Motherboard soldering

[fshanda]

Has anyone ever soldered anything on a motherboard. Im in the middle of my second laptop repair (Compaq Presario 1200 12XL401) at the moment. I have narrowed the problem down to a bad ac power connector. Its fried and scortched the bottom of the board. The board is not dead though and will boot with the battery. If you plug in the ac cord smoke comes out of the laptop. Replacing the board is out of the question as it costs way more than just replacing the entire laptop:rolleyes: . I found and ordered a replacement connector for $19.00 that I need to solder in place after removing the fried one.

Does anyone have any tips or suggestions, im all ears or would that be eyes.

If I cant fix the board then im going to have to figure out a way to charge the battery out of the laptop so that its still somewhat functional.

I now can say that I can appreciate Dells products even more now. Taking apart the Compaq was quite a chore compared to the dell. It took me three times longer to remove the board from the Compaq. That thing had screws everywhere. The hardest part was finding where they were so I could take them out. Its going to be interisting trying to get it back together. I think im going to have screws left over when im done this one;)

[fshanda]

Heres the top:

[EvilRick]

Just use a low wattage iron, like 40watts or so.

Get some soldering wick as well, helps to get rid of the old soder. I like it better than a solder sucker.

DON'T RUSH!

G/L, I hope you get it fixed.

[fshanda]

Thanks for the tip on the iron. I have an old P.O.S. one here from the hardware store. I have no idea how many watts it is. How do you use the wick and what do you use it on. I've never used a sucker or a wick. Is it just for removing excess solder after putting on the new connector or is it for removing the old solder from the connections to make the replacement easier.

I need to read better.helps to get rid of the old soder

[fosin]

Here's a couple of instruction pages

http://www.geocities.com/ResearchTriangle/Facility/9209/howto/desolder.html

http://www.aaroncake.net/electronics/desolder.htm

When resoldering, be sure not to hold the iron onto the board's pad too long. You could damage the board and surrounding components.

[EvilRick]

You just lay the wick on the part you want to desolder. Lay the iron on top of the wick. It will "absorb" the old solder..

It looks like braided copper, I'm not sure what the acutal metal is though.

A solder sucker is just a little squeeze bulb used to suck the hot solder off. Kind of a pain to use.

If the soldering iron you have looks like a gun, it's probably going to get to hot. You might want to grap one of those pencil looking ones, like $15 @ RadioShucks.

[n7vxj]

Fshanda, Rick is right!! If you have a gun, DON"T use it!! It's way to hot, and will burn the foil traces off of the motherboard.The wick is copper braid that is chemically treated.REMEMBER, the longer you have to leave that iron on that board, the higher the risk of frying that trace!!Only enough heat to remove the old solder, and make the new stuff flow.If you don't get the new solder hot enough to flow, you end up with a cold solder joint, and that new connector will not work properly either!!!

Just an FYI, after re-reading your post.If you have smoke coming from that thing, when you plug in the A.C. cord, then more than likely, there are fried components in the power supply circuit, besides just that connector!!

[fshanda]

There is a battery charging strip that I took off of the board also. Could that have gone bad and caused the problem? It dosent look like there is any dammage to it. The battery definitely wasnt charging since it is fairly new and was in the laptop the whole time it was being used. The battery was almost completly dead the last time I powered it up. So I know it hasent been charging, at least im pretty sure. Its my sister in laws system so I only know what im told.

The burnt connection on the MB that is in the picture is the only place that I can see any sign of dammage. Looking closely at the board it looks like someone spilled something near the back of the laptop and some of the fluid went into the back. Its a little sticky with dust stuck to it. I dont believe it was spilled thru the top since it dosent appear to be any on the keyboard or other components. Just a trace in few places near the ac connector.

[n7vxj]

fshanda, without actually seeing the board, I can't really say! Keep in mind, that these things have some very fragile components in them! A lot of times these components get fried internally, and show no signs on the exterior.If liquid did in fact get in to it, and cause this problem, there is a good chance of this, since a dead short was created by that liquid!! Looking at the pics you posted, the one showing the back side of the board, there are 2 components, that I would suspect.They are 2 round objects to the center, and the right, on the top side of the burn't spot.As best as I can tell, they ceramic disk capacitors. My suggestion at this point is CAREFULLY replace the power connector.Plug in the a.c. power cord, case off, if possible, and watch for smoke.That will at least tell you if you have another bad component, that is smoking, and go from there.Hope this helps a little bit!!!!Remember, EASY ON THE HEAT, THOSE TRACES HAVE ALREADY BEEN WEAKENED BY THAT THING SHORTING OUT!!!

Looking at the pic again, those are not capacitors, but the mounting tabs for the connector.I would however suspect the component to the left of the burnt spot.It's a capacitor labeled c something.

[fshanda]

Well heres an update.

The repair didn't work. The new connector smoked out as soon as I pluged in the ac plug. Must be a short in the pcb somewhere I cant see. Oh well it was worth the effort and I learned a little bit while I was at it.

Anyone know how I can charge a laptop battery out of the laptop. I've never seen a charging connector that looked anything like the one on this battery.

I did get all of the data off of the drive and transfered it to another computer. The only useable parts im going to get out of this thing are the 15 gig hard drive, 700mhz Celeron processor and the DVD drive. I probably could sell some of the other parts and the screen on ebay.

[madfish]

ya should be able to purchase a seperate charging station just for the batt, some hold and charge two batts at once. look on HP/Compaq's site.

Edit: Sorry Ed, I had no luck searching their site, what a SOB place to try and find anything.

I know Dell has and sells a stand alone charger for their notebooks.

[BBA]

YOU HAVE COME TO THE RIGHT PLACE...
To ask a question about soldering...sorry I couldn't help you before you were unsuccessful.

I will post my tips anyway, just to help anyone else who may attempt soldering a motherboard.

About what soldering iron to use...well, a low wattage iron is the surest way to permanently kill a motherboard. A high wattage iron is the next worse thing too.


But...If you want the best iron, go buy a $300 weller adjustable.

Now lets be more realistic ( like in the $40 range ): I have had great success with the Radio Shack/Weller butane powered portable soldering iron. You can get the weller unit from Lowes here (http://www.lowes.com/lkn?action=productDetail&productId=97360-000000273-P1KC) since radio shack stopped carrying this particular iron. You need the 0.5mm tip for motherboard work.

When I modd'd the BP6 for dual P3 use, that was the only iron I could get to do as delicate work as I needed. Trust me...when you modify a motherboard to work with processors it was never designed to work with...you either figure out some tricks or you come up with junk.

The first trick: Use the finest grade eutectic solder you can find. This will be labeled 63/37 (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F005%5F006%5F001%5F000&product%5Fid=64%2D015) or 62/36/2 (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F005%5F006%5F001%5F000&product%5Fid=64%2D013)

Basically, if you use one of these two mixes of solder, you will not have a cold solder joint, because the eutectic nature of this solder has only a 1ºF region between liquid and solid...meaning as soon as it cools one degree, the joint is solid, where as the 60/40 variety has a 7-10ºF plastic phase temperature range where any slight vibration during cooldown from liquid state to solid state will leave a less than perfect coupled connection.


The iron tip will become dull and insulative after oxidation at temperature. The best part about the adjustable power gas iron is the ability to control temperature up and down quickly to any circumstance. Maintain a low enough tip temperature so that the tinning on the soldering iron tip stays shiny...if the iron temp is too high the solder will evaporate and expose the tip material to the air/oxygen where oxidation will rapidly occur. WHen this happens, the tip will turn a dull silver/brown color and will not conduct heat well.
Use this tip cleaner compound (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F005%5F006%5F001%5F000&product%5Fid=64%2D020) It will really help keep soldering iron efficiency up.


You will need a damp sponge to wipe the iron tip on frequently during soldering.

You can use solder paste to promote de-oxidation during unsoldering of components using solder braid (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F005%5F006%5F001%5F000&product%5Fid=64%2D2090). Using desoldering braid ( or wick ) is the best method of removing solder from surface mount devices/PCB mount devices ( other than a microminiature soldering station that cost $3000 and up ).


You will notice that when you first try to liquify the old motherboard solder, it will be much easier with a little rosin flux and some fresh solder application on the old solder...this is a trick that will greatly improve heat transfer/liquification of the old solder. Some times, it's the only way to remove soldered components without destroying the PCB itself.

Good luck soldering...if you have any questions, IM/e-mail me or post here.

[n7vxj]

BBA, I don't know where you went to school to learn how to solder, but please let me know so I can make sure I don't send my kids to it!!! A gas powered iron on a pc board???? And a low wattage iron will kill a board that already has has heat damage to the trace from being fried??? No, I don't think so!! Yea, you are right about one thing though, the best iron is an adjustable wattage iron, obviously he doesn't solder enough to warrant that expense! Only us ham radio operators, an electronics nuts use those.And tip cleaner?? Use it once, when you fire up the iron, tin the tip, and then use a damp sponge, and re tin the tip with fresh solder after using it, shaking off the excess solder.Yea, I have a little background in that stuff, only been in electronics since I was 15, so I guess that means, bout 30 years now. Repaired communications equipment in the military, licensed ham radio operator for 10 years now.Hummmm just a little background, I would say.

[BBA]

n7vxj...I think I will put my soldering skills against any person on the planet.

I'm sure that a lot of people will testify to that. You just haven't seen or tried what I have...which is understandable.

As for where I learned to solder? It strted when I was about 10 yr's old, my father was and still is the head professor of electronics at FCCJ here in Jax. I learned a lot from him, then in school taking electronics courses, then in the Navy, even taking microminiature soldering courses.
I was first place in every electronics competition in vocab/special olympics in my home town. My first job ever was TV/Radio/VCR and CB repair technician, started that when I was still in high school. Last but not least, I am ISCET certified in home electronics. ( did that about 20 years ago.)

Have you ever changed CPU socket pins in a motherboard? I have, and I can show you pictures of how perfectly the solder jobs came out. I modified a BP6 to work with dual P3's with no adapters way back before there was any dual P3 motherboard. ( I am the first person to get a dual FC-PGA P3 processor to work...EVER ) I have made the frontpage of almost every hardware sight for that, including hardocp, bp6.com and a lot more. Even made comment in an article at ZDnet.

All I can say is you do thing two ways, one way with equipment that cost a lot of money, and the other way with what you can afford and get hte job done. I can honestly tell you the Weller portasol is as good as a weller $300 soldering station...better in some respects even.

[fosin]

Originally posted by n7vxj
the best iron is an adjustable wattage iron, obviously he doesn't solder enough to warrant that expense! Only us ham radio operators, an electronics nuts use those.

I'm neither and use one of those. Place I used to work made motherboards and they made you take all the solder training classes. Once you get used to one of those things...
Got a gas one also. Rarely use either one anymore since I have several friends that repair electronics for a living, so...

[fshanda]

Thanks for the tips guys. I dont think my problem was a bad solder job but a fried MB. It could have been me though, I will admit. The tip about what solder to use would have come in handy when I was starring ate the rack with 20 didderent kinds at the radio shack. I just purchased a 35 watt iron that did a pretty good job.

[n7vxj]

O.K., you have soldering skills.The one thing you didn't really think about however, or a least it didn't appear to me that you did, is the fact that you recommended solder that your layman, as a rule doesn't even have access to, and second from my point of view is that with our level of experience, the weller portasol would be nothing for us to work with, but what about the guy who doesn't have the knowledge, or experience soldering that we do.He would fry that mobo, or any other delicate electronics, in a second using one.I appologize for flying off the handle like that, but when I read your response, it sounded like you didn't stop to take these things into consideration.And one other thing you forgot to tell him.If you're gonna be using liquid flux, you need to use flux remover after everything has cooled down to remove the flux build up around the joint....lol

[BBA]

np man...you don't need to apologize.

Yea...I neglected to mention using flux remover. I kind of thought about adding it in, but I didn't want to make an article out of the post, and since I did mention that I only use flux to get old solder off I figured it was ok. I did not want to say anything about using it as a prep for new solder ( since removing old solder generally tins the foil traces anyway.) Also, when people use flux remover spray, they generally end up going overboard and melting or discoloring plastic panel/controls/buttons on whatever they are trying to clean. So, it's one slightly unneeded thing if you don't go hog wild on the flux.

As for access to 63/37 or 62/36/2...it is all over the shelves at radio shack.

[n7vxj]

;) HaHaHa, I guess it's been longer than I realized, since I've been to Radio Shack!!! Last time I was there, all they had was 60/40.Guess, I'll have to stop in there soon, and see if they actually carry something I can use now!!!! lol

[Axel]

The only thing I've ever successfully repaired on a mobo is the CPU heat sink mounting frame that fractured due to a manufacturer's defect - I repaired the fracture with super glue - then cut apart an old floppy and used plastic strips from it and more super glue to re-enforce the frame some more - used that same method to repair an expensive set of KOSS headphones my 5 year-old got hold of one too many times. Both are still going strong.

As for soldering anything to a modern modo, by the time you actually purchased everything you need to do it right, and fix a board that is already obsolete ( everything on the store shelf is, by definition , by the time it gets to the shelf to be sold ) you might have saved your time and frustration and just gotten another board. As for laptops - I have 4 in the house now - all company supplied - two mine, two my wife's.... Doubt I'll ever buy a lappy with my own money - good ones are too expensive and cheap ones are too disposible... then there's the OEM issues - everything takes a special connector for every stinking model - what's the point? And chances are it's built in and requires a special driver that will only be available from the OEM for the next 2 windows OS versions...... no thanks - too frustrating.

[BBA]

As for soldering anything to a modern modo, by the time you actually purchased everything you need to do it right, and fix a board that is already obsolete ( everything on the store shelf is, by definition , by the time it gets to the shelf to be sold ) you might have saved your time and frustration and just gotten another board.

LOL...I can see ytour point of view, it's not my point of view...but I can see it. :D

As for why solder? Well, when you want custom devices, sometimes you have to make them for yourself. The truth is, learning electronics is not hard, and it has saved me large amounts of money I would have spent by otherwise buying new stuff. It also paid my bills for a few years :)

And all the people with dual processor P3's...well, they can thank me too. :D

[Axel]

custom is cool -

I make my own chainmail armor as a hobby - it started because I couldn't afford what I wanted - and later couldn't find the quality I wanted......

but - I'm not a big " climb the mt because it's there" kind of guy -

still think you'd be better off replacing than attempting repairs on a modern PCB which might have as many as four imbedded layers of foil and connections with low temp solder.

My time is worth more and my frustration tolerance isn't too high..... and most such projects turn up costing 3 times as much in materials than a straight replace - when you factor in your time, which most of us don't - it isn't anywhere near worth it.

[BBA]

I will argue against that point of view for a great number of people at BP6.com

The Abit BP6 was the original dual socket 370 motherboard, many had attempted to run dual coppermine P3's on it and failed...they said it was not possible. That is exactly why I made it work, and I was the first to do so, by directly modifying the motherboard cpu socket configuration. This eventually lead to other improvements in the BP6 such as the improved filtering by replacing voltage regulation filter capacitors with larger ones and discovering the voltage regulator IC being insufficient for the task of running stable even with a celeron on it, not to mention the P3. Changing that one vr chip was pretty easy to a skilled solderer and cost only a few dollars to do, much less than buying a new motherboard.

I also modified video cards and such, which really helped a lot of people who wanted Quadro performance out of GF1/2's, and now the big craze is modding the 128M ATI radeon 9500 into a fully fledged radeon 9700 pro...and even into a Fire GL X1. Thats a couple of big steps in saving money to get pro performance on a hobby budget.

So, whether one ends up being better off replacing than attempting repairs on a modern PCB or not lies strictly in the hands of the solderer...or in the back pocket of said solderer. :D

[Axel]

you are the great exception -

are you prepared to support the users you make mods for?

You should belong in a Development department somewhere -

but an ounce of knowledge like that here could cause more harm than good.

It's like me and my tools -

Don't ask to borrow my tools - if you need help - ask me - but I go with the tools and will end up doing some of the work.

But we aren't talking a broken drill bit here - we are talking a $100 motherboard that, if rendered useless by a less than experienced soldering type person, will render the rest of the $1000 equipment investment into so much junk until they have another working board. Tools, time and money invested - you've just spent $250 to make the rest of that $1000 machine work again.

heck - we have a hard enough time getting people to do the occasional defrag and virus definition update. you are preaching rocket science to most of the audience here, including, in part, me.

that's why you so often see me asking for motive up front. - why? - if we know why, then we can go into how with the proper warning.

[fshanda]

For a MB used in a desktop I would totaly agree. New boards are cheap. The factory replacement for this laptop motherboard was $700.00. I couldnt find a used one anywhere and am still looking for one. I put out $50.00 for tools and parts and even though I wasnt successfull I still learned from the experience. It was worth the $50.00 just for the experience of it. I had a K7S5A burn out on me, bad caps. Theres no way I would fork out a dime to try and fix that thing.

[LynninNeb]

Have an HP zt1175 laptop - a few months off the 1-year warrantee :mad: . A couple of weeks ago, the monitor began to blink sporadically. I narrowed the problem down to the AC input. Have built many desktops, but never worked on a laptop, so I was fearful of cracking it open. Took it to CompUSA repair center :bunny: . They immediately wanted to replace the motherboard - estimated $800 :mad: . Instead, I took the laptop home, figured out how to get it open, removed the necessary items (speaker cover, keyboard, fan and heatsink). I found one of the soldered pin attachments between the AC connector and motherboard was loose. Pulled out my $5.00 pencil iron and resoldered the connection. Puter has been working fine since. :D

Methinks this problem is pretty common. I don't know what I expected, but I was somewhat surprised to find the AC connector was not anchored to the case in some manner. Makes no sense to me that something so fragile and vulerable to accidental jerks on the power cord would continue to be engineered in this manner. No problem with a desktop, where the cords are not normally placed where people can trip on them, but a laptop is quite another issue.

I'm new to the forum today, so forgive me for rambling.

Lynn

[Mntsnow]

Welcome to XPC LynnInNeb :)

Me thinks they continue to do it so they can sell replacements ;)

[fshanda]

Welcome Lynn.
I wish mine would have worked out that way.
After fiddling with it for a while I came to the conclusion that the lappy had som juice of something spilled into it. I found a few places on the MB with sticky crap and fuzz stuck to it. The bad connector and other problems may have been caused by that. Of course nobody that used the system had any idea how that sticky stuff got in there.

[LynninNeb]

Thanks for the welcome guys. I do love this site!

[icemen]

Compaq and HP...what can you say, even though their products are different they still share the same idea....RIPPING US OFF!!

I'm glad that I'm not the only one to notice the poor job that HP and compaq has done. You know an engineer didn't choose to attach those tiny and delicate AC parts to a laptop motherboard. I've seen the same kind of problems posted by Lynn and fshanda.

Speaking of which.

Does anybody know where I could find that Tiny and oh so delicate ac part for a HP Pavilion zt1175?

nice message boards folks. Please don't think that i'm totally agianst HP and COMPAq...after all they can't control what happens to their products when its in a consumer hands.....what kind i say I'm clumsy and I trip over wires a lot.

[kutta78]

Hello people,
Since people are talking about soldering the motherboard of laptop, someone can definitely help me with opening procedure for laptop.
I have compaq presario 12XL125, the jack where you plug in the power adapter has gone in. I would like to open it and see if it is worth a repair.
Can some one please help me with detailed procedure?
Kutta.....a dog:D

[HaRdTiMe]

I have the same 1200-XL125... anyone wanna assist in the procedures of opening this puppy up?

[BBA]

Most laptops are similar but dismantle differently.

Some IBM's will have two little tabs alongside of the keyboard you can slide and the keyboard will lift out exposing drives and case attachemnt screws that would need to be removed to open the case.

Some newer IBM's have screws in the bottom hidden in battery/memory/drive compartments which hold the keyboard on. The keyboard will in turn cover the other screws that hold the case together.

There seems to be little reason for screw plaecement except to try and conceal them as well as possible.

In short...if no one here has taken your exact model apart, you will just have to experiment. ...AND REMEMBER...you should not have to break anything to get it apart...so if it seems like it's stuck in place...be assured that you have missed a screw somewhere!

Good Luck

[HaRdTiMe]

I have found the complete service manual for the Compaq 1200 Series online and free. If anyone is interested...

http://www.compaq.com/athome/support/msgs/1200XL101-127/index.pdf

And Ebay has power jack repacements for 11.85 shipped. Pretty cheap fix, hopefully.

[trader567]

Wow! This I gotta say is amazing. I have a problem with my laptop, an Omnibook XE2- the ac jack is busted, but I'm so excited that this problem has been experienced and discussed here in the past.

I'm going to attempt this soldering thing and I'm relying pretty much on BBA's advice as to what tools to use. I've already got my new jack, which seems the right configuration and size.

Hey BBA! I'm anxious to buy that soldering iron and the stuff you recommended, but I just had a couple of questions of my own. Firstly, what is the specific model of that Weller iron you recommended? The link you provided to Lowe's is now dead, and there's no indication of the exact model. Secondly, I did a search on iron tips to look for the .5mm for motherboard work, but the smallest I've found is 1mm. Could ya point out where to find those, buddy? Does it have to be specific to the Weller iron or are the tips generic for any iron?

You left a link to tip cleaning compound at Radioshack for the Radioshack brand. Surprisingly, that link is not dead, but it shows they don't carry it anymore, so I'd have to look for another brand that manufactures the same quality stuff. What do ya recommend?

Ok, just one more thing, if you had to give a single most important warning for what to watch out for doing this project, what would it be?

Thanks,
Steve
:bunny:

[BBA]

trader567, I dont think Lowes has the iron anymore, but it's the Weller P2 series.

This is the current series of the iron: New Weller model (http://www.newark.com/product-details/text/CD121/66372.html)

THis ones a little more expensive, Radio Shack used to sell the Tandy branded model for $29, but I havent seen that series for a while either.


I use the .5mm tip, or the 1/32" tip for PCB work.

[BBA]

This would be the same kind of tip cleaner: Link (http://www.newark.com/NewarkWebCommerce/newark/en_US/endecaSearch/partDetail.jsp?SKU=98H3029&N=4)

[BBA]

My single most important warning would be to keep the tip tinned, clean, shiny wet looking, hot enough to melt solder but not so hot it turns the tip dull.

And DO NOT apply heat for any more time than required to flow the solder to the part you are soldering.

[trader567]

hey bba- you don't understand how much comfort you give me in doing this project. even if it doesn't end up working out, i feel so much more relaxed now that you've given me advice. here's where i'm up to. i've ordered the weller iron, and it's in shipment, but i'm still working on getting the other right stuff. at radio shack for the high grade solder i've selected the following high grade solder from radio shack (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F011%5F009%5F007%5F001&product%5Fid=64%2D013) i've selected this desoldering braid (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F011%5F009%5F007%5F004&product%5Fid=64%2D2090) . i was looking at this soldering paste (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=64-022) , but they don't have it in stock, so i'll have to get it elsewhere. (if it's the right one). I still need a 1/32" tip, but i don't know if it should be the single flat tip or the double flat one. do i have the right stuff?

[BBA]

Get the 63/37 62.5/36.5/1 or 62/36/2 mixture .050" solder (stay away from the 60/40 solder, too much of a plastic phase and leads to a cold solder joint.)

The tip can be double sided, that might actually be a good thing since you will have a good chance of always getting one side clean at all times.

[Axel]

good grief - the thread that never dies...... BBA - have you bought that little item off of TV - "cold Heat" - the home soldering tool - thought of you when I first saw the commercial -

[BBA]

Nah...looks too gimicky.

[ThRoNkA]

Id rather buy it from ThinkGeek. That way they cover me if its a gimick.