Electrolytic Capacitor Replacement question

I have an old Foxconn D525 mini ITX motherboard with all aluminum SMD electrolyic caps.
 
Had an issue with the motherboard and it not running for more than 3-4 minutes.
 
Looking at the board noticed one of the SMD Aluminum electrolytic caps was bulging.  First time I have seen this on an aluminum cap.


Size: 7mm X 8mm
471uF 6.3VDC
 
Purchased a bulk pack of SMD Aluminum caps but they are too small for me to install.  I have no work space on the motherboard.
 

 
Size: 6.3mm X 7.7mm
470uF 6.3VDC
 
Decided to utilize a rubycon MFG electrolytic capacitor.  It looks like a regular style small electrolytic capactor.
 

 
Size: 8mm X 11.5mm
470uF 6.3VDC
 
Will this work?

I think that given that the replacement is the same voltage and capacitance as the original then the worse that can happen is that the new cap will fail. Is the original cap also an electrolytic? If yes then it will work. What other specs do you have to consider with a capacitor, temperature?
 
I think that if RAL see this he'll be able to help.
 
Mike.

The shape and size of an electrolytic cap makes no difference as long as it physically fits in the available space.
 
Mike.

Pete if you have a very hard time handling or seeing  the small component you can solder wire leads to the mother board an inch or tow long and then solder the capacitor to those leads. Just put heat shrink tube or some other insulator on the leads.
 
Mike.

Thank you Mike.  
 
I was able to remove the old bad electrolytic capacitor fine.  It is just that I cannot guide the new smaller electrolytic capacitor pins to the holes as the capacitor is between other components.  The new SMB is about 1/2 the size of the old one.  The leads are configured to flush mount the electrolytic capacitor.   I wanted a similiar capacitor with aluminum cover.
 
I removed the little plastic base and the leads are just too short to get to the holes. Might be able to solder some leads to it though.
 
Here are pictures.  It is this capacitor that has a bulging top.  I have never seen a computer motherboard aluminum encased electrolytic cap bulge before. 
 

mikefamig said:

I think that given that the replacement is the same voltage and capacitance as the original then the worse that can happen is that the new cap will fail. Is the original cap also an electrolytic? If yes then it will work. What other specs do you have to consider with a capacitor, temperature?
 
I think that if RAL see this he'll be able to help.
 
Mike.

Click to expand...

 
Mike is right.  The Rubycon capacitor should work just fine.  The important thing is to make sure you get the polarity right.
 
With capacitors, as long as the capacitance value is the same, and the voltage rating is the same or higher, it's ok to use as a substitute.
 
A bulging electrolytic capacitor is a good sign that the capacitor is bad.

You may also want to look for an ESR and temperature ratings.
Some capacitors in switching supplies have a low ESR and 105C ratings.
 
Like the Smarthome 2413 series PLMs. Has a switching power supply. They used questionable brand capacitors. They got a reputation of failing two years and a few months over the two year warranty. There is a huge message thread on how owners replaced the capacitors in the UDI Forums.

Thank you BLH.
 
Yeah went cheap and purchased what I could find on Ebay.
 

Rubycon Radial Electrolytic Capacitor
YXG Series
470uF 6.3v 105C, Made In Japan
Size: 8mm X 11.5mm
Lead spacing: 5mm
Package of 12 pieces.
 
For $5 with free shipping.  Lots of these on Ebay.
 
The SMD capacitors are same as above with 105C temperature rating and these were 10 for $1.45 with free shipping.
 
Maximum Operating Temperature: + 105°C
Capacitance: 470uF
Voltage： 6.3VDC
Size: 6.3*7.7mm
 
Looking some more now on Ebay and see the same build as the one on the Foxconn motherboard.
 
Found another vendor which has 10 of them for $4.00 with free shipping
 

 
Geez prices are all over the place.
 
Thinking will install the Rubycon which I already ordered to make sure that that it works first.

Pete
 
I have found it easier to soldered components to the opposite side of the board when in a tight spot.
 
Mike.

Thank you Mike and RAL.
 
Yeah thought about this as it was way easier to align the tiny leads on the SMD to the traces / holes on the underside of the motherboard which I did.
 
The polarity markings on the motherboard are easy to see (see the above picture). 
 
Purchasing an SMD capacitor was the mistake here as I couldn't find like or similiar replacement caps on first look or search on Ebay.
 
I like the all aluminum capacitor as it prevents spilling of capacitor guts. 
 
I have seen a new outdoor name brand AC compressor all aluminum capactor fail (bulge) after about 3 months of running such that QC appears to be an issue.
 
Initially did have issues removing the old cap using flux, solder sucker et al.  I had to add solder then flux then used the solder sucker to clear the holes (and a tiny pin).
 
There is no real rush to repair this motherboard and it was more related to the challenge of the issue than the need of the motherboard.
 
I have done this once before and once I sent out a motherboard for repair of caps in the early 2000's

This conversation got me wondering if a ceramic or other type of capacitor could be used in place of an electrolytic? In the past I have always replaced a capacitor with the same type as the original without giving any thought to why. It was the safe thing to do.
 
So for anyone who is interested - I did a search and found this:
 
https://www.radio-electronics.com/info/data/capacitor/capacitor_types.php

Well the replacement capacitor sort of worked.  Thinking there is another one that needs to be replaced?
 
There is a maybe bulging all aluminum capacitor next to the CPU.  It is hard to tell but doesn't look flat on the top.
 
If I leave it at the BIOS information page which shows various voltages it looks good for however long I leave there.
 
The DDR2 RAM gets pretty warm.  BIOS shows a 2.0 steady VDC voltage and the RAM is 2.5 VDC.
 
If I touch the top of the new electrolytic capacitor it is really hot to the touch.
 
If I connect an SSD drive and utilize a USB to install Ubuntu 18.04 it gets about 10 minutes in to the installation and just shuts off.

I have never seen an electrolytic get hot and it couldn't hurt to replace it.
 
have seen a video where a cold liquid is sprayed over the circuit board forming frost over the components. Then power is applied to the circuit and the bad component is exposed by melting frost. The hot component becomes visible very quickly.
 
ff to 10:30 in this video
https://www.youtube.com/watch?v=b9YVgBVcADs
 
Mike.

Thank you Mike.
 
It is the new Rubycon Electrolytic Capacitor that is getting hot.  Looking at the BIOS info page none of the voltage every change.  I also remove the CPU cooler, cleaned it and used new paste on it.  That in fact dropped the CPU temperature some 10 degrees from where it was running.  (100C ==> 90C).
 
Shutting off the way it's happening would indicate some sort of heat problem.  I have turned off all of the BIOS heat shutdown stuff.  I did read that the board runs hot new.  I've never paid attention to one same board I have had running now for some 4-5 years or so.
 
Checking on the old one / info bios.  It is a Foxconn 51S (Intel Atom 510) versus this one which is a Foxconn 52S (Intel Atom 525).
 
Voltages are a tad lower on the old one but similiar and CPU is running a bit hotter.  Using a similiar Pico PSU and running Windows Server Lite (custom job). 

pete_c said:

If I touch the top of the new electrolytic capacitor it is really hot to the touch.
 

Click to expand...

How sure are you that the polarity is correct? If it is reversed, you can see excessive heating.

Of course, its possible that the reason the original died was because of overvoltage. If that is still happening, then it will fail again.