# Cleaning of excess soldering flux and residue from motherboard



## itsakjt (Mar 1, 2013)

Does your system have issues like slight noise coming when earphones plugged in, very occasional stutters and even less overclocking than expected? Then this thread is the right place for you.

If you examine motherboards closely especially from manufacturers like Asus, Asrock, Foxconn etc and graphics cards from Sapphire, XFX etc, you will see excess soldering flux and you will find that the PCB does not have the same texture everywhere. It will look somewhat dirty. Example? Here you go. Look inside the yellow rectangles.







Well this is an Asus Rampage IV gene 3 motherboard-High end segment.

What is flux?
Well soldering flux is a semi solid or liquid like thing which helps to reduce the melting point of the solder metal and hence prevents oxidizing of the metal while excessive heat is applied. While manufacturing it is used in plenty and some manufacturers don't care to clean it perfectly as it works "well enough" for customers(Well not me.  )

How it affects?

If you ask me, that soldering flux is a fair conductor of electricity. I have seen it in plenty of applications while trying to make a robot PCB or a speaker amplifier myself. As long as the flux was there, it was malfunctioning. Now that flux is affecting the performance of all the components and ICs installed in the motherboard. Like for example say if you receive noise from your sound card. it may have happened that the output of the card is somewhat very slightly conducted with the 12V rail of the motherboard and hence you receive the feedback.

Now to remove it.

Just remove the motherboard from the chassis because the maximum flux usually stays on the backside.

You will need- Plenty of Isopropyl alcohol, plenty of semi-lint free clothes, toothbrush and in extreme cases soap and water. Remember water never damage electronics alone. It is water + electricity that damage electronics.

Now pour Isopropyl alcohol on the backside of the board and rub the whole board with the brush and clothes. Be careful not to rip off any components if any on the back.

You will get a sticky surface and that will let you know how much excess flux was there. 

If it goes away with just alcohol then its ok. Else take some water and soap and brush the back of the board with toothbrush until it goes away. Then dry off all the water and make the back perfectly clean.

You should now get a clean powered motherboard and should be able to overclock more than before.

I tried this in all the motherboards that I owned and even of my close friends. And for the proof, see my overclock of the CPU, IMC and the RAM. 

Cheers.


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## Hood (Mar 5, 2013)

*Makes Sense*

Excellent post - that's the first time I've heard of this being a problem on motherboards, but in my experience as an auto tech, it's quite common to have strange problems caused by foreign substances on a circuit board.  When dealing with micro volts and amps it doesn't take much to alter the path or change values.  So if you are careful, this is probably a good idea, especially if you have some of the aforementioned problems.  Just be damn sure it's COMPLETELY DRY before you install it in the case!  I do have an Asus P8Z77-V that doesn't like to overclock much over 4400.  Maybe it's got a bad case of "The Flux"


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## grunt_408 (Mar 5, 2013)

My HIS 5970


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## itsakjt (Mar 5, 2013)

grunt_408 said:


> My HIS 5970
> 
> 
> http://img.techpowerup.org/130223/card698.jpg



So you can see there that in your card that much of flux near the power connector is likely to cause more noise between the +12V and ground which will affect the voltage regulation of the whole PSU and probably the whole system. Also, I bet there are other areas also like near the vga, dvi and hdmi ports having residue flux. Wipe of the PCB with a white cloth and you will see the portions of the cloth you rub with will be yellow.


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## AsRock (Mar 5, 2013)

some isopropyl with remove flux but use some thing like coffee filters as they are designed not to leave fibers behind.

Be careful not to catch on a resistor or some thing


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## Nordic (Mar 5, 2013)

I will have to take a look when I have my rig apart next week.

Edit: Did not help anything for me.


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