Is this a blown cap on my motherboard?
- Thread starter beelzerob
- Start date
mdesmarais
Active Member
Place the tip on top of the braid. You don't need to press on it, just let it rest there.
Feed some solder in between the braid and the iron. It should melt, and free the braid. Then take the braid out of there. ;-)
If the cap is small enough, place the iron such that it is touching both leads. Feed solder in between the iron and the leads.
When you have a nice ball of liquid solder on both pins, gently pull or pry the cap out while keeping the iron on (works best if you have the board tipped up). Very little force should be required- if you are forcing it, you will pull the barrel out of the board.
Now that the cap it out of the way, try the wick to remove the solder from the holes. I like a little vacuum bulb myself.
And yes, tips are usually pretty cheap. I'd get a new one if yours will not perform using the steps I outlined. You need to add solder to get heat transfer- the iron alone will not do it.
Feed some solder in between the braid and the iron. It should melt, and free the braid. Then take the braid out of there. ;-)
If the cap is small enough, place the iron such that it is touching both leads. Feed solder in between the iron and the leads.
When you have a nice ball of liquid solder on both pins, gently pull or pry the cap out while keeping the iron on (works best if you have the board tipped up). Very little force should be required- if you are forcing it, you will pull the barrel out of the board.
Now that the cap it out of the way, try the wick to remove the solder from the holes. I like a little vacuum bulb myself.
And yes, tips are usually pretty cheap. I'd get a new one if yours will not perform using the steps I outlined. You need to add solder to get heat transfer- the iron alone will not do it.
You will cry once you find out
It is unbelievable how many perfectly working devices have to be thrown out because of JUST a cap issue. I have probably lost 30 PC's and various other devices (both work and personal) to bad caps. I JUST lost 2 high end fax machines (identical make/model, died around the same time) to bad caps. Sometimes I wonder if the bad caps were installed on purpose, just to keep these electronics companies in business. Someone should do a study on how these bad caps have affected the environment.
beelzerob
Senior Member
Ya, but on the youtube videos I saw last night, they only used the iron!
So, to remove the solder from the cap in order to free it, I've got to add solder. *cry* No wonder I suck at this.
beelzerob
Senior Member
I've got a vacuum bulb.
So is this a good approach? I melt a blob of solder onto the iron...I then lower that onto the cap pin so the glob encompasses the pin and solder on the board. Wait, what...20 seconds? Then use the vacuum bulb to suck it all away? Or should the cap pin actually wiggle at some point if I reach under the board and try to move it?
The caps are pretty big, so I can't do both pins at the same time.
When I watch the videos, I swear, it just seems like they melt the solder with the iron, and it stays a nice flowing liquid for a second or so even after the iron is gone. For me, it always seems like the solder is hardening WHILE the iron is still touching it. This is a 30w iron.
So is this a good approach? I melt a blob of solder onto the iron...I then lower that onto the cap pin so the glob encompasses the pin and solder on the board. Wait, what...20 seconds? Then use the vacuum bulb to suck it all away? Or should the cap pin actually wiggle at some point if I reach under the board and try to move it?
The caps are pretty big, so I can't do both pins at the same time.
When I watch the videos, I swear, it just seems like they melt the solder with the iron, and it stays a nice flowing liquid for a second or so even after the iron is gone. For me, it always seems like the solder is hardening WHILE the iron is still touching it. This is a 30w iron.
mdesmarais
Active Member
If you can't do both pins at the same time, you will need to suck the solder out of at least one hole.
Touch iron to lead and board at the same time. Feed solder in to help the heat transfer- it should melt and you should see the flux bubbling off. You should be able to wiggle the lead with the tip of the iron- squeeze the bulb out, place the tip of it in the molten solder right at the base of the lead (opposite side from the iron) and release. If it doesn't get all the solder out, you'll need to re-solder and try again. You can also try dropping the opening on the bulb right over the lead, then quickly removing the iron and sucking the solder out.
If you can get one pin free (wiggles when cold) you can use my 1st technique to finish the job.
If you get most of the solder out, but the pin is still sticking, one trick you can try is to heat it up, then use a small tool to wiggle the pin while removing the iron- if most of the solder is gone, it usually will prevent it from "setting" and keep the pin free.
I haven't watched the videos, but I have ~35 years of practice. ;-)
markd
Touch iron to lead and board at the same time. Feed solder in to help the heat transfer- it should melt and you should see the flux bubbling off. You should be able to wiggle the lead with the tip of the iron- squeeze the bulb out, place the tip of it in the molten solder right at the base of the lead (opposite side from the iron) and release. If it doesn't get all the solder out, you'll need to re-solder and try again. You can also try dropping the opening on the bulb right over the lead, then quickly removing the iron and sucking the solder out.
If you can get one pin free (wiggles when cold) you can use my 1st technique to finish the job.
If you get most of the solder out, but the pin is still sticking, one trick you can try is to heat it up, then use a small tool to wiggle the pin while removing the iron- if most of the solder is gone, it usually will prevent it from "setting" and keep the pin free.
I haven't watched the videos, but I have ~35 years of practice. ;-)
markd
pete_c
Guru
I held the board in a perpendicular manner initially heating one of the terminals (sideways a bit) while push the cap to one side. Once one lead was out then I did the same with the second lead only pulling this time on the cap.
After I was done looked and one pin had taken all of the solder out of the hole and I could see light thru it. The other one didn't. I then added a bit of solder to the hole and used the solder vacumn sucker. I finally used the small saftey pin to make the hole a little bit bigger.
Put solder on the soldering iron then clean the tip ...so you can see a nice coat of solder on it with no globs. When you touch the tip of the soldering iron to the cap terminal you will see the solder melt right away...its just a few seconds...
Over the years have built small electronic kits ....but really learned to solder in the 1960's building Knight kits (ham radio code transmitter), shortwave radio and my first stereo.
My eyes are not as good anymore...so I don't solder as much as I used to...years ago used to use one of those circular flourescent lamps with a center magnifying glass. I still have it attached to my workbench but the workbench is not set up to use at this time...
After I was done looked and one pin had taken all of the solder out of the hole and I could see light thru it. The other one didn't. I then added a bit of solder to the hole and used the solder vacumn sucker. I finally used the small saftey pin to make the hole a little bit bigger.
Put solder on the soldering iron then clean the tip ...so you can see a nice coat of solder on it with no globs. When you touch the tip of the soldering iron to the cap terminal you will see the solder melt right away...its just a few seconds...
Over the years have built small electronic kits ....but really learned to solder in the 1960's building Knight kits (ham radio code transmitter), shortwave radio and my first stereo.
My eyes are not as good anymore...so I don't solder as much as I used to...years ago used to use one of those circular flourescent lamps with a center magnifying glass. I still have it attached to my workbench but the workbench is not set up to use at this time...
beelzerob
Senior Member
I've done this...I take the iron when it's nice and hot, and melt some solder onto it (it seems to melt immediately, with a stream of smoke). I then take that and wipe it off onto the moist sponge, so that the end of the soldering iron looks nice and shiny. However, if I then touch that iron to the cap terminal and hold it there for like 30 seconds...nothing happens. No soldering melting, no cap pin moving...nothing. If I managed to get the tip of the iron into the mound of solder at the base of the pin, then it seems to kind of push that solder around. But if there's one thing I don't ever seem to be able to do, it's make existing solder melt.
Hehe..I have one of those, was using it last night.
pete_c
Guru
You can also use a bit of Flux which will help you some. The guys over at the EEEPC forum suggest it for doing some HW hacks to the netbooks.
I am still waiting though on installing a BT module onto the BT module traces of my netbook until I can use my workshop lamp/magnifying glass.
I am still waiting though on installing a BT module onto the BT module traces of my netbook until I can use my workshop lamp/magnifying glass.
beelzerob
Senior Member
Well, with a whole lot of burning smell, and a lot of sucking, I managed to remove 2 caps from my destroyable motherboard. I just put a huge blob of solder on the pin, let it set for quite a while, then sucked it away. Then I used some braid. Then while the iron was on the pin, I reached around and wiggled the cap until I could see the pin moving just a bit. Then I used the iron to push the pin mostly through. Same with the other pin. then I used the braid again to get what I could, and then I just heated up where the pin was and reached around again and wriggled out 1 pin at a time.
Then I took a sewing needle and tried working it through while the iron was on it, and that got it through and I pulled it back out. I was able to easily get the old cap pins back through the hole, so I'd say that's large enough.
I guess the remaining question is...how do I know if I've destroyed this motherboard or not (I mean other than removing the caps)? Will I know what it looks like if I "remove the trace"? The area where I was working on the motherboard had sort of a "wet" look to it, and was dirty looking. did I start melting the plastic as well? Just removing the cap is only part of the battle...the other part is not also destroying the board or the place where the cap goes back in. Sooo...how do I evaluate that, so I know if I'm doing a good job or not?
Then I took a sewing needle and tried working it through while the iron was on it, and that got it through and I pulled it back out. I was able to easily get the old cap pins back through the hole, so I'd say that's large enough.
I guess the remaining question is...how do I know if I've destroyed this motherboard or not (I mean other than removing the caps)? Will I know what it looks like if I "remove the trace"? The area where I was working on the motherboard had sort of a "wet" look to it, and was dirty looking. did I start melting the plastic as well? Just removing the cap is only part of the battle...the other part is not also destroying the board or the place where the cap goes back in. Sooo...how do I evaluate that, so I know if I'm doing a good job or not?
beelzerob
Senior Member
Here's a pic of the carnage left from removing the 2 caps.
In between the pins is just a little button of solder, and it goes through to the other side. I assume that doesn't connect to anything and it's ok if it gets smeared with solder too.
The dark stuff smeared all around is probably from the sharpie I used to make the arrows so I knew which caps to remove. But otherwise, all the "messy" area is where it looks like its wet or something. its not, though, and I can clean it off by rubbing it with my finger.
In between the pins is just a little button of solder, and it goes through to the other side. I assume that doesn't connect to anything and it's ok if it gets smeared with solder too.
The dark stuff smeared all around is probably from the sharpie I used to make the arrows so I knew which caps to remove. But otherwise, all the "messy" area is where it looks like its wet or something. its not, though, and I can clean it off by rubbing it with my finger.
pete_c
Guru
Yes it looks like you heated the area a bit. Maybe a smaller tip would help. Notice the square traces (+). These most likely go to the top of the board and are isolated from the (-) side. Removing some solder from these pads will isolate them again from the ground. The in between solder that goes to the other side might go to something else.
mdesmarais
Active Member
The amount of time and effort says to me that your iron is not hot enough. . . the boards have multiple layers of copper, intended to spread the heat (which makes them hard to solder). Your board does not look especially damaged to me. . . did the legs of the cap come out with just solder on them? If you rip out the barrel you end up with a little "tube" of copper on the leg of the cap that won't have any solder on it.
The brown stuff is the flux from the solder. Try cleaning it with a little rubbing alcohol (or go all out and buy some flux remover). But before you clean the flux, use solder wick to remove as much of the solder as you can, from both sides of the board (if you have any showing on the other side).
The brown stuff is the flux from the solder. Try cleaning it with a little rubbing alcohol (or go all out and buy some flux remover). But before you clean the flux, use solder wick to remove as much of the solder as you can, from both sides of the board (if you have any showing on the other side).
123
Senior Member
Meh, spur the economy and take the PCB down to your local "We fix everything" shop. Confirm they have a desoldering station and let a technician remove all the caps in a jiffy. You can retain the right to soldering the new caps onto the motherboard.
I have an old "solder sucker" and Weller iron (circa 1977) and I've successfuilly removed components from PCBs. However, I also have the good fortune of working for a company that has a division responsible for renting and repairing video equipment. The experienced tech removed eleven caps in short order and the PCB is in A1 condition.
PS
Did the revamped motherboard work, you ask? We'll never know. The cost of eleven, low-profile caps (DigiKey, Mouser) exceeded the cost of replacing the entire motherboard (eBay).
I have an old "solder sucker" and Weller iron (circa 1977) and I've successfuilly removed components from PCBs. However, I also have the good fortune of working for a company that has a division responsible for renting and repairing video equipment. The experienced tech removed eleven caps in short order and the PCB is in A1 condition.
PS
Did the revamped motherboard work, you ask? We'll never know. The cost of eleven, low-profile caps (DigiKey, Mouser) exceeded the cost of replacing the entire motherboard (eBay).
beelzerob
Senior Member
The economy!! Why didn't I think of that??
I'll call around and see what I can find, but this is an awful small town. I've thought of posting on the classifieds for our worksite here too, but sadly, we're like 100% software, so the only solder'ers would be hobbyists like me.
Oh, I *so* do not want to buy another soldering iron. The one I have is 15W/30W selectable, and it was definitely on 30W. As I was wiggling the cap to see the pin move, I felt the top of it getting almost too hot to touch. This seems to always be my problem, spreading heat to the wrong area, and not fast enough to the right areas.
My PC froze again last night, so I shut it off. I'll turn it on one more time to backup stuff, but I'm taking that as the final warning and won't turn it back on until it's either fixed or destroyed.
Of course, I'm just *HOPING* that the freezing problem is because of the caps, and not some insidious software issue. the first time it freezes again after begin re-capped....
I'll call around and see what I can find, but this is an awful small town. I've thought of posting on the classifieds for our worksite here too, but sadly, we're like 100% software, so the only solder'ers would be hobbyists like me.
Oh, I *so* do not want to buy another soldering iron. The one I have is 15W/30W selectable, and it was definitely on 30W. As I was wiggling the cap to see the pin move, I felt the top of it getting almost too hot to touch. This seems to always be my problem, spreading heat to the wrong area, and not fast enough to the right areas.
My PC froze again last night, so I shut it off. I'll turn it on one more time to backup stuff, but I'm taking that as the final warning and won't turn it back on until it's either fixed or destroyed.
Of course, I'm just *HOPING* that the freezing problem is because of the caps, and not some insidious software issue. the first time it freezes again after begin re-capped....
