Caps under the sink, would they benefit from contact?

[robome]

Hi,

I'm about replacing the VRM lyte caps on my board with polies.
I'm quite limited in height since 8 of 10 caps are located under the CPU heat sink (LGA 775 board from MSI) which leaves just 12mm headroom. The old caps where 10mm in height but I couldn't get caps that small here around and thus have to go with 11.5mm.

My question now is if the polies would benefit from actually touching the CPU cooler to get cooled. I don't know how warm they'll get by themselves.
In the past (board is 2.5 years old) CPU mostly ran at 35°C and only went to about 45°C under load. On the other hand the CPU itself is no power beast (Pentium E2180, i.e. low end Core2Duo) and the Seasonic S-12 has a quite stable signal. Am I right in my assumption that this means not much to do for the caps and they won't heat up themselves?
On the other hand I wonder why the lytes (OST, ESR of 0.029 mO according datasheet) have failed then in the first place (all bulged though not vented through the roof but blasted the rubber plug at the bottom) - besides the reason of being utter crap.

The replace procedure itself is no biggie, already did that successfully some time ago on another board but that hadn't cap size constraints and I used normal caps.

Thanks,
Robert

[PCBONEZ]

Re: Caps under the sink, would they benefit from contact?

My question now is if the polies would benefit from actually touching the CPU cooler to get cooled.

IMHO: No, they would overheat.
You are also blocking air from leaving the heat-sink.

0.5mm sounds inadequate for top clearance too.
[For that matter so does 2mm for lytics.]

Were it me I would use a file or similar on the underside of the heat-sink [only in the area where the caps will be] and open the clearance up at least another 1mm if not 2.
.

[PCBONEZ]

Re: Caps under the sink, would they benefit from contact?

And here I thought this was going to be about caps in a garbage disposal...

[robome]

Re: Caps under the sink, would they benefit from contact?

IMHO: No, they would overheat.
You are also blocking air from leaving the heat-sink.

0.5mm sounds inadequate for top clearance too.
[For that matter so does 2mm for lytics.]

Were it me I would use a file or similar on the underside of the heat-sink [only in the area where the caps will be] and open the clearance up at least another 1mm if not 2.
.

Thanks for your answer. That little headroom surely is a design flaw of the board and I'd have gone the long road ordering some caps of 8mm height from the other side of the globe, wouldn't that system be my only system and thus needs repair fast (I'm typing this on my cellphone browser).

So I'll try to give the caps as much space to the sink as possible - and do considder modifying the CPU heat spreader.


Regarding garbage disposal. That play with words in the title only occured to me right after sending my first post.

Thanks, Robert

[kc8adu]

Re: Caps under the sink, would they benefit from contact?

where are you?
order these
https://www.badcaps.net/store/produc...products_id=79

[kc8adu]

Re: Caps under the sink, would they benefit from contact?

the original caps might be slightly improved by contact with a garbage disposal!

And here I thought this was going to be about caps in a garbage disposal...

[TheLaw]

Re: Caps under the sink, would they benefit from contact?

And here I thought this was going to be about caps in a garbage disposal...

Same.

[Agent24]

Re: Caps under the sink, would they benefit from contact?

Yes I think those poor capacitors left all alone under the kitchen sink need some contact and affection

[kc8adu]

Re: Caps under the sink, would they benefit from contact?

so my cap stock being on old grocery store shelves out under the fluorescent lights should be happier?
and to answer the op's q no i would not put them in contact with the heatsink.if you do nothing but replace with the ones i linked above they will last well beyond the systems useful life.

Yes I think those poor capacitors left all alone under the kitchen sink need some contact and affection

[inuyasha.rules]

Re: Caps under the sink, would they benefit from contact?

And here I thought this was going to be about caps in a garbage disposal...

Yes it will help if there's contact being made! Those Hobart 5hp garbage disposals sqeal and take forever to spin up with the start capacitor not conected.