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irritating maze capacitor value

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redorlando101

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Hi all. I need help. I have a board but I noticed it is missing a cap. Anyone know the value of the cap?
 

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Looks like a decoupling capacitor. Most of the time you can live without them.
 
Are u sure it broke off? Looks like it wasnt populated in the first place to me. Whats wrong with it btw?
 
Try 16v 4.7uf

Well I think i can make that out from this pic.
10v 4.3uf.png


Original image if you want it.

IMG-20171026-WA0004.jpg
 
Well it actually looks more like 10v 4.3uf but that's not really a common part so 16v upgrade and 4.3uf and 4.7uf wouldn't really hurt. So more likely a 16v 4.7uf as that's more common or even more safer 16v 47uf which is very common cap value.
 
well it's across the 5v line,
so anything less than 100uf is going to be pointless.
it's for power smoothing
 
i'm not wrong, i wasnt saying what it was - i was saying what it *should be* as an engineer.
you wont smooth much ripple with 47uf
 
I'm pretty sure it's there for the larger spikes rather than the ripple. 16v 47uf was what I would have put on there.
 
spikes are a form of ripple.
lets look at some datasheets.
 

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It's to decouple the +5v and its very close to the VCC/GND which is usually the best place to put it. Smaller caps is best for these sort of tasks. That's why you have 0.1uf caps all over your pcbs. No point if they didn't smooth right? Smaller caps are very good at high frequencies. Are you sure you're not thinking of power supply filtering caps that deals with lower frequencies? I wouldn't put a high cap on the +5v line anyway in case something goes wrong. Anyway, op has already found what he needs. Don't feel like giving lessons in electronics which I know next to nothing about.
 
so i think i need to explain something.

the .1uf caps are ceramic or film type.
they have a very low esr and therefore a high reaction speed.
they wont actually smooth much - which is why you have one on every chip usually.

electrolytics have much higher capacity but are slower to respond.
in older psu designs it was common to have an electrolytic with a ceramic under the board across it's pins.

* i'm a design engineer btw.
:P
 
companies make mistakes.
like putting silver plated chips into tin plated sockets!
those assholes - Atari,Taito and Midway being the worst, never heard of galvanic corrosion.
2 opposing metals in contact with each other forming an electrical current!

silver plated chips should be soldered in or fitted into gold plated sockets
 
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