Why did my motherboard blow a capacitor?

[StonerNixon]

I should have asked this months ago when the problem actually happened . But yeah lol 

 

amd phenom II 

Foxcon motherboard 

inside an Orion case (that came with a 475wat power supply) 

 

 

i traded a go cart for it after I redid the go cart . It worked for a while like 2 months , but then one day after shutting it for the night it just wouldn’t turn back on . After looking closelyier i noticed that the mobo has one swollen capacitor. I haven’t even tried to screw with it since then . Just wanted to get a new mobo so this cpu could have a home . But I’m just going to replace the capacitor. I’m just curious as to why it swelled in the first place? If I replace the cap , is just going to blow again ? 

[Jumballi]

Capacitors have lifespans, it reached the end of its.
There are lots of things that reduce the life span like heat and how long it continues running.

 

In some cases you can knock it off and put some solder on it and it might continue to work. (definitely do research if this solution is good for you)

[StonerNixon]

I’m just going to get a new capacitor, this one is straight swollen and scares me lol but I’m waiting on a soldering iron and cap  

 

and Ouhkay so if this one reached the end of its life , how do I tell if the others will also die the second I get a new one on here  cause if that’s the case then I myswell replace them all right ? 

[Jumballi]

Just now, StonerNixon said:

I’m just going to get a new capacitor, this one is straight swollen and scares me lol but I’m waiting on a soldering iron and cap  

 

and Ouhkay so if this one reached the end of its life , how do I tell if the others will also die the second I get a new one on here  cause if that’s the case then I myswell replace them all right ? 

They all get varying amounts of use, and even more so get different amounts of heat and have slight varying amounts of purity. one could pop the second you turn on the system again or nothing breaks for the next 10 years because you add more fans and clean the board daily.

[StonerNixon]

Makes sense , Thank you  

[Jumballi]

Just now, StonerNixon said:

Makes sense , Thank you  

no problem, also in the future @Jumballi or quote me so I get pinged, I wouldn't have noticed you responded if I hadn't forgotten to close the tab.

[BlueChinchillaEatingDorito]

16 minutes ago, StonerNixon said:

I should have asked this months ago when the problem actually happened . But yeah lol 

 

amd phenom II 

Foxcon motherboard 

inside an Orion case (that came with a 475wat power supply) 

 

 

i traded a go cart for it after I redid the go cart . It worked for a while like 2 months , but then one day after shutting it for the night it just wouldn’t turn back on . After looking closelyier i noticed that the mobo has one swollen capacitor. I haven’t even tried to screw with it since then . Just wanted to get a new mobo so this cpu could have a home . But I’m just going to replace the capacitor. I’m just curious as to why it swelled in the first place? If I replace the cap , is just going to blow again ? 

Because foxconn historically uses cheap knockoff caps back in those days. 

[mariushm]

Capacitors are there to smooth out the input voltage and output voltage of a voltage regulator (the circuit which converts a higher voltage like 12v from your power supply, to a lower voltage like 0.7v..1.3v the processor needs)

 

If the power supply is of poor quality and its output voltage fluctuates a lot (you can measure 12v on the wires, but when you play heavy games the output voltage may fluctuate a lot between let's say 11.7v and 12.3v), the capacitors will be subjected to a higher "stress" and heat up more and degrade a bit faster than normal.

 

Electrolytic capacitors do have a liquid substance in them called electrolytic which degrades over time, but also degrades faster if the capacitors are stressed a lot. Also, if there's some electric "shocks" to them , like the power supply giving more voltage than their rated voltage for super small periods of time, then the capacitor gets a bit damaged.

The heat from the chips that form the circuit which converts the voltage also degrades the capacitors over time by small amounts of time.

 

IF one capacitor is swollen, that one is too degraded to work anymore, which means other capacitors around it probably had to take over and also do the job of that capacitor, so most likely other capacitors around it were also abused and at the point of dying. You would have to replace ALL the capacitors that are in the same location.

They will have to be special capacitors for motherboards, can't be replaced with any electrolytic capacitor from the store. They must be VERY LOW ESR type and rated for 105c

 

Example in the picture below ... power comes in from the 4 pin connector, and the capacitors on the left circled in yellow (which are rated for 16v, because it's more than 12v)  are all working in parallel to smooth out the 12v and provide a buffer of energy for the regulator circuit to the right (the chips and those coils)

IF one of those is failing, ALL the 16v rated capacitors there must be replaced, as the others will also be bad, degraded, on the verge of dying... if you just put a new capacitor, that new capacitor will do the work of the other dying ones as well, so it will be overworked and die fast (within weeks or months)

 

On the right side circled in green are capacitors on the low voltage side (the 0.7v...1.4vish for cpu) ... these are also working in parallel, to smooth out everything for cpu.  Even though the voltages are small (under 1.4v usually), here the capacitors are rated for at least 6.3v because the bigger size of the capacitors gives them some technical properties which are critical.

If one is swollen, again ALL must be replaced.

You can typically replace these capacitors (in this group) with polymer capacitors rated for 2.5v or 4v and if you go with polymer capacitors you can go a bit lower in capacitance (ex if they're 820uF 6.3v electrolytic, you can use 560uF 2.5v or 4v instead) ... if they use 1200-1500uF capacitors, you can safely use 820uF.. 1000uF polymer capacitors there)

 

And ... DO NOT just solder wire between the pins of a capacitor, you will short the power supply. Worst case scenario, leave the capacitor spot empty.

 

[Beerzerker]

Another thing about caps. Sometimes when one starts going bad it can literally blowup and kill the entire setup when it goes.

It's best to not use the affected board/system until you can get the cap replaced. I've got at least one right now that's in need of recapping for the same reason you started the thread for and I'm not messing with it until I get the caps I need and get those replaced.

 

Another thing is a cap can go bad with the board not in use and it's not uncommon to see a board with swollen caps even though it had sat in a closet for years unused as an example.

Whether it's been used or not, a swollen cap is a bad cap regardless.

[StonerNixon]

Ouhkay I understand , and the one the blew for me is circled in the green , so luckily they don’t have to be special caps , just the 12v ones . I will be replacing all of them hopefully by next week . My friend has a donor board with bent pins that I will taking the exact same caps from . Also will be using his soldering iron  so I patiently wait . Thank you guys  

[BlueChinchillaEatingDorito]

35 minutes ago, StonerNixon said:

Ouhkay I understand , and the one the blew for me is circled in the green , so luckily they don’t have to be special caps , just the 12v ones . I will be replacing all of them hopefully by next week . My friend has a donor board with bent pins that I will taking the exact same caps from . Also will be using his soldering iron  so I patiently wait . Thank you guys  

What brand are the caps from the donor board? If they're cheap knockoff caps, they're probably be on their way out as well. 

[mariushm]

46 minutes ago, StonerNixon said:

Ouhkay I understand , and the one the blew for me is circled in the green , so luckily they don’t have to be special caps , just the 12v ones

ALL the capacitors in that area are "special" , in the sense that they must be VERY LOW ESR, optimized for switching power supplies.

The ones on the "bigger voltage" side (circled in my picture with yellow) will be rated for 16v because they're smoothing out 12v from the power supply. On old motherboards, it's common to find 820uF 16v or higher electrolytic capacitors.  

You can replace them with polymer (solid) capacitors, in which case you can probably go with 270uF 16v or 330uF 16v polymer capacitors. Must be rated for 16v or higher, that's critical.

 

The row of capacitors closer to cpu socket are actually more important than the "bigger voltage" row. You absolutely MUST use VERY LOW ESR capacitors there, otherwise whatever you put there will die within weeks or months and you may experience random resets. 

Because the voltage going to the processor is very low, usually under 1.4v, as I explained in the previous message, you could polymer (solid) capacitors rated for only 2.5v or 4v instead of using very low esr electrolytic capacitors rated for 6.3v or 10v. Also, you can use lower capacitance like I said, if you use polymer (solid) capacitors.

I can go into a more detailed explanation if you're really interested.

 

Why it's important to replace all that row of capacitors if one is swollen

 

I'll try to make an analogy/comparison, hopefully it's easier to understand... think of the voltage regulator like a car engine with cylinders... in the picture below you can see the circuit divided into 5 sections ... think of it like a car engine with 5 cylinders.

On motherboards, these are called "phases" instead of cylinders.

In order to operate properly, each of these phases must have at least one input capacitor (on the left side) to act like a bucket of fuel, like a fuel pump or whatever, making sure there's energy available in case the power supply hiccups or momentarily (for nanoseconds or milliseconds) can't provide energy.

The energy goes through those chips and the inductor (that coil) and then goes into the capacitors at the end (on the right) which smooth out the voltage.

The capacitors on the right also act like balancers, like collectors for the energy coming out from each phase ... ex if one phase outputs 1.21v, the other outputs 1.19v, the third outputs 1.2v ... the capacitors even out everything to 1.205v or something like that.

So it's important that each phase has at least one capacitors, otherwise that phase would not work well.

In order for the capacitors to be able to balance all the phases, the capacitors must have some very good technical properties, that "very low esr" bit... so you can't use any kind of capacitor.

 

Why replace ... you have to understand that electrolytic capacitors don't just break like a fuse or like a lightbulb. They degrade over time.  Motherboard manufacturers even take this into account when designing these circuits and this is one of the reasons why there's more capacitors than actually needed on the output of those phases, the other being electrolytic capacitors even though they're very low esr, it's not low enough so they parallel multiple capacitors to get an even lower value.

You have to view the health of an electrolytic capacitor on a scale from 0% to 100% ... from the moment motherboard goes out the factory, the capacitors will degrade, by the time the motherboard reaches you after a few months of shipping and sitting on shelves, the quality may be at something 99.8%

As those pulses of energy go through the capacitors and they heat up and cool down, the capacitors will degrade (over time). The motherboard manufacturer will account for this and pick the values and technical properties so that the motherboard will probably function without issues even when the capacitor is at something like 75% health... and at such point that capacitor will probably still visually look perfectly fine. 

When it's swollen and potentially leaking electrolytic fluid, the capacitor was so degraded, gases formed inside the capacitor due to the electrolyte being degraded and damaged that it's nearly at its dead .. think of it as capacitor being at under 10-20% of its health.

 

IF you replace just that obviously bad capacitor, the other capacitors will still be at various degrees of "wear and tear" and the output of those phases will be of poor quality.

The controller chip that controls these phases will detect that the phase with new capacitor works much better and will use that more heavily to help increase the quality of the output ... so if you have 5 phases like in the picture, instead of each phase doing 20% of the work, the phase with the new capacitor may do 30-40% of the work and the others much less - as the design was for each phase to do 20% of the work, the new capacitor will be abused, and will degrade much faster and have a shorter life.

In the meantime, the capacitors on the other phases will continue to degrade, and those phases will produce poor quality output, and it's only so much that good capacitor can do to balance and smooth out the various voltages produced by the phases, and keep the processor happy with a smooth single voltage. If it's not keeping up, you may still see resets and issues even though now no capacitor is visually swollen.

 

So replace all capacitors that have the same role as that swollen capacitor.

 

 

 

 

 

 

 

And by the way, if you tell me the exact model of your motherboard and/or maybe take some good pictures of your motherboard, I may be able to give you some suggestions on what would be suitable to buy (if you want/can to buy capacitors from a store)