/ News & Press / Video / Capacitor testing basics. Don't use a multimeter. Here is why.
Capacitor testing basics. Don't use a multimeter. Here is why.
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00:00:00.709 all right let's talk take a minute and 00:00:03.05000:00:03.060 talk about capacitor testing I see a lot 00:00:07.16000:00:07.170 of people testing capacitors with their 00:00:09.32000:00:09.330 regular multimeter which is okay but 00:00:12.16900:00:12.179 it's not going to tell you if the 00:00:13.99900:00:14.009 capacitor is stable or not for use it 00:00:16.97000:00:16.980 will tell you the max capacitance that 00:00:18.95000:00:18.960 the current capacitor that you're 00:00:20.84000:00:20.850 testing has and that is it it will not 00:00:25.64000:00:25.650 tell you the equivalent series 00:00:27.29000:00:27.300 resistance of the capacitor or if it's 00:00:29.72000:00:29.730 ready to fail what getting close to fail 00:00:33.04000:00:33.050 nothing it will tell you basically if 00:00:35.81000:00:35.820 your capacitor capacitance is in range 00:00:38.45000:00:38.460 I'm not going to get to scientific into 00:00:41.00000:00:41.010 how a capacitor works and how the ESI 00:00:45.35000:00:45.360 works you can google that there are 00:00:47.02900:00:47.039 plenty of videos out there way people 00:00:49.76000:00:49.770 can explain it way better than I can 00:00:51.43900:00:51.449 I'm try to keep these videos basic for 00:00:53.86900:00:53.879 everybody that watches my videos can 00:00:55.45900:00:55.469 actually benefit from the content 00:00:57.52000:00:57.530 alright so basically if you test your 00:00:59.75000:00:59.760 capacitor with a regular set a regular 00:01:07.48000:01:07.490 multimeter you will see trying to do 00:01:12.32000:01:12.330 this one hand is not easy 00:01:13.94000:01:13.950 you'll see that the capacitor shows 100 00:01:16.99000:01:17.000 microfarad or roughly 98.1 and that is 00:01:21.92000:01:21.930 what the capacitor is rated it is rated 00:01:26.35000:01:26.360 25 volts at 100 micro farad this is a 00:01:29.39000:01:29.400 pretty old cap this is probably 00:01:30.92000:01:30.930 something from the early 80s and it's 00:01:34.06900:01:34.079 been kicking around in my parts bin for 00:01:36.10900:01:36.119 decades so we're going to go put this on 00:01:39.71000:01:39.720 an ESR meter and show what it shows so 00:01:44.33000:01:44.340 basically have the blue ESR meter blob 00:01:46.78900:01:46.799 pocket was a kit you can assemble this 00:01:48.53000:01:48.540 at roughly around 100 bucks you can get 00:01:50.74900:01:50.759 these almost anywhere on eBay or Amazon 00:01:53.60000:01:53.610 or any way like that I don't like to 00:01:56.69000:01:56.700 follow this chart because it's very hard 00:01:58.42900:01:58.439 to follow 00:02:00.07000:02:00.080 no I have a chart that I printed out 00:02:01.93000:02:01.940 which is right here and basically at 25 00:02:08.98000:02:08.990 volts and 100 microfarad you should 00:02:12.37000:02:12.380 probably get no more than 0.5 0.5 ohms 00:02:16.96000:02:16.970 resistance anything higher than that and 00:02:20.91000:02:20.920 you just - chuck it in the barrel so 00:02:25.18000:02:25.190 let's see what we got here 00:02:31.44000:02:31.450 not bad it's point 4 4 but I know this 00:02:37.00000:02:37.010 capacitor has problems how do you test 00:02:39.28000:02:39.290 for that well it's not easy in some 00:02:42.75000:02:42.760 circumstances it takes a little bit of 00:02:45.66000:02:45.670 assistance of other another thing and 00:02:49.06000:02:49.070 that would be temperature you can freeze 00:02:52.63000:02:52.640 it and you can heat it you can actually 00:02:56.07000:02:56.080 heat it with either a hairdryer audio or 00:02:59.62000:02:59.630 rework station or something to that 00:03:02.67000:03:02.680 effect and you can also freeze it that's 00:03:06.94000:03:06.950 why they sell this freeze it stuff they 00:03:09.31000:03:09.320 used to call it Tec in a can and you can 00:03:11.77000:03:11.780 temporarily revive capacitors to see if 00:03:14.53000:03:14.540 it comes back to life sometimes they 00:03:17.94900:03:17.959 actually raise the capacitance I mean 00:03:19.78000:03:19.790 that raised the resistance so I mean it 00:03:22.30000:03:22.310 can work either way but typically you 00:03:26.11000:03:26.120 can temporarily get the capacitor work 00:03:28.03000:03:28.040 again while you froze it so you would go 00:03:30.25000:03:30.260 around your circuit and you would spray 00:03:32.17000:03:32.180 each capacitor and find where the fault 00:03:34.15000:03:34.160 is that's nice now I want to show you 00:03:37.57000:03:37.580 here what happens when you freeze this 00:03:39.67000:03:39.680 capacitor that's probably 20 years old 00:03:50.44900:03:50.459 alright one point six one point whatever 00:03:55.35000:03:55.360 ohms it's not a very stable cap now if 00:03:59.04000:03:59.050 you put this on this meter you will 00:04:01.11000:04:01.120 notice that let's put it back on this 00:04:04.71000:04:04.720 meter and you will see that we're at 95 00:04:12.99000:04:13.000 mics that's not bad any average person 00:04:16.11000:04:16.120 that measured this capacitor said is 100 00:04:17.81900:04:17.829 mic capacitor and I would just go with 00:04:19.92000:04:19.930 it but no I would not I would this is on 00:04:24.45000:04:24.460 the verge of of being a no-good 00:04:26.58000:04:26.590 capacitor I would not want to put this 00:04:30.09000:04:30.100 in any electronics that are going to be 00:04:31.71000:04:31.720 outside or gonna be heated up works heat 00:04:36.93000:04:36.940 it up in any degree so junk you know and 00:04:40.20000:04:40.210 your regular multimeter says it's good 00:04:42.63000:04:42.640 your ESS is something different at 00:04:45.06000:04:45.070 different temperatures well it might be 00:04:47.61000:04:47.620 within range of your might be in range 00:04:51.93000:04:51.940 at room temperature but what happens 00:04:53.37000:04:53.380 when the device heats up what happens 00:04:55.29000:04:55.300 when it's next to a power supply or heat 00:04:57.09000:04:57.100 sink this is the common fault of most 00:05:00.60000:05:00.610 electronics is these electrolytic 00:05:02.61000:05:02.620 capacitors and you will be replacing a 00:05:04.50000:05:04.510 lot of these and almost ninety percent 00:05:06.71900:05:06.729 of the time that I fix something is 00:05:08.46000:05:08.470 always a bad capacitor it's as simple as 00:05:11.55000:05:11.560 that 00:05:11.96900:05:11.979 and it's a cheap repair and it can make 00:05:14.52000:05:14.530 you a lot of money if you just know what 00:05:16.68000:05:16.690 to look for you can look for bulges in 00:05:18.71900:05:18.729 the back of the capacitors this is a 00:05:20.25000:05:20.260 lead leads coming out of both ends on 00:05:22.80000:05:22.810 this capacitor but you can most standard 00:05:25.17000:05:25.180 capacitors will have two leads coming 00:05:26.61000:05:26.620 out of one end and you'll have your top 00:05:29.04000:05:29.050 here with a couple slits in it and 00:05:30.87000:05:30.880 that's those slits are made to pop open 00:05:33.39000:05:33.400 if there's a buildup pressure in this 00:05:35.58000:05:35.590 capacitor from it dying it will look it 00:05:39.21000:05:39.220 will explode well not explode well some 00:05:41.43000:05:41.440 do explode but it will will start 00:05:43.40900:05:43.419 leaking electrical electrolytes all over 00:05:45.30000:05:45.310 your circuit board or the case that it 00:05:47.49000:05:47.500 is mounted in so it's just a little hint 00:05:51.02900:05:51.039 for the new you know the new guys on the 00:05:53.01000:05:53.020 block trying to get into electronics and 00:05:55.29000:05:55.300 trying to troubleshoot devices that you 00:05:58.44000:05:58.450 know sometimes you turn that radio on 00:06:00.33000:06:00.340 addy 00:06:00.81000:06:00.820 me play a CD player radio whatever it is 00:06:03.48000:06:03.490 that you're trying to prepare and it 00:06:04.80000:06:04.810 works fine and then an hour later to 00:06:06.75000:06:06.760 something going wrong with it and it's 00:06:08.07000:06:08.080 blinking or something's not 00:06:09.65000:06:09.660 malfunctioning or the sound sounds 00:06:11.76000:06:11.770 horrible you know you get a 60 cycle hum 00:06:14.37000:06:14.380 on the on the speakers and this is the 00:06:17.88000:06:17.890 most common problem why is the 00:06:19.80000:06:19.810 electrolytic capacitor is failing and 00:06:22.20000:06:22.210 sometimes when you test them with these 00:06:23.55000:06:23.560 normal multimeters they will not tell 00:06:25.41000:06:25.420 you that they can not show you the 00:06:27.75000:06:27.760 equivalent service resistance of the 00:06:30.06000:06:30.070 capacitor I hope this helps somebody and 00:06:33.05000:06:33.060 let me know if you want more videos like 00:06:35.49000:06:35.500 this I try to keep them as basic and 00:06:37.29000:06:37.300 simple as possible I do not want to make 00:06:41.01000:06:41.020 this too complicated for people that are 00:06:43.26000:06:43.270 just starting out alright we'll see in 00:06:45.99000:06:46.000 the next video
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