Capacitor Removal

This is a picture of my motherboard. (In my recently acquired laptop.)

Key:
Green = Power connector (jack)
Blue = caps that seem to be good
Red = cap that has 0.2ohms of resistance across it.


I do not have a DVOM that tests caps, so I am just taking measurements and guessing here. But, when I take resistance measurements from all four of those caps, the blue ones keep giving me shifting readings, which seems right becuase I know that a cap charges and whatnot, and I figured that it would hold the charge from the DVOM and then throw it back out, giving me a fluctuating reading. I was told that one of these caps go bad, and I dont know which, so thats why im taking these masurements. But, the one in red has almost NO resistance across its leads!

Now, I was wondering, if you can tell, what would happen if I were to remove this cap? would the other cap be suffecient enough to take small spikes in power from the power supply? I think it would, and the fact that there are 900 million more caps on this motherboard, I dont think it would matter at all if it had a little more noise comming in through the PSU.

I know it seems to work like this..

The two smaller caps (going in this | direction) seem to be connected to the end leads of the other two caps going in - that direction. so if I were to remove the offending cap, would it give me any problems? from what I can see, it shouldnt, right?

(Copied from my thread on www.turbobricks.com)

I was told one of these caps would be the reason my compy WILL NOT boot up. Help plz!

usually if there is a problem with a componet it reads 0 ohms (short) or infinity ohms (open)... if you suspect the cap is at fault you could remove the cap and then measure the resistance because you are actually also measureing the resistance of many many other components in the board and thus that is not a true reading you are getting...

other than shorts and opens... resistance is a bad way to tell if a cap is working or not... usually the voltage of a cap can tell you a bit more about what is going on...

(this process below probbably isn't needed because the caps probbably only deal with DC and you can use a volt meter for them then)

if you really want to diagnose the cap you will need an oscilloscope. with the 3 probes from the oscope.. Put the ground probe of the oscope to ground (the chassis works best) and the CH1 lead on the annode of the cap and the CH 2 lead on the cathode of the cap and then if your oscope is cool there will be a CH2 - CH 1 function which will subtract ch2 from ch1 and display the resultant waveform that is going through the cap. also with the oscope you can obtain the frequency and then use the formula at the bottom of my post to figure out just how much resistance the cap is supposed to have...



I woulden't take the cap out ans just see what happens because...capacators do more that just smooth out spikes in current. they have another vital role in electronics... capacators block DC and allow AC to pass through. the faster the frequency the less resistance the capacator has... This is effective at creating band pass filters which allow only ceartian frequencies to pass... also another thing that capacators do is cause a phaze shift in the waveform of the frequency... so in essence if you where to remove a single cap from your mobo (and turn your mobo on) you could be allowing DC to go where it's not supposed to, you could change some frequencies on the board, or you could cause the frequency of the circuit to be off beat with the rest of the computer causing data collisions and power spikes and power drops, not to mention that removing the cap will put a break in the circuit which will cause everything in series with that cap to cease to function...


OR you can get extremely lucky and the comp is not effected in any way.

I would replace the cap with another cap that is rated as the same value and see what difference it causes in the circuit instead of just removing it...
the formula to figure out how much resistance a capacator has...

xc(resistance)=1/2*pi*(frequency)*(capacatance)
you can't really use this because you don't have the frequency but it's nice to know...

you might have had better luck in the voltmodder's section but since I have a little background I said what the hey...

well, I removed it last night, and made my computer not function at all, so I resoldered it back on, and it still does the same thing...im starting to wonder if thats really what is bad...and if that really is a cap.