Bilbo Posted May 26, 2017 Share Posted May 26, 2017 Just got a LPS from China and a cap blew when I switched it on. Can anyone help me identify the caps value & rating from the picture below? Link to comment Share on other sites More sharing options...
Nigel Posted May 26, 2017 Share Posted May 26, 2017 whatever the rating...maybe it was wrong. Just sayin'..... Link to comment Share on other sites More sharing options...
Bilbo Posted May 26, 2017 Author Share Posted May 26, 2017 That could well be the case. The circuit board says 1uF but I'm unsure of the rating. I've also not seen 1uM as a value as printed on the cap. Link to comment Share on other sites More sharing options...
pete_mac Posted May 26, 2017 Share Posted May 26, 2017 That's definitely a 1uf cap - the 'M' refers to a tolerance of +/-20% She's certainly gone POP!! 1 Link to comment Share on other sites More sharing options...
Bilbo Posted May 26, 2017 Author Share Posted May 26, 2017 (edited) @pete_mac I have a 1uF 400V cap I could replace it with. I gather that the original is a 100V cap so will there be any problem replacing it with a 400V cap? Edited May 26, 2017 by Bilbo 1 Link to comment Share on other sites More sharing options...
ngquan Posted May 26, 2017 Share Posted May 26, 2017 Hi , that looks like a clone of sigma 11 power supply , and i think it's bypass cap so yeah 1uf /100v. Certainly should be no issue with higher voltage rating as long as it fits the board. Quan 1 Link to comment Share on other sites More sharing options...
LogicprObe Posted May 27, 2017 Share Posted May 27, 2017 21 hours ago, pete_mac said: That's definitely a 1uf cap - the 'M' refers to a tolerance of +/-20% She's certainly gone POP!! Must have eaten something funny................... Anyway...........it's only the pin spacing stopping you from using a higher voltage. Link to comment Share on other sites More sharing options...
Zaphod Beeblebrox Posted May 27, 2017 Share Posted May 27, 2017 (edited) 21 hours ago, Bilbo said: @pete_mac I have a 1uF 400V cap I could replace it with. I gather that the original is a 100V cap so will there be any problem replacing it with a 400V cap? No problem at all, provided it fits. BTW: VERY unusual to see a WIMA cap fail like this, provided it is used within it's ratings. Are the Chinese counterfeiting caps now? Edited May 27, 2017 by Zaphod Beeblebrox Link to comment Share on other sites More sharing options...
Bilbo Posted May 27, 2017 Author Share Posted May 27, 2017 Thank you all for your assistance. I have fitted a 1uF 400V cap as the size can be accommodated on the board without any drama. Cheers 1 Link to comment Share on other sites More sharing options...
andyr Posted May 27, 2017 Share Posted May 27, 2017 (edited) 7 hours ago, Zaphod Beeblebrox said: No problem at all, provided it fits. BTW: VERY unusual to see a WIMA cap fail like this, provided it is used within it's ratings. Are the Chinese counterfeiting caps now? All the Wima caps I have, give the type - eg. 'MKP 10', 'MKS 4' or 'FKP 1'. So, yes - I would think this is counterfeit (as it doesn't mention a type). Andy Edited May 27, 2017 by andyr Link to comment Share on other sites More sharing options...
F18 Posted May 27, 2017 Share Posted May 27, 2017 Those are very old Wima film caps, most likely fkp2 or mkp10. Quality has to turned to **** with some of the Wima's production in China. Cheers, Link to comment Share on other sites More sharing options...
pete_mac Posted May 27, 2017 Share Posted May 27, 2017 2 hours ago, andyr said: All the Wima caps I have, give the type - eg. 'MKP 10', 'MKS 4' or 'FKP 1'. So, yes - I would think this is counterfeit (as it doesn't mention a type). Andy Andy, the smaller form-factor WIMAs don't have the model specified on the outer casing. Link to comment Share on other sites More sharing options...
LogicprObe Posted May 27, 2017 Share Posted May 27, 2017 10 hours ago, Zaphod Beeblebrox said: No problem at all, provided it fits. BTW: VERY unusual to see a WIMA cap fail like this, provided it is used within it's ratings. Are the Chinese counterfeiting caps now? They have been for years! https://www.theguardian.com/technology/blog/2010/jun/29/dell-problems-capacitors Link to comment Share on other sites More sharing options...
Guest Posted May 27, 2017 Share Posted May 27, 2017 Is that a decimal in front of the 1 on the case of the item? It looks too small to be a 1?F, more like a .1?F. Link to comment Share on other sites More sharing options...
Saxon Hall Posted May 27, 2017 Share Posted May 27, 2017 No problem at all, provided it fits. BTW: VERY unusual to see a WIMA cap fail like this, provided it is used within it's ratings. Are the Chinese counterfeiting caps now? There was a counterfeit Rolls Royce from China on display at the Frankfurt Motor Show a couple of years ago, so yeah I reckon. 1 Link to comment Share on other sites More sharing options...
andyr Posted May 27, 2017 Share Posted May 27, 2017 51 minutes ago, pete_mac said: Andy, the smaller form-factor WIMAs don't have the model specified on the outer casing. Well, I have some 0.1uF/63v Wima MKS 4 caps which do show this name ('MKS 4'). Their dimensions are 10 x 7mm - so I would've thought this is 'small form-factor"? (They are 2mm thick.) Andy Link to comment Share on other sites More sharing options...
Addicted to music Posted May 27, 2017 Share Posted May 27, 2017 17 minutes ago, Saxon Hall said: There was a counterfeit Rolls Royce from China on display at the Frankfurt Motor Show a couple of years ago, so yeah I reckon. Even the Chinese don't buy Chinese made if they can avoid it. Hence I never go shopping in China for Electronics. My bother in law gets all his iPhones and laptops from his nephew in HK. 1 Link to comment Share on other sites More sharing options...
pete_mac Posted May 27, 2017 Share Posted May 27, 2017 2 hours ago, andyr said: Well, I have some 0.1uF/63v Wima MKS 4 caps which do show this name ('MKS 4'). Their dimensions are 10 x 7mm - so I would've thought this is 'small form-factor"? (They are 2mm thick.) Andy I should have said 'some of'... my bad. I have a bunch of various values sitting here that don't have model references on them. Link to comment Share on other sites More sharing options...
bob_m_54 Posted May 27, 2017 Share Posted May 27, 2017 I'd check the ESR on the 3 electros too. From the way the sleeves have shrunk, they have been running in a hot environment, and it is a common sign that the ESR may be a bit high. Link to comment Share on other sites More sharing options...
Zaphod Beeblebrox Posted May 27, 2017 Share Posted May 27, 2017 10 hours ago, johnmath said: Is that a decimal in front of the 1 on the case of the item? It looks too small to be a 1?F, more like a .1?F. I thought that too, but I have some WIMA (genuine) 10uF/50V caps here. They are 17mm X 11mm X 6mm! Yes, TEN MICROFARD. Additionally, I would expect that if it was 0.1uF, then it would have been branded 100nF, which is standard nomenclature. Link to comment Share on other sites More sharing options...
Bilbo Posted May 27, 2017 Author Share Posted May 27, 2017 (edited) 1 hour ago, Zaphod Beeblebrox said: I thought that too, but I have some WIMA (genuine) 10uF/50V caps here. They are 17mm X 11mm X 6mm! Yes, TEN MICROFARD. Additionally, I would expect that if it was 0.1uF, then it would have been branded 100nF, which is standard nomenclature. The dimensions of the cap are as per your spec Zaphod and the circuit board has 1uF printed on it so that's what I went with. It's been running very cool for the last 15hrs so it should be right. The seller is sending me a replacement cap so at least they responded to the problem. 7 hours ago, bob_m_54 said: I'd check the ESR on the 3 electros too. From the way the sleeves have shrunk, they have been running in a hot environment, and it is a common sign that the ESR may be a bit high. Excuse my ignorance but what is the "ESR" on the 3 electrolytic caps? Also which "sleeves have shrunk" are you referring to? The big caps are branded "Nichicon" but I guess I should take that with a grain of salt too! Edited May 27, 2017 by Bilbo Link to comment Share on other sites More sharing options...
Bilbo Posted May 28, 2017 Author Share Posted May 28, 2017 OK - disregard the ESR query - Google to the rescue! Link to comment Share on other sites More sharing options...
bob_m_54 Posted May 28, 2017 Share Posted May 28, 2017 (edited) Haha, cool. Even though the capacitance may still measure withing spec, the ESR can still be high. With the capacitor sleeves, they look like they may have shrunk a bit. I have drawn circles on your pic to show where I expect the sleeves to extend to on a new cap. Note: it's not always the case that this means the ESR is high, but I have found it to be a reliable indicator that it may be, and warrants checking, if you have the means. Incidentally, in my business that I had repairing consumer electronics, apart from my multimeter, the ESR meter was the next most used piece of test equipment. Edit: I forgot to add, any signs of bulging of the tops, is a dead giveaway too. Edited May 28, 2017 by bob_m_54 Link to comment Share on other sites More sharing options...
Decky Posted May 28, 2017 Share Posted May 28, 2017 That is NOT a 1uF cap - that would be 20 times the size. That is a standard 0.1uF WIMA PP cap. If you look closer you will see a small dot in front of 1. Link to comment Share on other sites More sharing options...
Zaphod Beeblebrox Posted May 28, 2017 Share Posted May 28, 2017 4 minutes ago, Decky said: That is NOT a 1uF cap - that would be 20 times the size. That is a standard 0.1uF WIMA PP cap. If you look closer you will see a small dot in front of 1. Not necessarily. Read my earlier post. WIMA would label a 0.1uF cap as 100nF, as per European standards. Link to comment Share on other sites More sharing options...
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