There are 3 types of SM caps, all with no markings Dark brown, medium brown, and light brown (almost white). How do you check these components ?. The colour is no help at all. It depends more on manufacturer than the value of the part. This is a situation where one really does need a proper schematic to know what is what. -( Why they cant be marked as resistors are, I really dont know.

I tried a digital cap meter and an ESR meter with mixed results. I found that most of the dark brown caps has less than 1 ohm ESR, while a couple had 18 to 20 ohms on my ESR meter. Many of the white ones had over 100 ohms. I think the dark brown ones are the higher capactance caps. I hate to have to unsolder some of these to check them, so I hope that some of the electronic techs will provide me with their methods of checking these caps.

ESR is mainly used for higher value caps (1uF). These SMT ones are almost certainly much lower. Assuming they are ceramics, then I think the possible failure mechanisms are either leakyshorted, or plain open circuit due to cracking. An ordinary resistance check (out of circuit) andor capacitance check are more useful measurements. I spent hours once debugging a faulty vertical output stage, which turned out to be an intermittent partial short in a 100pF SMT cap.

Or maybe it was _under_ the cap, it went away after Id removed the cap to test it. The cap measured good but then the fault tended to take an hour to appear anyway.