I found the bad cap, looking at replacements

[eccerr0r]

Re: I found the bad cap, looking at replacements

I would also have to mention that a lot of these startup caps, must be a low leakage type. Don't cheap out and use the cheapest one, and it's usually safe to go up in cap max voltage.

[Per Hansson]

Re: I found the bad cap, looking at replacements

I know but it might still be important to match whatever is there.
Case in point: https://www.badcaps.net/forum/showth...102#post666102

[stj]

Re: I found the bad cap, looking at replacements

5mm 47uf having "specs"? you must be joking - it's going to be a chang/chong/cheng-x type junk.

[Per Hansson]

Re: I found the bad cap, looking at replacements

Yup, as stj said you can't use general purpose caps here.
This would be good: https://www.mouser.se/ProductDetail/...c/EEU-FR1C471/

The small cap is the startup cap, it can be pretty important to match it's specs well.
So is there anything written on the caps to help identify them?
Perhaps you can take a photo from the opposite side?

P.S: You can't put caps on leads: it will completely fuck up the unit (it wont regulate well).

[stj]

Re: I found the bad cap, looking at replacements

you cant use EB series caps on a psu - you need low impedance.
that's why they ran hot.

try FR series.

[evilkitty]

I want to replace the low quality caps in the 5v 2a adapter my rpi uses (I did make sure it can do 2A, not sure how long it can handle it with how hot the 470uf caps get, but it did so with 0 vdrop; that test was done with 18awg wire soldered to the board, not over a micro usb plug)
it had 2 caps fail, both are 470 uf 16v, they are by far the hottest running component in the unit
they lasted about 1.8 years, i guess that is not bad for low grade caps but, they were under a 25% to 50% load and able to get passive airflow
given i want the longest lasting part i can fit get in there

since it only has 4 caps and none are quality brands i figure i will replace them all; i would like to keep the caps the same or smaller diameter and the height 17mm or less (if i can get much longer life i can put the cap on a wire [max 18 awg] and give it more space)
IF i am gonna pay $5 for shipping lets be sure i don't need new caps any time soon

CAP A: 400v; 10uf; 10mm Diameter; 17mm tall; 5mm lead spacing (appears to be fore 120V mains after being rectified)
CAP B: 25v; 47uf; 5mm Diameter; 12mm tall; 2mm lead spacing (idk what this is for)
CAPs C & D: 16v; 470uf; 7mm Diameter; 12mm tall; 3.5mm lead spacing ( these are dead, look to be for 5vdc regulation)
here is a picture of the board

so while i was search mouser i found this cap
https://www.mouser.com/Search/Produc...67-EEU-EB1A471
later i was thinking about the ripple current and thought what if this is not generated ripple it is a tolerance, after looking into that it sounds like it is a tolerance, and very low ripple current rating mean it will heat up more
so then i found this one:
https://www.mouser.com/search/Produc...250ELL471MH15D
Am i making a mistake?


BTW there is a issue i have been having, it may be a software issue, but it could be a noise issue in my power, on occasion i get a odd noise in my audio over-wise it is seems spotless, so if there is something i can do to make the output cleaner i would like to know; i have already tried using aluminum foil to shield stuff from power lines, i did manage to get a voltage measurement during this event and only saw a variation of 0.01v; so far nothing i have done has had any effect, i also tried a ferret core on my audio cable