I found the bad cap, looking at replacements

[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

[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.

[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

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

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

[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.

[jazzie366]

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.

All those caps are fake Chongx or Chengx caps. The print is wrong, there is no series denotation and there is no lot number. They're blatant fakes. I've found fake ChengX/ChongX etc in many power supplies that were branded and UL listed etc. Obviously they were lower end ones, but nonetheless they'll still make it.

The fakes fail a lot sooner than the real ones, Chong and ChongX are spinoffs of the actual caps ChengX and Chang which ChengX being made by Bentex and Chang being made by Yang Chang.

Oh yeah, keeping in mind that they're fake. I found out fake caps are usually highly deprived of electrolyte. They reduce the amount to reduce costs, this is easily seen by taking a fake and a real and opening the fake one and the real one. The real will have much more electrolyte than the fake. The fakes also commonly have a very clear, (sometimes) odorless electrolyte.

[NeedsMoreFlux]

Re: I found the bad cap, looking at replacements

I think if you use caps that are physically larger then they will be able to handle more current with less heat.

[NeedsMoreFlux]

Re: I found the bad cap, looking at replacements

I know others on here disagree, but I don't think it matters which brand you use. especially on cheap chinese parts like this.

[stj]

Re: I found the bad cap, looking at replacements

your wrong because the idea is NOT to have to fix it again later.
i would use a 47uf 35v/50v panasonic FR in it.

[evilkitty]

Re: I found the bad cap, looking at replacements

@stj you hit the nail on the head with the brand part (Changx)

I have 2 questions about the series
1. do you have a link to what each means/ intended use
2. which series do i want for each cap

I do have 3 of these units (replacing caps in all), 2 have the same garbage caps, one has different caps, the other has Jwco, the larger 10uf caplooks to have a actual number on it (CD11G brand appears to be jw)

I have not replaced any caps yet, all i did was swap a in a spare board
the original caps run hot, but to be far the adapter puts out 5.25v and i used 2.4 Ohms (5 Ohm 10% 10W x2) resistance and it did maintain 5.25v and it is rated (more accurately labeled) at 2A
we all know anyone using knockoff/fake caps does not care how long the unit last

I want to make sure i get the correct/best caps

@Per Hansson
After looking at that cap, wouldn't this one be better/last longer?
https://www.mouser.com/ProductDetail.../EEU-FR1E471Y/

@stj
as for the 47uf cap, this is the only one matching what you would use:
https://www.mouser.com/ProductDetail...67-EEU-FR1H470
It is a tad wider but i think it will fit

and about that 400v cap, does that need to be fr as well?
i had this in my cart, i know it is only rated at 160v, but it should only be getting used at ~125v
https://www.mouser.com/ProductDetail...47-UCA2C100MPD

[kaboom]

Re: I found the bad cap, looking at replacements

Check temp rise on that little transformer- bet it's cookin' at 2A out w/o the PCB in the enclosure.

Sorry to say that looks like lots of cheep "fone chargers" I've EOLed. That has potential to kill if the transformer overheats and shorts pri-sec. It'll keep working with 5V across the output leads while line voltage is present to external GNDs, including YOU.

R- PI is the next frontier in cheep POS supplies, after gray/black market tablets/ fones & aftermarket chargers.

[evilkitty]

Re: I found the bad cap, looking at replacements

the transformer seemed warm, but those 470uf caps were cookin and it was not a very long test, maybe 60 seconds
for actual use this board is only outputting 0.5A and at most 1A or 0.5+ what ever it takes to charge a old 2ed gen ipod shuffle

[budm]

Re: I found the bad cap, looking at replacements

You cannot go wrong with PANASONIC caps FR, FM series .

'and about that 400v cap, does that need to be fr as well?
i had this in my cart, i know it is only rated at 160v, but it should only be getting used at ~125v'
https://www.mouser.com/ProductDetail...47-UCA2C100MPD.
Nope, do not using 160VDC cap! the dcV on the cap after the rectification is about 120VAC x 1.414 = about 170VDC!, they use 400VDC cap because that adapter is probably made to handle 230VAC as well. Never go lower Voltage than the original.

[stj]

Re: I found the bad cap, looking at replacements

for the 10uf,
i'd use rubycon LLE series 10uf 250v (on 110v mains only!!)
that range is intended for led lamps and has incredible rated lifetime!
i use them in my radio chargers.

[evilkitty]

Re: I found the bad cap, looking at replacements

sadly mouser does not carry rubycon
i ordered from digikey once but they charged me way too much in shipping, they sent be a box full of packing paper, almost entire cubic foot of it
*looks at life span *

if i use mouser i guess that limits me 1 one of these 2 with only about 1/2 the life
https://www.mouser.com/ProductDetail/647-UCY2G100MPD (400v Nichicon)
https://www.mouser.com/ProductDetail...XG201ELL100MJ1 (200v United Chemi-Con)

[sam_sam_sam]

Re: I found the bad cap, looking at replacements

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

First of all to me this a garbage power supply I would just take the low voltage power supply cord off of it and use this power supply after you replace the caps inside of it is very easy it has one screw that hold it together

Here is the link where you can buy one
One note every so often they run a sale on these power supply for $5.00 each some times they have a limit to how many you can buy and sometimes do not

http://www.goldmine-elec-products.co...?number=G20394

If you want to see the inside of this power supply look at this post at the top of the page

https://www.badcaps.net/forum/showth...t+Power+Supply

One thing that nice about this power supply is that it has an adjustment for the output voltage

The range is 4.75 to about 5.75 volts

I use this power supply for all of phones and tablet it works very good and this power supply run cool when pushing 2 amps while I am on my tablet surfing the web and charging the battery

I have pushed this power supply to 4.5 to 5.0 amps and dose get a little warm to touch

[kc8adu]

Re: I found the bad cap, looking at replacements

even fc will do on the output.
eb are fine on the input.
since i stock fc to simplify stock i use them for the startup.
they always work.
if you got hot output caps in 60sec they are backwards or rectifier leaky.
digikey offers usps 1st class and i dont mind the big flat box small orders come in.
great for shipping tcon,mains,frc,ect.
i reuse them.
agreed on that being a shit power supply.and a transformer failure may make the output live with line voltage.

[evilkitty]

Re: I found the bad cap, looking at replacements

While i do agree with that, but with how i am using the one that failed, that very nice unit is a bit large to fit in addition to being overkill
https://i.imgur.com/CyOkW3C.jpg
i have a 12v and 5v adapter in there

[sam_sam_sam]

Re: I found the bad cap, looking at replacements

Would it be easy to take a photo of the 12 volt & 5 volts power supply board I am curious of the quality of that power supply seeing the quality of the 5 volt board is to me is crap

Just a thought