testing caps less than 1uF

Collapse
X
Collapse
+ More Options
Posts
 
  • Time
  • Show
Clear All
new posts
  • shaunbt123
    Senior Member
    • Nov 2012
    • 119
    • uk

    #1

    testing caps less than 1uF

    Hi there can someone tell me if there is a way to test capacitors below
    1uF i have a peak atlas esr meter but the minimum it will read is 1uF.i recently needed to test some caps below this value.
    thank you.
    shaun.
  • mariushm
    Badcaps Legend
    • May 2011
    • 3799

    #2
    Re: testing caps less than 1uF

    Capacitors under 1 uF are usually ceramic or tantalum capacitors. You don't find often the problems electrolytic capacitors have in these types of capacitors.

    Those capacitors either fall short and burst in flames (tantalums) or fall short or most often crack open (in case of ceramics).

    So check for those and when in doubt, replace them.. you can purchase rolls of 5000 ceramic capacitors for 10-30$ so few people waste time checking 0.1uF ceramic capacitors.

    Comment

    • euromatlox
      Senior Member
      • Mar 2013
      • 60
      • Finland

      #3
      Re: testing caps less than 1uF

      Many cheap multimeters can read smaller capacitors, up to about a few microfarads. Also available are electric capacitance meters, which are better for capacitance only measurements (they can read very small pF caps and bigger uF caps too). There is also a pretty popular USB-powered measuring device for inductances and capacitances, see youtube video below.

      http://www.youtube.com/watch?v=cpxbwjDny0E

      Comment

      • Mrx3750
        Badcaps Veteran
        • Jul 2013
        • 311
        • USA

        #4
        Re: testing caps less than 1uF

        I have a capacitance meter. It doesn't test for ESR, but it reads capacitance from 200 pf, to 20,000 uf.

        Comment

        • PeteS in CA
          Badcaps Legend
          • Aug 2005
          • 3578
          • USA, Unsure of Planet

          #5
          Re: testing caps less than 1uF

          Adding to what mariushm posted, large form-factor SMT ceramic capacitors tend to fail leaky or short-circuit. The leaky ones can be tricky to diagnose, unless they are visibly cracked (burned through 1.5-2 man-days yesterday and the day before doing just that!). The shorted ones can be pretty nasty, suddenly glowing orange or cherry red when power is applied, sometimes severely damaging or destroying PCBs.

          Large form-factor SMT monolythic ceramic capacitors are evil! Necessary and unavoidable, but EVIL.
          PeteS in CA

          Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
          ****************************
          To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
          ****************************

          Comment

          Related Topics

          Collapse

          • momaka
            Seasonic B12 BC-550 – barely 2 years old and with BAD CAPS already!
            by momaka
            I know I've been a little scarce lately (like the last 2-3 years), but I'm still here and still doing my thing with fixing PSUs.

            For today's considerations, I have a Seasonic B12 BC-550 [A551bcafh] 550 Watt ATX power supply for you (click on links for full size images).

            https://www.badcaps.net/filedata/fetch?id=3591771


            https://www.badcaps.net/filedata/fetch?id=3591772

            It's a modern ATX unit with fixed (non-modular) cables and an 80-plus bronze certificate. Here's the label:

            https://www.badcaps.net/filedata/fetch?id=359177...
            03-12-2025, 03:42 PM
          • Paxman_Swede
            Identifying caps on an old Zoom 9000
            by Paxman_Swede
            Hello!

            I have two projects on my work bench. One is a friends dead JBL Xtreme speaker with a blown voltage regulator and corresponding bulged and shorted cap. That cap has clear markings so I know what replacement I need for it.

            The other project however is a whole different deal. It's a Zoom 9000 guitar effect from the 90th that has developed a devil hound howl when there is no input from the guitar. I'm guessing caps problem. So, since I don't really use this effect anymore I thought it would be a perfect project to learn on.

            I have studied the board and...
            01-14-2025, 09:51 AM
          • captain150
            Help with switching power supply caps
            by captain150
            I'm trying to repair two old VCRs, they both have bad caps. One has leaky ones, the other would barely run until I subbed in some caps from another power supply I had laying around (though they are the wrong values). This vcr works for an hour or two, but then the power supply starts whining and the picture gets lines in it. I didn't replace all the secondary caps, so another voltage might still be problematic, or the values I used are too far off.
            I've been on mouser and digikey but the options are a bit overwhelming. I just need some new ones that will work. They don't need to be top quality,...
            03-16-2025, 07:34 PM
          • Foetuss
            Gigabyte GA-6OXT :: caps question
            by Foetuss
            Good evening

            I recently aquired a rev 1.1 Gigabyte 60XT, and was suprised of the amount of leaking caps for a motherboard of the P3 era. Especially the way the 330µf caps seems like the housing discolored even.
            Now, there are some 3300µF 6.3V KZG series around the CPU. Would it be OK to replace them with something like EEUFR1A332 ? (Panasonic FR 3300µF 10V). Or was this board designed around very low ESR caps?

            But I was also suprised about the bigger boys, which are 330µF 25V.
            Could it be they used 25V caps because they were cheaper / available at that time?...
            02-11-2025, 12:22 PM
          • Bartoloni
            testing voltage of unknown SMD caps
            by Bartoloni
            usually i have to replace motherboard caps (0805 SMD) ...
            the most used (and usually shorted) is the 4.7 uF 25V (HP boards)

            i have a lot of donnor boards... and i take some caps (same size) i measure the capacity using 2 different multimeters (when CAPS are removed from board)

            when i found a 4.4 or 4.5 uF caps i place 19V at the sides and i watch if they blow...(or maybe just start absorbing some milliAmperes)

            i was sopposing that if the caps are not blowing the voltage can be 25 (or in some rare cases 50V) and i use them as a replacement for the bad...
            06-23-2021, 11:34 AM
          • Loading...
          • No more items.
          Working...