Friday, April 12, 2013

Bad capacitors

The story:

One of the guys from the security company that is protecting the company that i work for asked me if he can bring me his computer because is not working and it is making some weird sounds.
After a few days he brought his computer in one bag and left it in my office...he did like this because he was in the night shift.

Powering the computer

After connecting mouse, keyboard, monitor i have pressed power button and waited for something to happen, for some sounds because the guy from the security said that after powering up the computer it's  starting to make sounds -  and i heard the speaker beeping.

After removing the side panel of the case i could see the components and notice that on the motherboard there are 4 capacitor damaged:
6,3V - 1800uF - 2 pcs
6,3V - 2200uF - 2 pcs


One more damaged capacitor is on the video card 16V - 470uF.
I have checked to see if i have some spare capacitors to replace the ones damaged but i did not have them so i went to an electronic shop to buy them. For all of them i`ve paid arround 5$.

After work i prepare my work space with everything that i will use:
soldering station
soldering pump
solder
soldering paste
small plier.

My way to remove bad capacitors is: add more solder on the joint and remove it with the soldering pump. From my experience i know that this is a good approach to this task.
If you try to replace a capacitor please take care of the values on the capacitor and polarity:
The capacitor will have a stripe on it that is the negative lead (also the foot from the capacitor were the stripe is located it will be shorter) and on the board you will find: + and - marks in a circle or the most common a circle that half filled - the negative lead.


I have replaced all the damaged capacitors (from the motherboard and from the video card) and when i did this i've recorded a video that will be available soon on my youtube channel.


The assembly was easy ;)) and the computer working again. Sorry but this part i don't have it on video because the card was full and i didn't hear the warning sound and the recording stopped.

You can watch the video on my youtube channel, here is the link: http://www.youtube.com/watch?v=WfXDLno8pdI

Thank you for your attention.

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