smd capacitor need so help under standing them for part look up! - Page 1
Forum section: electronics / beginners

author: sub2001zero
author_rank: Contributor
timestamp: January 17, 2020, 01:56:20 am
content: Hi everyone I need some help I working on my friends Nintendo watch. The screen fade out after a few min after put a battery. I found out it need a smd output converter cap i don't if I am saying that right I found out with one it was and I desolderer it from the board to take a read out. So this is where I need help I used a fluke 87v meter on ohm the smd read 8.- m ohm to 17.3 m ohm at the highest point is that right? I need help find a smd cap to replace it thanks!

author: Jwillis
author_rank: Super Contributor
timestamp: January 17, 2020, 06:13:07 am
content: The resistance won't tell much about the value of the capacitor. If you can borrow or find a multi meter that has a capacitance setting that would be much more helpful. If you can take a clear photo of the board and where it came from that would also be helpful.Some here may be able to determine a ball park value based on the surrounding components.

author: sub2001zero
author_rank: Contributor
timestamp: January 17, 2020, 04:16:39 pm
content: so i need a lcr meter

author: schmitt trigger
author_rank: Super Contributor
timestamp: January 17, 2020, 05:20:05 pm
content: An LCR meter would be best, but many newer DMMs incorporate capacitance measurements too.

author: sub2001zero
author_rank: Contributor
timestamp: January 17, 2020, 06:13:24 pm
content: I also have a fluke 289 will that help. What lcr meter I don't want to spend more then 200.00 I was look at the AT824 Digital LCR Meter or the DE-5000. What is your thought on this!

author: mikerj
author_rank: Super Contributor
timestamp: January 17, 2020, 06:26:38 pm
content: Quote from: sub2001zero on January 17, 2020, 01:56:20 amDo you mean 8-17.3 milliohms, or 8-17.3 Megaohms? Big difference! If you mean millohms then the capacitor is shorted out, which is not uncommon for MLCC capacitors if they have been cracked due to mechanical stress.The Fluke 298 has a capacitance measurement mode, but if the capacitor is shorted then you won't be able to read the correct capacitance back. If the capacitor is not shorted out and you are able to read it's capacitance, then why do you think the part is bad?

author: sub2001zero
author_rank: Contributor
timestamp: January 17, 2020, 06:59:05 pm
content: I test the cap for a short and has no short.I show a picture of the tester the M stand for Mega ohm right!101_6219bysub2001zero, on Flickr

author: Jwillis
author_rank: Super Contributor
timestamp: January 17, 2020, 11:52:18 pm
content: A capacitor that is fully charged will read open because of the very high resistance a capacitor has when charged. If want to test capacitor if it is working short the to ends of the cap .Test with an Ohm meter.The resistance will rise as it charges because the meter is applying a voltage during a resistance measurement .Low value caps will charge very fast .To fast to notice the resistance rising. High value capacitors will charge slower. You may even see the resistance rise as they charge. But the resistance will always go to infinite on a fully charged capacitor no matter what value it is . But it won't tell you the value of that capacitor.If you press the yellow button you should be able to toggle to capacitance testing. The symbol right of thesymbol is capacitance.Why an expensive meter like Fluke doesn't have mode or select written on the mode button baffles me .

author: mikerj
author_rank: Super Contributor
timestamp: January 18, 2020, 04:30:50 pm
content: Quote from: sub2001zero on January 17, 2020, 06:59:05 pmUpper case 'M' = MegaLower case 'm' = milli

author: sub2001zero
author_rank: Contributor
timestamp: January 20, 2020, 10:03:34 pm
content: Hi everyone thanks for the help I have a quick question. I want to get a good Lcr meter in the next few month. My question I have one of the cheap DIY LCR meter will that read smd cap I never try it! Will this get me by on fix the watch until i get a good one!