Right capacitors for old P3 mobo

[inDeBois]

Hello, I want to repair old Pentium 3 mobo(has isa port...) for some old school fun:
Advance 10B QDI Motherboard http://www.motherboard.cz/mb/qdi/Advance%2010B.htm

I can't see any bad things on caps, not leaking, not bulged. But mobo started to reboot, works unstable. So i'm thinking - caps are to blame.

i want to change:
1500uf6.3v 105°C, 7 caps, manufacturer - unknown. on side is written:
105°CFF (what FF means?)
1000uf 6.3v 105°C, 12 caps, manufacturer - licon. on side is written:
ltm
105°C(m)
vent

and some other really small, that, i think, don't need to be changed (less than 100uf)

I have no idea what values of esr or ripple have those caps. Can't find any info. And overall have no experience about esr and ripple.

At local shop there are panasonic caps(no other good ones):
panasonic fr series(EEUFR1A102L) -1000uf 10v 105c ripple: 1240 impedance: 0.041
panasonic fr series(EEUFR1A152L)-1500uf 10v 105c ripple: 560 impedance: 0.030

Are those ok? (i want to make descent repair).
If not, what caps you could recommend.
What esr and ripple values?
I will be ordering caps, if i need, from http://farnell.com/

[lti]

Re: Right capacitors for old P3 mobo

All of the Licon/Fujicon caps need to be replaced, no matter how small they are.

Can you post a picture of the unknown caps?

[momaka]

Re: Right capacitors for old P3 mobo

I have no idea what values of esr or ripple have those caps. Can't find any info. And overall have no experience about esr and ripple.

At local shop there are panasonic caps(no other good ones):
panasonic fr series(EEUFR1A102L) -1000uf 10v 105c ripple: 1240 impedance: 0.041
panasonic fr series(EEUFR1A152L)-1500uf 10v 105c ripple: 560 impedance: 0.030

Are those ok? (i want to make descent repair).

It's a Pentium 3 motherboard - relatively low frequency switching and pretty low power stuff, so those caps should be fine. You can also use Panasonic FM if you like. Other possible choices are Chemicon KZE, Nichicon HD, Nichicon HW, Nichion HM, Nichion HN, Rubycon ZL, Rubycon ZLH, Rubycon ZLG, and Rubycon ZLG.

[inDeBois]

Re: Right capacitors for old P3 mobo

@lti - photos of unknown caps





@momaka - in datasheet Panasonic FM has 4000 vorking hours, fr - 6000h - so, i think, more hours would be preferable?

[Jooo]

Re: Right capacitors for old P3 mobo

Those are Panasonic FF series. If the case size is 10 x 20, the impedance is 0.023 and ripple current 1820 mA with 2000 hours lifetime.

[inDeBois]

Re: Right capacitors for old P3 mobo

>>Those are Panasonic FF series
So those caps are pretty descent, and i don't really need to change them?
As i said, there are no visual signs of caps going bad whatsoever. So i guess i will leave Panasonic ones intact, change all Licon ones, and see how mobo behaves.


About small ones. This is question in general, not about this specific mobo(i will change all Licon caps as advised). In Badcaps.nem Repair Details is written:
>> I mark and remove all the necessary capacitors *680uF and higher* @Badcaps.net - Repair Details _/ https://www.badcaps.net/pages.php?vid=11

and lti wrote:
>>All of the Licon/Fujicon caps need to be replaced, no matter how small they are.

So how it is with those small caps? When i *don't need* to change them? Is Licon/Fujicon so bad? If those where high grade caps like panasonic, rubycon, Nichicon etc., i guess, there would be no need to change them(the same for big ones). But if caps where not worst, but let say average ones, would i still need to change small ones?

[momaka]

Re: Right capacitors for old P3 mobo

@momaka - in datasheet Panasonic FM has 4000 vorking hours, fr - 6000h - so, i think, more hours would be preferable?

Not necessarily. In some applications, it just doesn't matter.
The hours your see is not lifetime but endurance time. This is the amount of time that the caps can be stressed at maximum temperature, maximum voltage, and maximum ripple current all at once without going out of spec.

In your motherboard, though, that is very unlikely to happen unless you have the PC in the middle of the desert baking in the sun or something.

So what does the endurance rating mean?
It means, for every 10C decrease in the capacitor's temperature below its maximum temperature, the lifetime doubles. So if you have a 105C-rated capacitor that is specced for 4000 hours (like Panasonic FM, for exmaple), then the cap will last at least 8000 hours at 95C. i.e.:
105C -> 4000 hours
95C -> 8000 hours
85C -> 16000 hours (almost 2 years)
75C -> 32000 hours (roughly 3.5 years)
65C -> 64000 hours (~7 years)
55C -> 128000 hours (more than 14 years!!!)

So you can see how the endurance rating works.
In general, Pentium 3 motherboards run very cool, so your caps are unlikely to go much above 40C, if even that much.

Therefore, you don't need to worry about the endurance rating that much. As long as the caps are from a reputable manufacturer, they will likely last much longer than you'll probably have that computer for.

So those caps are pretty descent, and i don't really need to change them?

Yes, you can leave them.

So how it is with those small caps? When i *don't need* to change them? Is Licon/Fujicon so bad? If those where high grade caps like panasonic, rubycon, Nichicon etc., i guess, there would be no need to change them(the same for big ones). But if caps where not worst, but let say average ones, would i still need to change small ones?
Yesterday 01:31 PM

Some people will recommend to change only 470 uF and above, others higher, and yet some people will tell you to change everything.

Personally, I think it depends both on the motherboard and the caps.

All I can say about Licon is: I have them on a Pentium II motherboard, and it still works, so I can't say that they are the worst. But that's the only experience I have with them. I usually change anything 330 uF and above, and may change a few 220 uF and 100 uF if I think that they are important (i.e. near a linear regulator). But in general, I don't bother with anything 100 uF and smaller.

[lti]

Re: Right capacitors for old P3 mobo

I haven't seen Licon caps, but they're apparently made by Fujicon. I've only repaired one device with Fujicon caps in it. It was a set of computer speakers that were eight years old at the time, and every cap was bad. I didn't find any design flaws that would cause those caps to fail (excess heat or voltage or ripple above the rated limits), so I would expect almost any caps to last at least twice as long in that application.

[inDeBois]

Re: Right capacitors for old P3 mobo

Now i have all the info for repairs. Thank you, guys.