Did you de-solder the caps before measuring them? It makes very little sense to measure them in the board. And if you de-solder them, might as well solder new ones back in, they're cheap. I say just go ahead and replace all 5.
I've recently fixed a dead mobo by repllacing 14 caps that were ever so slightly bulged at the top. It fixed the mobo, but the interesting thing was that the caps generally measured more or less OK and indicated measured capacity 1.5x their nominal value. I don't have an ESR meter, unfortunately, I bet their ESR was through the roof.

no I didn't desolder them, thats why the kind of weird question because I wasn't sure if they should all hold charge in circuit as a rule or not. I have been considering to change all 25 caps but the 5-10 minutes I give this board every few weeks just isn't enough time.

Yeah your right perhaps ill just change the 5 for the start, shouldn't take more then 15 mins

treeman wrote:

I wasn't sure if they should all hold charge in circuit as a rule or not.

The way I see it, it heavily depends on the circuitry around them, and the voltage they're charged to as certain voltage will start opening diodes and transistors in the ICs and on the board. That's why I think any in-the-board measurements have zero diagnostic value. Short of maybe measuring LF and HF ripple with a decent oscilloscope while the board is powered up.

Have a look at all tantalum caps as well while you're at it. Those tend to short out when they get old and that will often produce the same error.

yeah thanx guys, changing the 25 electrolytic caps and 7-8 tantalums that this board has was the right thing to do in my mind since it has 0 visual damage and looks very clean and yes I tested the bios in a external reader and the image looks fine.

However I could never bring myself to invest 1-2 hours for a full recap as playing the mental chess game of what if and what's next always brings me to the point that this model is just not that interesting at the moment to me, so when I am really bored I sometimes poke 5-10 minutes at it.

I guess maybye ill recap it in stages.

Check the tantaulms voltage rating vs the voltage they're being used at. If they're rated at 2x or more their working voltage, they are very reliable. Check them for a short; if they're OK, then leave them.

Lytics need to be tested with AC, not DC, and your resistance meter inserts a DC current, which is what charges the capacitors up. As has been said, to test them individually, you have to remove them (or disconnect one leg), so if they're old you may as well just replace them. If there's room, I like to use the next step up in voltage rating; the higher-voltage parts tend to have lower ESR and more thermal mass to withstand temperature extremes. Definitely use 105ºC-rated parts.