First Motherboard Fix

[BustinCaps]

So I am new to soldering and electronic components. I had some capacitors go bad on my Dell mobo and decided to take a crack at it. I was successful and the computer is working great again but I have to say it was more difficult than I imagined. Desoldering the capacitors was tough but I found clearing the holes even tougher. I tried a wick and a pump. I added some fresh solder and pulled them out using a Hakko station at 650 F. Somtimes, I felt like this was not enough heat or maybe it was the small Hakko tip it came with. I will post a pic of the tip in a moment.

I would appreciate anyone's input on how to improve on this. Specifically should I use more heat or a bigger tip or both?

[mariushm]

Re: First Motherboard Fix

The holes on motherboards are often very narrow, almost exactly the size of the capacitor leads making it hard to remove solder if it gets stuck inside holes.

Often, a simple solution to this is to gently wiggle capacitors from side to side to weaken the capacitor leads at the base of the capacitor, leaving you with just the leads in the pcb.
Then, (optionally, it helps) heat the pcb from one side with a hair dryer or heat gun to bring the temperature up and make it easier to desolder. While pcb is warm, ADD a drop of flux on the leads and a bit of 60/40 or 63/37 solder on the lead and while this solder is liquid, push the wire from the top side of the board down so that the lead will come out on the part with the traces instead. Basically do it the other way around, don't suck the solde and pull capacitor out, as you'll pull solder inside the holes.
Removing the capacitor also helps with heat dissipation, making it easier for your soldering iron to melt the solder.

If this doesn't work, you can use dental picks ... or you can find on eBay tools similar to dental picks, basically some stainless steel needles as solder won't stick to stainless steel.
If there's solder inside the hole and it's hard to remove, ADD some solder on top of the hole and while solder is hot, push the dental pick through the hole and you'll push the solder to come out the other side.

[BustinCaps]

Re: First Motherboard Fix

Here is the soldering tip I used.

[BustinCaps]

Re: First Motherboard Fix

The holes on motherboards are often very narrow, almost exactly the size of the capacitor leads making it hard to remove solder if it gets stuck inside holes.

Often, a simple solution to this is to gently wiggle capacitors from side to side to weaken the capacitor leads at the base of the capacitor, leaving you with just the leads in the pcb.
Then, (optionally, it helps) heat the pcb from one side with a hair dryer or heat gun to bring the temperature up and make it easier to desolder. While pcb is warm, ADD a drop of flux on the leads and a bit of 60/40 or 63/37 solder on the lead and while this solder is liquid, push the wire from the top side of the board down so that the lead will come out on the part with the traces instead. Basically do it the other way around, don't suck the solde and pull capacitor out, as you'll pull solder inside the holes.
Removing the capacitor also helps with heat dissipation, making it easier for your soldering iron to melt the solder.

If this doesn't work, you can use dental picks ... or you can find on eBay tools similar to dental picks, basically some stainless steel needles as solder won't stick to stainless steel.
If there's solder inside the hole and it's hard to remove, ADD some solder on top of the hole and while solder is hot, push the dental pick through the hole and you'll push the solder to come out the other side.

Thanks for some tricks of the trade. It's much appreciated. What temp do you usually use for desoldering and soldering?

[mariushm]

Re: First Motherboard Fix

Motherboards have large copper planes, thick traces, several layers ... so without additional help from something that would heating the work area, I would probably set the iron to 350-380c

But I have good soldering stations, an old original Hakko 936 and a Pace hw50 for finer work... with Chinese copies or models based on 936 you may have to set the temperature higher because the heater element is often smaller power (36w vs 50w or so) and there's poorer heat transfer between heater element and tip so the iron recovers (goes back up to configured temperature) slower between operations.
The clones/copies are also often poorly calibrated, running the iron tip at 20-40c less than configured temperature).

[newtothis]

Re: First Motherboard Fix

I drop boards on my IR rework station... Melt the solder with my iron and blow through a tiny blue straw at the hole... Seriously it clears it every time