How Many Caps Should I Replace?

[sparkyrick]

My PC wouldn't POST this morning. I did some Googling and discovered this great site. I opened the case and found a bulging cap by the battery and was just wondering if I should replace every cap or just the one? It's an Elitegroup A780GM-A mobo.

[ReeceyBurger123]

Re: How Many Caps Should I Replace?

My PC wouldn't POST this morning. I did some Googling and discovered this great site. I opened the case and found a bulging cap by the battery and was just wondering if I should replace every cap or just the one? It's an Elitegroup A780GM-A mobo.

Hello what is the brand and series of the caps, seen as one has failed its probably a good idea to change them all.

[sparkyrick]

Re: How Many Caps Should I Replace?

Hello what is the brand and series of the caps, seen as one has failed its probably a good idea to change them all.

As for brand, all I can see without pulling the mobo out is OST on the cap's shrinkwrap.

[sparkyrick]

Re: How Many Caps Should I Replace?

While doing research this morning, I discovered someone posted this exact mobo on this site with the exact bulging cap.

https://www.badcaps.net/forum/showthread.php?t=17253

[stj]

Re: How Many Caps Should I Replace?

it may have been provoked, check inside your psu.

[ReeceyBurger123]

Re: How Many Caps Should I Replace?

As for brand, all I can see without pulling the mobo out is OST on the cap's shrinkwrap.

Ok well they are normally ok but can die with out any physical signs but replace that one and see if it fires up.

[Th3_uN1Qu3]

Re: How Many Caps Should I Replace?

For now, replace all four. The bulged one and its three friends that are the same as it. Make sure to use high quality capacitors from Panasonic, Rubycon or Nichicon. Harvesting them from similar locations on a dead board is okay, if you have one lying around.

[ReeceyBurger123]

Re: How Many Caps Should I Replace?

For now, replace all four. The bulged one and its three friends that are the same as it. Make sure to use high quality capacitors from Panasonic, Rubycon or Nichicon. Harvesting them from similar locations on a dead board is okay, if you have one lying around.

Agreed, use good caps with the correct esr and you should hopefully be back in business.

[sparkyrick]

Re: How Many Caps Should I Replace?

Agreed, use good caps with the correct esr and you should hopefully be back in business.

I'll get the correct ESR if ordered here, correct?

[sparkyrick]

Re: How Many Caps Should I Replace?

My B-I-L is an electronics tech at Plexus for 30+ years. He said replacing them wouldn't be a big deal and has all the good equipment at home to do it. I might just replace all of them if he is offering his services. I'm an electrician, not used to this tiny stuff, LOL!

[momaka]

Re: How Many Caps Should I Replace?

it may have been provoked, check inside your psu.

In this particular case, I doubt it.
See that coil next to those caps? That screams buck regulator right there. And if there is one thing OST caps hate, it's "high" ripple current from a buck regulator.

Looks like those OST caps are RLS series, and the bulged one is likely on the high side while the 3 others are probably all in parallel and on the low side.

Anything decent low-ESR will work here. Nichicon HM, HN, or HZ from the badcaps.net store is one excellent choice. Other choices are Panasonic FR and FM, United Chemicon KZE, Rubycon ZL, ZLH, ZLJ, and ZLG, Nichicon HD. Polymers will also more than likely work, but you might have to take some voltage measurements to see what is the highest voltage on those caps. Reason for that is because most 820uF polymers in 8mm diameter are 2.5V or 4V.

If this board is littered with those OST caps, the easiest solution would be to get appropriate Nichicon HM, HN, and HZ caps from the badcaps.net store and replace all of them, Then you won't ever have to worry.

[PeteS in CA]

Re: How Many Caps Should I Replace?

Since the PC is open and partly disassembled, if the P/S is more than 2 years old a 5 or 10 second look through the vents and fan of the P/S with a flashlight at the output caps and maybe the 5V Stby and small start-up cap could be 5 or 10 seconds very well spent.