Blown laptop capacitor

gt88

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Oct 19, 2008
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My laptop no longer turns on. No lights, no nothing. Plus its out of warranty. Ive tested the power adapter with a multimeter and its fine. I opened up my laptop and found that a capacitor has blown.

1. Could this be the cause of the laptop not turning on?. If not, what other issues would cause it not to turn on (ruling out power supply). If the RAM/HDD is dead it should still boot correct?

2. Also the capacitor does not have any values on it. How do I find out which capacitor I need to replace it? This is a picture like the capacitor which has blown.
http://img221.imageshack.us/my.php?image=96895846ye3.jpg

Ive searched the board all over and that is the only cap I can see which has blown.

Since the laptop does not boot I want to try and repair the capacitor as I have nothing to lose.

Cheers
 
What makes you think the capacitor is blown? Ceramic surface mount capacitors are fairly durable. An electrolytic cap would be more likely to blow.

Does your multimeter have the capability to measure capacitance?
 
Thanks for the reply NoNRG.

The capacitor like the one in the picture is blown becuase its half the size it should be. There is a capacitor next to the one which blew and its double in size. Where the capacitor blew there is black markings around it, which led me to believe that it blew.

Nah my multimeter doesnt measure capacitance. But my friend's one might. How to test capacitance considering the laptop does not start?

Thanks
 
Nope havent fixed it yet. I need to find out what cap it is so that I can get a replacement. But im starting to think that ill never find out which cap value I need. I rang Acer and they couldnt help. Ive also rang up a few notebook repair shops and their fees are insane, they want $99 per hour just to look at the laptop.

I might have to get a new laptop. But I am also considereing buying a second hand mobo, but my only concern is that I dont want to pay $200+ for a mobo and then find out that the laptop still doesnt turn on after putting the new mobo in.
 
maybe find someone with the same laptop and have them take a pic?
The thing is there are other capacitors on the board that are exactly the same as the one which blew but none seem to have any values on them.

If im not mistaken with my bad eyes...isn't that a resistor?
Dont resistors have several colored bands on them? I took it down to a electrical store and the guy said its a capacitor but since it has no values he doesnt have a clue which one it is.
 
Surface mount resistors have numbers on them, no bands. I can't see the picture as ImageShack is blocked fom where I'm posting, but brown, surface mount components without marked values are often small value capacitors. Try to see if it seems to be a capacitor filtering ripple in the power line, and that there's no signal going THROUGH it (the traces should have other components in parallel with it). If it's a power filtering cap, you could try to remove it as it's there only to prevent data corruption, and might have no effect at all on the circuit. If it blew though, there might be other problems around.
 
Those are regular SMD resistors, which come in different sizes. I can see no physical damage on this picture.
 
OK, I just saw the picture, the capacitor is OK, it's a ceramic or tantalum. These don't blow or leak brown stuff like electrolytics would do.

What about your battery, is it still charged, empty, etc. Some laptops don't work at all without a battery installed.

Some things you could check :
Corrosion on laptop's power adapter jack or battery contacts.
Cold solder joints on the power jack.

Check for bulged electrolytics (They look like metal cans in surface mount)
 
"This is a picture LIKE the capacitor which has blown. "

leads me to believe thats not the pic of the blown one, but one to show what it should look like.
 
Like mnewxcv said the picture is just to show you guys what the one on the mobo which blew looks like. My camera is crap so when I took a photo the quality was poor.

In regards to the battery it was full the last time we used the laptop before it stopped turning on.

Ive searched the board several times and I cannot seee anything else that is damaged. The power jack is fine.

In that picture what exaclty is that component? DragonMaster is saying its a capacitor whereas Elledan is saying its a SMD resistor. I want to know what it is so that I can get a replacement and try to change it.


Thanks guys
 
There are four components in parallel between the two planes. I doubt a resistor would be found there, especially since planes are used for power only. It should be a ceramic capacitor, which are usually brown and without markings in SMD devices. It's quite common to find multiple capacitors in parallel in a circuit (ie. 10µF, 100nF, 1000pF) to filter ripples (larger caps don't respond to transients as fast as smaller ones).

That's what SMD resistors usually look like :http://www.koaproducts.com/english/catalogue/rk73b.htm

The blown cap could be shorting between the rails, and preventing the laptop from powering up, if it's found between power planes. I'd say just remove it. Removing a cap can't do any harm. Try this first, then, if the computer works, check if it's stable, if not, salvage one from old cards.
 
It is definitely a capacitor. Try what DragonMaster suggested (removing the cap). You will need a soldering iron and maybe some solder wick. Tweezers would make the job a lot easier as well. Theres tutorial videos on YouTube showing how to remove surface mount components. Might want to check those out. The soldering iron I've used for work like that is actually a tweezer soldering iron :)

Without an impedance bridge (measures capacitance), I'm not sure how you can find the capacitance off the top of my head. If I get some time (not likely until Friday) I'll try to think of a way. If you mail me the cap, I have access to an impedance bridge... last resort maybe? Hah.

Edit: Actually, just thinking about it for a few mins. You would need an oscilloscope or something to find the capacitance without something to automatically measure it. Was thinking of maybe applying a voltage, and then calculating capacitance, but capacitors are logarithmic in nature so that wont work unless a voltage sweep is done. Anyways, back to studying, hah.
 
Without an impedance bridge (measures capacitance), I'm not sure how you can find the capacitance off the top of my head.
If the cap is blown, good luck ;-)

The only worth testing would be to check if the capacitor shorts the circuit.
 
If the cap is blown, good luck ;-)

The only worth testing would be to check if the capacitor shorts the circuit.

Yea, true. He can check that with his multimeter, right? Put the multimeter across the blown cap, and if theres no voltage across it, then its shorted.
 
Brown SMD components like that are capacitors.
Black SMD components are resistors.

Usually.

OP: Can't you post a pic of the actual damage?
 
Just an update. I got a friend to remove the cap but still no luck. I ended up buying a mobo from ebay. And with my luck when I opened the package a cap fell out. How ironic? I spoke to the seller and he told me to try and see if it works as he said in an email "those capacitors are not that important" - doubt it lol. He offered to exchange it but said to try it first. And if I was to send it back I would have to pay postage and the mobo box is big so its gonna cost me around $20, probably more.

The capacitor value is 470 EFC. 7N5

Here is a blurry picture of the size of the cap......


Anyone have an idea what that cap is? If it helps it was located right near the cpu slot.
Even if it does work I dont want a mobo that could get damaged down the track....again.

Thanks
 
I hate to say it man, but you should start looking at a new laptop. For one, I am pretty sure you board is multilayer, which means you will most like screw it up more if you are the average joe at electronic components. Also, it is very unlikely you are going to be able to really test the cap while it is in the circuit. That cap could be used as a filter, osi, phase shifter, etc... You could be looking at a short which could be caused by another component, or an open... a fully charged cap or an open cap. You can not test it unless it is by itself. Good luck on the fix though.
 
Just an update. I got a friend to remove the cap but still no luck. I ended up buying a mobo from ebay. And with my luck when I opened the package a cap fell out. How ironic? I spoke to the seller and he told me to try and see if it works as he said in an email "those capacitors are not that important" - doubt it lol. He offered to exchange it but said to try it first. And if I was to send it back I would have to pay postage and the mobo box is big so its gonna cost me around $20, probably more.

The capacitor value is 470 EFC. 7N5

Here is a blurry picture of the size of the cap......
http://img204.imageshack.us/img204/8816/image358ey8.th.jpg

Anyone have an idea what that cap is? If it helps it was located right near the cpu slot.
Even if it does work I dont want a mobo that could get damaged down the track....again.

Thanks

Looks like a solid, surface-mounted capacitor to me. Shouldn't be hard to find. Actually soldering it onto the PCB will be harder. The question remains why this cap fell off, though, as this really isn't supposed to happen. Did you look for more physical damage yet?
 
The mobo is brand new, no damage beside the cap. I might return it, even though its going to cost me to post it, I have a feeling that it will stop working down the track once the warranty is expired.
 
Yeah, returning it is probably the safest option. Of course, if you get another bad mainboard back, definitely give some negative feedback ;)
 
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