External 5.25 enclosure PSU

[marcus905]

Hello everyone!

I used this enclosure for at least 4 years until one day its PSU went kaputt. It didn't work anymore at all, not even the led would come on, and after trying to adapt another one to the strange pinout that the plug used I opened the case to find this.

It's very similar to this one: https://www.badcaps.net/forum/showthread.php?t=7065

The fuse tripped (luckily) and the capacitors on the output side seem on their way to capacitor heaven (or hell.)

Well, let's see what we have here:

Hot input side:

1x Yalecon RX 400v 47uF CE, visually good
1x Wanlong (no series) 35v 100uF no-vent, visually good

Cold output side

3x Wanlong (no series) 16v 1000uF, 2 of which domed and bent, with bottom domed also; the other one looks OK.
1x Wanlong (no series) 25v 470uF, visually good.

I think it would be good to replace all those capacitors and the fuse, moreover I have to resolder the three wires going to the plug as while trying to adapt another similar one I had to cut those.

Which would be good replacements for those? Should I replace all of those capacitors? Other suggestions? A good way to resolder the wires?

PS: I never understood why the traces on these PSU PCBs are always covered with solder all the way unlike on motherboards and there is usually very little solder resist... any clue?

Pics attached

[TheLaw]

Re: External 5.25 enclosure PSU

http://www.sz-wanlong.com/gb2312/pro...asp?AClassID=1

This is the wanlong website. Finally found it after a while. I'm going out right now, but when I get back, I'm sure I can help you get a replacement.

[TheLaw]

Re: External 5.25 enclosure PSU

Well of course they don't have any datasheets...I doubt PCBONEZ or one of the others has archived datasheets from Shenzen Wanlong Electronics Co........

So I guess you could probably go out on a whim here....I might try Nichicon PW, Chemi-con KY, or Panasonic FC. But those are really just guesses, nothing more.

The 400V cap, I would replace anyway. Yalecon is just as bad as Wanlong. I think they are actually related.

Anyway, it would be helpful if you included diameters and maximum heights so people might be able to help you get the right parts.

[marcus905]

Re: External 5.25 enclosure PSU

These are very rough measurements as I do not have anything else but a flexible measuring tape

Yalecon is 18mm dia x 22mm height

Wanlong 35v 100uF 6.3 or 8 x 12

Wanlong 16v 1000uF 8 x 18

Wanlong 25v 470uF 8 x 15

Thanks again

[marcus905]

Re: External 5.25 enclosure PSU

Updates:

Top clearance is 23mm

I can't seem to find any 400v 47uF in the Yalecon's size, the closest is a NCC KXJ 450v 47uF 16x25 and it wouldn't fit.

Even worse for the 35v 100uF: nothing in 6.3x11.

For the 25v 470uF it's the same, the closest one is a 8x20 35v 470uF Panasonic FR that should fit

I found some Nichicons HM 8x20 to replace the 16v 1000uF that I think would fit.

Are these ok? Any suggestions for the missing sizes?

[TheLaw]

Re: External 5.25 enclosure PSU

Depending on how they are in the circuit, you can probably get away with a lower voltage cap instead of 400V+. If you are running on 120V, you can usually get away with 200-250V.

[marcus905]

Re: External 5.25 enclosure PSU

I need the adapter to travel with me so I need it working also with European voltages... what's the lowest I can safely go in that case? The cap is between the + and - right after the full-wave rectifier.

Also, why are these cRapacitors so small when compared to good Japanese ones of the same (as in label) capacitance and voltage? Are they mislabeled intentionally too?

[Colt45ws]

Re: External 5.25 enclosure PSU

How much room do you have around the cap? Also, what is the spacing between the leads?
Would something like this work?
http://www.mouser.com/ProductDetail/...RK8HVzS1oIg%3d
22x20 with 10mm lead spacing.
If it still runs, you might measure the voltages on the other caps; to see how much room you have to go down.

[marcus905]

Re: External 5.25 enclosure PSU

There is no space around the cap, and that capacitor wouldn't work as it's a snap-in and I need a standard radial lead one...

Unfortunately it doesn't run as the fuse blew, it was after I opened it that I found the domed caps and wanted to do a full recap preemptively

It seems that I will only be able to do a partial one though, replacing only the components on the cold side as those are the only ones available.

[Colt45ws]

Re: External 5.25 enclosure PSU

Whoops! I thought it was a snap in.
That works out better anyway. Heres a Radial 18x20mm

http://www.mouser.com/ProductDetail/...h0ywE3ocxbg%3d

[TheLaw]

Re: External 5.25 enclosure PSU

There is no space around the cap, and that capacitor wouldn't work as it's a snap-in and I need a standard radial lead one...

Unfortunately it doesn't run as the fuse blew, it was after I opened it that I found the domed caps and wanted to do a full recap preemptively

It seems that I will only be able to do a partial one though, replacing only the components on the cold side as those are the only ones available.

No, I believe that's a snap in. You just don't realize it. Snap in is a radial lead, just it usually has the leads pre-cut and angled so that they kind of snap through the board. Maybe you knew that.

Either way. A standard radial lead would work, but don't limit yourself to it.

[momaka]

Re: External 5.25 enclosure PSU

I need the adapter to travel with me so I need it working also with European voltages... what's the lowest I can safely go in that case? The cap is between the + and - right after the full-wave rectifier.

400V

I found some Nichicons HM 8x20 to replace the 16v 1000uF that I think would fit.
Are these ok?

Nichicon HM is usually not suitable for power supplies - ESR is too low.
These might be more suitable replacements instead:
PW, PM, HE, HD from Nichicon
LXZ, LXY, KY, KZE from United Chemicon
FC, FR, FM, from Panasonic
YXA, YXG, ZL from Rubycon

Note that the replacement caps I listed above are not all equivalent. The leftmost series are entry-level low ESR, while the series on the right are roughly just a level below Nichicon HM. Since I can't find any data sheets for your caps, it's hard to say what would be the best choice. Most likely all of them will work fine, anyways.

As for the Yalecon RX 400v 47uF cap - it doesn't need to be low ESR so don't look for a replacement from the above list. Just find something that fits and is (preferably) rated for 105C.

[mariushm]

Re: External 5.25 enclosure PSU

It looks like if you would move the leg of the fuse, you could place the 400v capacitor horizontally in that spot, maybe using bit of heat shrink tube or some other sort of insulating stuff.

And the others are probably in parallel as well, so maybe you can replace two with double capacity but only one slightly bigger, placed horizontally in there?

PS. This looks like it would fit:

http://uk.farnell.com/panasonic/eeue...5-c/dp/1539446
http://uk.farnell.com/panasonic/eeue...0mm/dp/1673495

Both 18x20 mm in size.

This would probably work as well but the ripple value is a bit on the low side: http://uk.farnell.com/nichicon/ucy2g...00v/dp/1580650

[marcus905]

Re: External 5.25 enclosure PSU

Thanks for all the replies! I didn't find the time to replace the fuse and the caps yet but as soon as I'll be able to complete the job I'm gonna post the results with pics here!

Thanks again!