Capacitor fell off

[Aranwe]

Hey folks,

 

so this is sort of awkward: a capacitor fell off my Motherboard... I had another one laying around though it's a 330 25V instead of the original 270 16V and black instead of red. My PC boots just fine after I soldered the new one, though should I be concerned ?

As you can see on the picture it's kinda ugly in that area (a bit rusty... literally!) but I think it's part of the I-gpu so no big deal ??

 

Thanks for your help

[mariushm]

The slightly higher capacitance value is not a problem. The higher voltage rating is not a problem. 

 

The  higher internal ESR of the capacitor can be a problem and could cause the circuit to be unstable or the capacitor could overheat and break down prematurely. 

The writing is too generic to figure out the manufacturer of the capacitor, so I can't determine a datasheet for that series. 

 

Ideally, you should go with a solid polymer capacitor ... not a big problem if it's with leads, you could just bend the leads a bit and solder them to the pads. Would look a bit weird/ugly but it would work much better than this current capacitor. 

 

270uF 16v or 180uF 16v polymers are very common on video cards and motherboards, so if you find some broken one you could harvest one from those and use it on your motherboard

[Aranwe]

Thank you for your advice, I'll see if I can find a capacitor on some old board. Though I'm confused, I always thought aluminium capacitors were the "nice" ones generally speaking. So why is a polymer better ? And do you think this unbranded capacitor will leak over time ?

[Beerzerker]

Just make sure when soldering you use flux on it or you could have a weak/poor solder joint.
Even if the solder roll claims to have it, use some anyway and be done with it.

I don't know why it fell off but looks to me the work done wasn't up to task for keeping it in place, like a cold solder joint.
At least no circuit traces were pulled out of the board and that's a really good thing.

[mariushm]

4 hours ago, Aranwe said:

Thank you for your advice, I'll see if I can find a capacitor on some old board. Though I'm confused, I always thought aluminium capacitors were the "nice" ones generally speaking. So why is a polymer better ? And do you think this unbranded capacitor will leak over time ?

Electrolytic capacitors are good, but the technical specifications can vary depending on the electrolyte formula used and other factors. 

For example Panasonic FC series was considered "Low ESR" more than a decade  ago or whenever it was "invented" but since then new electrolyte formulas were invented and series like Panasonic FM or FR have much lower ESR and higher current capabilities and you can barely call the FC series "Low ESR" anymore. 

Also, switching power supplies worked at lower frequencies and had more "relaxed" requirements back then, but modern power supplies actually need tighter technical parameters, much lower esr values, they work at higher switching frequencies and stress capacitors more... so a FC series capacitor is not really considered good for 

Still, the FC series continues to be manufactured and sold because not all circuits need the very lowest ESR and also, because they can be used for various purposes - for example, a lot of audiophiles prefer this FC series over capacitors with much better specifications (on paper), apparently the amplifiers sound better with them.

 

Solid polymer capacitors have the benefit that there's no liquid electrolyte inside that could degrade over time or leak and you usually get a bit lower esr compared to high end electrolytic capacitors. Of course, there are polymer capacitor series with average technical specs ... but again, different kinds for different applications. 

Because they don't have a liquid or semi-liquid electrolyte, they can be rated for much higher lifetime, as they're not that sensitive to heat and other abuse.