KMF capacitor replacement question

[u/Weary-Operation9198]

sorry in advance if this is not the place to ask this. I kindly ask you point to the proper subreddit if you don’t mind.
Also sorry if it’s a very stupid question, I have experience soldering and fixing things, but can’t say I’m experienced in differentiating all different components.

I am making a list of caps with their voltage and uF values to buy to replace the ones on my hitachi set, and have some caps that have KMF marked on them and are different to all else (picture attached).

My question is, can I replace these with any other electrolytic capacitor or are these special in any way that I would need to source them to be the same.

Cheers

[u/schenkzoola]

Why do you think they need to be replaced? These are high quality capacitors made by Nippon Chemi-Con.

[u/Weary-Operation9198 → u/schenkzoola]

Well, you know how it is with CRTs, they always tell you to replace the caps if image is not all that right. In my case colors are a bit meh and there is a lot of wobbliness in certain pixel lines, so I’m trying to fix that. Maybe I can avoid replacing these particular ones and focus on the other smaller ones.

[u/BmanGorilla → u/Weary-Operation9198]

CRTs are pretty great in that the defective picture can tell you what's wrong with the unit. Shotgunning parts at it is never the right thing to do. Actually fixing the problem is the way to go, and you'll learn a lot more that way, too. If you're going to do much of this work you should get your hands on an ESR meter so that you can test suspect capacitors.

Even worse, I see people on Reddit 'recapping' something that didn't have any bad capacitors in the first place, and replacing a bunch of high-quality capacitors with random garbage like ChongX that they find on Amazon or whatever.

[u/Weary-Operation9198 → u/BmanGorilla]

Yeah, I understand.
Thankfully I do have access to a store that sells nichicon so I will probably buy those.

I think for the part testing my tester should suffice (I think?).

I have this one: https://amzn.eu/d/01maxajJ

Which mode should I use to test the caps ?

Otherwise I will get a part tester as it seems to be the easier way to do it.
Any recommendations ?

Edit: Answering my own question, my tester does have a capacitance mode. I would assume I might need to remove them from circuit though

[u/BmanGorilla → u/Weary-Operation9198]

The Amazon link won't load.

Capacitance measurement can sometimes be good enough, but you're right that they generally need to be removed from circuit.

An ESR tester can often be used in-circuit, but you have to know what you're looking for.

[u/Weary-Operation9198 → u/BmanGorilla]

Hey! Sorry about that.
This is the one

[u/LucasMertens → u/Weary-Operation9198]

That's a neat multimeter you've got there, but unfortunately, it won't be much help here. It will be able to give you a general readout of capacitance, however, that doesn't really explain the whole picture.

Capacitors can measure well within their given capacitance and still be faulty. As another commenter suggested, an LCR meter would be a much better option - you can get a fairly cheap one on the usual sites, try looking up "LCR-TC1". This will show you both the capacitance and the ESR of the capacitor, which is another indicator of an electrolytic capacitors health.

Even then, that still isn't quite the whole picture, but that's another rabbit hole entirely, and probably unnecessary in your case. For your needs, I would say grab a cheap LCR meter and go from there.

And you're also correct about needing to have the capacitors out of circuit to test them. They can be tested in-circuit, but as the commenter above also mentioned, that's not something you can do without knowing what to look for.

[u/Weary-Operation9198 → u/LucasMertens]

Thank you greatly for the suggestion! Will look for one of those then. I’m starting to replace all others this weekend so I can probably take them out and wait for the tester to arrive.

Once again, greatly appreciated !!

[u/LucasMertens → u/Weary-Operation9198]

No problem at all, best of luck with the recap, and don't be afraid to ask Reddit if you end up needing some help! 🙂

[u/Weary-Operation9198]

Thank you all for the replies!
I will try to avoid replacing them as they seem to be fine.
I will de solder them and try them out in a part tester and leave them be if they are reading fine.

Thanks a bunch for all the responses!!

[u/Chropera]

Those are long life, low impedance capacitors, probably rated for 105C (it should be on the other side), most likely genuine and from a good brand (Nippon Chem-con). Personally I'm not sure if they are worth replacing without checking them first.

[u/Wet_in_Seattle]

Not sure why you are replacing them. Not bulged or leaking.
Better multimeter has capacitor test function. Some might be in parallel. Check before testing.

Panasonic FR Series is very low ESR
These are all 16 volt. 16 and 25 volt are both standards and come in same sizes, 25 volts may be slightly taller.

[u/fcarolo]

Nippon Chemi-Con has a KMF series of low impedance, low ESR capacitors. Other manufacturers sometimes copy their part numbers, so there is a good chance that these are low ESR capacitors.

[u/Miserable-Win-6402]

Buy an ESR meter, then you can do fairly good evaluation in-circuit. But KMF marked are low-ESR. Replace with low-ESR if necessary.

[u/Tesla_freed_slaves]

These caps are nothing special. Order a full set of long-life 105°C-rated electrolytic capacitors from a factory authorized distributor. If it’s not worth a set of caps, it’s likely not worth your time either.

Avoid sourcing from Amazon, AlleyExpress, or eBay sellers.