sooner rather than later - at least when it comes to crap cap brands. With good Japanese cap brands, you may find high leakage current for the ultra-low ESR series, and that's fairly normal (most of my salvaged Rubycon MCZ stock from Xbox 360 motherboards regularly reads 3-5% V_loss on the GM328... but they've been doing OK for many years now.)

Originally Posted by kevin!

I did that same experiment with a condenser that shot out the aluminum part, I added water, I put the part of the roll where the plates are located inside the aluminum can, I sealed it, and it maintained the capacity of 300 microfarads of the 400 reais.
But having a water composition much higher than the original formula, it began to lose capacity over time, the plates corrode.

Cool!
So it looks like we are getting to the same results.

[AleXis6]

Originally Posted by momaka

So in short: don't trust those cheap meters to measure V_loss correctly

thanks
I have the same opinion