First various URLs with images of the asked X2 capacitors:
https://www.technikundnatur.eu/revox-mehr/die-rifas.html
Mike's TRS-80 Pages
capacitor - Replacement cap (filter / choke) for oscilloscope power supply - Electrical Engineering Stack Exchange
Beware Rifa Class X Capacitors! - UK Vintage Radio Repair and Restoration Discussion Forum
https://www.eevblog.com/forum/chat/old-rifa-capacitors-and-a-disaster-story/
and
https://www.mikrocontroller.net/topic/170923
Why do these versions in particular fail so often (unfortunately often associated with very penetrating odors and very time-consuming cleaning of the environment - today happens on Linn's Brilliant SMPS) ?
Thank you for clarifying of this.
https://www.technikundnatur.eu/revox-mehr/die-rifas.html
Mike's TRS-80 Pages
capacitor - Replacement cap (filter / choke) for oscilloscope power supply - Electrical Engineering Stack Exchange
Beware Rifa Class X Capacitors! - UK Vintage Radio Repair and Restoration Discussion Forum
https://www.eevblog.com/forum/chat/old-rifa-capacitors-and-a-disaster-story/
and
https://www.mikrocontroller.net/topic/170923
Why do these versions in particular fail so often (unfortunately often associated with very penetrating odors and very time-consuming cleaning of the environment - today happens on Linn's Brilliant SMPS) ?
Thank you for clarifying of this.
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Replacing all Rifa PME271M capacitors is at the top my to-do list when refurbishing a vintage device. The failure mechanism has been described extensively on many places. The (epoxy?) case will degrade and crack, letting moisture inside. Thermal runaway will then cause the explosion as soon as the device will warm up. yet another instance of manufacturers selecting the wrong matherial because they failed to test aging.
I never liked metallized capacitors always prefer polypropylene film and tests done on EW came to the same conclusion .
On paper capacitors a deposit( very thin ) of aluminium is applied on heating -quote-
"a complex mixture of metallic oxides ,silicates and fluorides --when heated fumes are formed --under pressure of expansion --explosion !
As an ex mechanical/electrical engineer I can verify personally aluminium gives of a nasty smell when burnt -- ( cancerous if constantly inhaled ) .
On paper capacitors a deposit( very thin ) of aluminium is applied on heating -quote-
"a complex mixture of metallic oxides ,silicates and fluorides --when heated fumes are formed --under pressure of expansion --explosion !
As an ex mechanical/electrical engineer I can verify personally aluminium gives of a nasty smell when burnt -- ( cancerous if constantly inhaled ) .
To my knowledge, a formal failure analysis backed by real data has never been published because it would obviously be a lawsuit magnet. Rifa PME271M capacitors were also installed on older Shaffner EMC filters, they are notorious for this issue. As you already noticed, a quick internet search does list several forum threads and blogs. Deep inside a few of them, such as Let's Talk About Capacitor Failure - Byte Cellar , you will find some good insights about the vintage Rifa X2 capacitors. They are usually presented under the "anecdotal" and "iphotetical" light, again to avoid a lawsuit.
Rifa's MP caps are infamously notorious, but in reality all Metallized Paper caps eventually end in the same way sooner or later, even non-Rifa types.
It is just especially shocking for Rifa, which is (was?) a highly reputable manufacturer.
If you restore vintage equipment, one of the first thing to do with Ecap replacement is to remove paper caps and use a mylar substitute.
PIO types seem to be more durable
It is just especially shocking for Rifa, which is (was?) a highly reputable manufacturer.
If you restore vintage equipment, one of the first thing to do with Ecap replacement is to remove paper caps and use a mylar substitute.
PIO types seem to be more durable
This is very interesting, in around 2000 Ericsson bought Rifa which became Ericsson microelectronics and then two years later Infineon Technologies AG bought out Ericsson,s microelectronics which has factories in China -Indonesia -Malaysia -Singapore.
All this disruption occurred due to massive financial losses and large cut backs in the workforce , obviously the company being run by accountants rather than engineers .
I have in my hand a Rifa (old script style ) MP -0.47uf -275 volt AC capacitor , this made me test it out registering on my Wayne Kerr bridge at 0.29uf at 4.5 ohms ESR.
No sign of cracking but there again I got it out of an old BT mains conditioner so I don't think they would sell BT downmarket components.
Dielectric strength falls far short of PP film .
I don't use metallised anything in any builds or repairs I do .
All this disruption occurred due to massive financial losses and large cut backs in the workforce , obviously the company being run by accountants rather than engineers .
I have in my hand a Rifa (old script style ) MP -0.47uf -275 volt AC capacitor , this made me test it out registering on my Wayne Kerr bridge at 0.29uf at 4.5 ohms ESR.
No sign of cracking but there again I got it out of an old BT mains conditioner so I don't think they would sell BT downmarket components.
Dielectric strength falls far short of PP film .
I don't use metallised anything in any builds or repairs I do .
In this case this URL is also of interest:
Yamaha issues safety recall on amps, 30 years on | What Hi-Fi?
Yamaha A-760 | Hifi-Wiki
Restoration of a Yamaha A-760 vintage integrated amplifier
Catastrophic capacitor failure in Yamaha amplifier
Yamaha A -960 repair | Audiokarma Home Audio Stereo Discussion Forums
The mentioned RIFA versions were also here the reason for the performed safety recall (I have heard from one user, that still after 37 years a free repair service was carried out by Yamaha in this context).
Which claims for damages have been asserted against RIFA here at whole - this would be interesting to know.
Yamaha issues safety recall on amps, 30 years on | What Hi-Fi?
Yamaha A-760 | Hifi-Wiki
Restoration of a Yamaha A-760 vintage integrated amplifier
Catastrophic capacitor failure in Yamaha amplifier
Yamaha A -960 repair | Audiokarma Home Audio Stereo Discussion Forums
The mentioned RIFA versions were also here the reason for the performed safety recall (I have heard from one user, that still after 37 years a free repair service was carried out by Yamaha in this context).
Which claims for damages have been asserted against RIFA here at whole - this would be interesting to know.
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The Yamaha 30+ years warranty repair brings out an interesting difference between USA/UK and most EU laws. I am not an expert, but this is pointed out to EU manufacturing companies that also export to those markets. According to USA and UK legal system, the manufacturer is forever accountable for any serious damage due to preventable/known product faults - it does not matter if the accident does happen 1 or 100 years after the purchase. On most EU countries, and certainly in Italy, the issue is blurred and need to be resolved trough the legal system, but generally speaking after 10+3 years the manufacturer accountability is greatly reduced. Safety recalls for brand name decades old products are still rare due to the constant M&A activity of big companies; the firm that does own a brand today is almost certainly never the same legal entity that sold that product 20 years ago. In Japan this is not the case.
That could be quite true on the legal side ---in theory , but there is a world of legal difference between the good US Government public products protection policies and the UK spoken acknowledgement and actual actions where the UK public are rebuffed at every attempt .
Not so in the USA where I am in constant touch with the leading Class Action US website , don't take my word on this just ask the UK public when their domestic product breaks down in a short time .
As I still get emails from my last website I can account for 1000,s of complaints gone unanswered even when it blatantly obvious its a manufacturing fault.
Not so in the USA where I am in constant touch with the leading Class Action US website , don't take my word on this just ask the UK public when their domestic product breaks down in a short time .
As I still get emails from my last website I can account for 1000,s of complaints gone unanswered even when it blatantly obvious its a manufacturing fault.
in this case check out
http://cases.gardencitygroup.com/pdf/ABI/ABINotice.pdf
and post from 01-21-2005, 02:01 PM under
*** Class Action Lawsuit Against Abit *** - Badcaps Forums
Mainboardhersteller steht fur Elko-Ausfall gerade (Update) | heise online
and the history under
Capacitor plague - Wikipedia (English)
Capacitor Plague – Wikipedia (German)
- of the most famous issue concerning capacitors
under
https://dollybrtan.com.au/subhanallah-meaning-krzi/capacitor-plague-brands-bd430e
and
http://webcache.googleusercontent.c...brands+&cd=3&hl=de&ct=clnk&gl=de&client=opera
is also RIFA mentioned.
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Thanks for the information Tiebassuebertr , I read the German link although my German is terrible as well as the others .
Intel stopped making motherboards during the rise of Laptops in around 2013 and yes mentioned Taiwan.
My two computers are PC,s one has an "Intel " type board the newer one Gigabyte .
I just tested an old Jamicon -47uf-450 volt capacitor I had lying around ,it was down about 3uf but the ESR was 0.9 not bad for an electrolytic .
Thanks for the link to badcaps.net didnt even know it existed !
Intel stopped making motherboards during the rise of Laptops in around 2013 and yes mentioned Taiwan.
My two computers are PC,s one has an "Intel " type board the newer one Gigabyte .
I just tested an old Jamicon -47uf-450 volt capacitor I had lying around ,it was down about 3uf but the ESR was 0.9 not bad for an electrolytic .
Thanks for the link to badcaps.net didnt even know it existed !
I think not. Caps like RFT/Siemens MP and Russian MBGO, MBGT are all paper capacitors, but deeply impregnated within ceresin that doesn't crack.
But of course, these are closer to PIO.
