Given a DMM with Ohm range, I use this method: 1. select a low range, e.g. 200 Ohm or 2k. 2. connect a cap with known capacity to the positve and negative input lead of the DMM. For your caps I would take a 4700 or 10000 uF. Place a short over the black and red lead. Note: Most DMM have "+" at the black lead, and "-" poalrity at the red lead -- take care of this and check first for your DMM (e.g. with a seprate voltmeter). 3. open the short and check time in seconds (your wristwatch is fine for this) for the time it takes from 2 DMM diplay values: Example: I start time measurement at a display "1.000" and stop at "5.000". Note the time on a piece of paper, I refer to it as t3 ;-) 4. redo steps 2 and 3 with the unknown cap. Note time you get now: t4. 5. do the math: time noted from step 4 divided by time noted from step 3, result multiplied by your value of cap from step step 2: C_unknown = ( t4 / t3 ) * C_known. This works well for me for caps between 1000 and 100000 uF since many years in field service. Method fails for caps with high leakage current and/or shorts. Another circuit I use in the homebrew lab is a simple astable multivibrator (standard TL071 with discrete npn/pnp transistor follower just to get 100 - 150 mA output current capability): Since multivibrator frequency is 1/t, and t = const * R *C. When you choose R to useful value, the time t is directly in uF (as can be displayed on the digital freq/period counter switch to period time display). Note: differences beteween time for astable output in pulse or period ("high" resp. "low" voltage) gives a rough indication of caps leakage current. All you need is a lab pwr supply, digital multipurpose counter, opamp & a few transistors ;-)) If a component has shorted, the resistance across the terminals should be very close to zero on the most sensitive range (1x in your case). If a component has a short, there is direct electrical contact where there should not be. That is it acts like a piece of wire rather than what you want it to be (be that a resistor, transistor, capacitor etc.). The reason why you are getting infinite resistance when measuring the resistance of that resistor is because the range or sensitivity of your multimeter does not go all the way up to 3Mohm. To measure the resistance of that resistor you need to use a multimeter which has a 1Mx range. Essentially a MOhm range. However it could well be that your resistor does have infinite resistance (it is an open component) and needs to be replaced. An open component is a component that has failed and there is no electrical contact where there should be. Most likely the component overheated somehow and has physically cracked. That is the component is physically disconnected from the circuit. hello, I heard that Ceramic Capacitors rarely fail nevertheless how can one be sure? Is there a way to test them to know if they are good? Is it important to test these or not? Any help would be appreciated! Svar til forfatter Videresend Vurder dette indlæg: Text for clearing space Log ind, før du kan sende indlæg. For at sende et indlæg skal du først tilmelde dig gruppen. Opdater dit kaldenavn på siden Abonnementsindstillinger, før du sender. Du har ikke den krævede tilladelse til at sende. 2. sofie Se profil Flere valgmuligheder 12 Sep. 2005, 18:27 Nyhedsgrupper: sci.electronics.repair Fra: "sofie" Dato: Mon, 12 Sep 2005 10:27:21 -0700 Lokalt: Ma. 12 Sep. 2005 18:27 Emne: Re: How to test a Ceramic Capacitor? Svar til forfatter | Videresend | Udskriv | Individuelt indlæg | Vis oprindelig | Rapporter dette indlæg | Find indlæg fra denne forfatter you can test for shorts or leakage with a standard VOM or DMM and then check for proper capacitance value with a cap meter or DMM with capacitance feature.