Friday, July 31, 2015

Desoldering capacitors from graphic card and motherboard - fix flicker screen

As explained on this blog http://howtodosteps.blogspot.com/2014/10/distorted-flickering-computer-screen.html i have a faulty motherboard and graphic card that cause the flicker on the monitor screen. This is my first attempted experience to de-solder tiny electronic component from the factory soldered circuit board. I was inspired by many videos on Youtube DIY fixing electronic component rather than buying a new one. It is well worth it because to buy a second hand motherboard and graphic cards could cost around RM100++.

However as easy as it may looks on the Youtube videos the real experience is quite unexpected and it is really tough as it requires patience, determination, and the right tools.

Tools Required to de-solder the capacitors


40 watt solder iron
De-soldering wick
Solder flux
Plier cutter
Sharp tips object




How i did it?


Safety is the number one rules so use gloves to protect my hands from accidentally touching the hot iron when soldering. Also use mouth cover to prevent from inhaling the solder flux fume. Remember the smell of the solder flux fume is very unpleasant when it burnt by the iron and it can cause headache if inhaling them too much.

First cut the protruding legs of the capacitors from the circuit board. The reason for this is to make it as flat as possible so that the solder wick can easily applied on the de-soldering area without disturbance. Although it may not be 100% flat but try to make it as flat as possible.



Secondly heat up the iron to it's desired heat - use a solder coil to test if the heat is ready. It should melt the solder coil instantly if the iron is ready for use. Once that is done - start the de-soldering process by taking the solder wick and dip into the solder flux. The reason of dipping into the solder flux so that the solder deposits from the capacitor will stick to the solder wick.



Then applied the solder wick on the capacitor legs and heat it up. Solder deposits will stick on the solder wick and doing it until the solder from the capacitors legs up completely sucked out by the solder wick.

The experience of the de-soldering process.


My first time experience of de-soldering tiny items from a circuit board is really tough. I thought it was as easy as those Youtube videos but actually not that simple. For example the wick cannot sucked out the solder because it's so small. Some people recommend to add more solder on the capacitors' leg before applying the wick but in my experience applying more solder will only delay the work. Why? this is because when the wick sucked out, it only takes the additional solder instead of the manufactured solder on the capacitor legs - so it goes back to square one which is to remove the original solder. It's a waste of time to add more solder as the manufactured solder won't blend with it.

Applying wick on the solder is not a one time process - it took me nearly 2 hours to remove 2 capacitors with frequently dipping of the solder wick inside the flux. I can still barely smell the fume of the solder flux in my head - it caused me minor headache. After many dipping and heating then the solder starting to get less.

However that is not the end - even after the solder is finished from the board the capacitors still stick strong. In the end i have to pull it off using pliers leaving some the legs still inside the hole. The unlikely solution to this is using a sharp metal object to remove it from the hole.



The End Results of the De-soldering process


After few hours of work finally i managed to get all the 4 capacitors from the motherboard and the graphic card. Thanks to the sharp metal object to push the remaining legs of the capacitors out of the hole.

What i've learned from manufactured solder is that it is tougher than the normal solder for home use. And it is extremely very fine making it difficult to catch it using the solder wick. Another thing is the hole where the capacitor legs goes through is really tiny and tightly fit. This is why it stand on the board very firm even after the solder is completely finished.

It's a tough long days but some lesson learned and thanks to the sharp tips object.

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