[Guy Kuo]

Although I can't recommend doing this because it's easier to make things worse than better, but I just managed to reflow the soldering of a large BGA video chip package in my 12 inch dual USB iBook. The video processor chip had developed the dreaded intermittent connection to the logic board. That much was pretty easy to isolate by just pushing around on the board to find where the fault appeared and disappeared with pressure. I had hoped it was one of the surface mount components that would have been easy to resolder. Unfortunately, it turned out to be the video processor chip, a ball grid array package about 3 cm square on the underside of the logicboard below where the HD sits. Lord knows how many solder balls are in its array. Well, without any visible leads and all its connections under the chip, you'd normally be SOL and need to replace the motherboard. Since, I was out of warranty and not in the serial numbers being repaired by Apple, I had nothing to lose. I decided to attempt reflowing the video chip BGA package even though I don't have a rework station. The air flow of my heat gun wasn't too high on the low setting. High setting would blow components right off their pads.

I took my heat gun on its lowest setting and practiced reflowing some scrap circuit boards. It worked fine on small smd's and multi lead packages but I was going to be crazy enough to tackle a big BGA package. First I removed the foam like thermal transfer pad with a sharp knife. This was done in one piece so it could be reused later. Then, I masked off the logic board with several layers of aluminum foil such that only the video processor BGA and 1/2 inch of the surround PC board was exposed. The board was kept horizontal. Started with the heat gun (on low) about twelve inches away and very gradually lowered it over about ten minutes down to roughly 3 inches above the IC. The slow heat up was to reduce thermal shock on the board. Once I saw the solder on nearby SMD's change sheen, I knew I was near the right temp. The BGA is bulkier and insulates its solder balls because those are all under the package so I kept that distance for one minute to allow the solder balls to melt and reflow. Too much heat and the balls would melt and short together. Too little heat and I'd accomplish nothing. Finally, I gradually backed off the heat gun. Great care was taken to avoid bumping the board and keeping it level.

Inspection of the BGA package shows it definitely had sunk down a little closer to the logic board. That indicated the solder balls did all melt. If I was lucky I didn't short things out, popcorn the chip, or destroy the logic board. Amazingly, it worked. The intermittent video is gone and the laptop now works again. No more senstivity to pressing on the logic board.

So there you have it, an apparently successful BGA chip reflow done with VERY primitive tools. No doubt the real rework station owners will cringe at such a crude method, but heck it seems to have worked. No telling how long it will last though.

You probably shouldn't try this, but I thought it would be an interesting report.

[sniffer]

Well done. So everything is back to normal now?

[Nerozwei]

I suppose your iBook was not covered by the Logic Board Replacement programme?

[Guy Kuo]

It was outside the serial number range and the symptoms were not scrambled video but backlight faiding (unrelated to the hinge/reed switch cable). Apple wouldn't cover it under the extended repair program.

The problem was reproduced easily by very lightly pulling up on the video processor. After the solder reflow, I haven't been able to get it to fail despite pushing and prodding the board and video chip. So far so good.

[Guy Kuo]

It's still alive!

[Nerozwei]

Originally posted by Guy Kuo:
It's still alive!

Sweet

[agentz]

Cool, well done!

[Carl Norum]

Wow - you sure beat us out by a step. We just sent a couple of logic boards off with the regular work shipment, and they came back nicely reflowed. So for those of you with problems and without access to tools yourself, there are a lot of PCB manufacturers out here who might have the right heat dies and presses to help you out.

[Guy Kuo]

I'd imagine commercial reflow equipment to be quite a bit safer than the way I did it. If someone can find a PCB manufacturer willing to reflow the board, I'd definitely let them do it rather than wield a hot air gun like I did.

[Guy Kuo]

And....... it's still running!

[monkeyxiii]

Thanks for posting your experience with reflowing the graphics chip with a heat gun. I took your idea and adapted it using a standard propane torch. I just finished reflowing the graphics chip on my 12" G3 ibook with this method and it worked! The display backlight works flawlessly now.

Here is what I did:

-removed the bottom plastic case and bottom shielding
-removed the foam on top of the ATI graphics chip with a sharp blade
-opened up the display to max and propped the ibook upside down on top of a block so that the underside of the logic board is flat and the display is far from harm. This step seemed to be unnecessary since the top case never got hot enough to do any damage.
-put a few small pieces of solder on top of the chip (to indicate when the top of chip reaches solder flowing temperature)
-put a couple of pieces of solder around the chip (to indicate that the board around the chip has reached solder flowing temperature)
-lit the propane torch (benz-o-matic) and adjusted it to a low setting
-pointed torch downward and hovered the flame about an inch above the chip and constantly moved the flame back and forth across the chip to cover the entire chip area
-continued doing this until the chip slowly heated up and the solder bits I placed on the top of the chip started to melt and formed into balls
-kept the heat on the chip for about 15 seconds or so more to hopefully melt the solder on the underside of the chip (obviously the solder on the top will melt first)
-removed the heat and let cool off
-tested to see if it worked by starting up the ibook
-for me this worked the first time!

For me, the solder that I placed on the logic board beside the chip did not melt meaning the logic board beside the chip never reached the critical temperature that would cause other components to reflow or fall off. As a result, the operation was probably pretty safe. This is good because I kept all the components in the case while doing this.

I don't recommend this for everyone but if you are careful it seems to work fine.

[ghporter]

EEEKKKKKK! BGAs are BAD to mess with!!!! Of course you guys didn't have a lot to lose with computers that didn't work properly, were out of warranty, and were not covered by logic board replacement programs, but oh my!

Just the thought of a heat gun on a circuit board gives me chills. A PROPANE TORCH??? Holy COW!

[Guy Kuo]

Wow, a torch. That IS amazing. Congratulations. That's even more risk of frying the board than a heat gun. I'm amazed.

[Tuoder]

You two are crazy like a fox.

[Neato]

I too had the same problem with my iBook G3. I had previously replaced the screen hinge after dropping it which involved taking it all apart, so when the screen backlighting became intermittent, I chanced upon Guy's fix and decided to try it for myself. It was way out of warranty etc. so I had nothing to lose. Heat gun freshly bought, I made myself a rum and coke, cleared off the dining room table and set to work. I took as much of the iBook apart as I could so that nothing got in the way. I fashioned a heat baffle out of 4 layers of tin foil and laid it onto the motherboard where the BGA was, smoothin g it over so that I could trace the shape of it so that I could cut a hole roughly the same size with a scalpel. I too placed a bit of solder on top of the BGA so that I could see the melting point and fired up the heat gun at a low setting. Starting 12 inches directly above for about 10 seconds, I lowered it to about 2 inches away until the solder melted and held it there for a further 10 seconds. Then I removed the tinfoil baffle and allowed it to cool. I then attached all the bits which the iBook needed to function without fully assembling it, just so that I could confirm that it was all working fine before I went about putting it all back together for real. Presto! It was all working fine so I reassembled it, adding a touch of thermal conductive paste on the top of all 3 chips as well as their thermal pads. So there we go, it's all working again. Who knows for how long but it was better than chucking the whole thing away.

[Guy Kuo]

Nice picts and description of your technique. Mine is still working 24/7 as a server.

[MacInEnterprise]

A nice 14" iBook G3 was entrusted to me to repair. No amount of shims could get the system to boot up and stay up, but a firm thumb on the chip allowed it to boot.

Since shims were neither a desirable, permanent or clean solution, after reading the posts above, I decided to go the reflow route with a heat gun.

Now with a heat gun in hand, I'm going to reflow the solder on the ball grid array (BGA) video chip.

I've done some research on the subject leading up to this, and I've learned far more than I ever wanted or need to know. Here's what I found out:

A typical temperature profile for reworking a BGA device involves:

1. A gradual increase in temperature, of about 1 to 3 deg. a second over a period of 60 sec., up to a temperature of 150 deg.
2. Flux activation begins at 150 deg.
3. Through the flux activation phase, a slow ramp up of temp. to a peak of about 180 degs over 90 seconds.
4. Reflow begins at about 180 degs.
5. A gradual increase during the reflow phase to about 210 degs. for 60 sec.
6. Cooling phase should then begin gradually.

This doesn't mean that the ATI BGA chip on the iBook has the same temperature profile, but I think it's a safe profile to base my work on.

I think you'll see from this temperature profile, however, that it doesn't take an extreme amount of heat to reflow the solder. So careful attention to time and temperature can achieve the results you're looking for. Not paying attention to detail can result in a ruined chip. (But hey...what has anyone to really loose when the iBook is out of warranty, costs too much to replace the logic board, and is just gathering dust anyway?)

Short of a temp. gauge, I think the technique of using pieces of solder to gauge the temperature is a good one.

After the solder is reflowed, and the iBook is working again, I think some well made shims will keep it from flexing and breaking its balls again.

I'll document my work and post pictures when I perform the work...

[Dork.]

Wow. Like, wow. I bow to your mad BGA rework powers!

[Guy Kuo]

I can happily report that over two years later, that same reflowed iBook is continuing to run 24/7 as a light web server. Not too bad for such an old machine that would have otherwise gone to the dumpster.

[MacInEnterprise]

Pictures forthcoming...

I attempted to reflow the solder under the video chip over a period of 3:30 minutes, but because my heat curve was too conservative and careful, I most likely didn't get the chip hot enough, so no reliable video yet.

The iBook boots up reliably now, without having to put pressure on the chip. Unfortunately, now I don't get any video even when applying pressure to the chip.

One step forward...One step back.

To accommodate the higher heat of a repeat session, I removed the logic board entirely instead of just removing the bottom shield.

If all else fails, I may remove the BGA video chip entirely to inspect the solder balls...but considering the resistors on the other side of the board, it's the last thing I want to do at this point.

[MacInEnterprise]

Classic American mistake that has even cost NASA a Mars probe: Conversion between metric (what the rest of the world uses) and Fahrenheit (what we're too stubborn to give up).

This explains a lot about why my heating didn't begin to reflow the solder on the video chip...

Here's is a more specific and accurate curve:

1. A gradual increase in temperature, of about 1 to 3 deg. up to a temperature of 150 deg C (302 F). Pre-heating is extremely important so boards don't warp. It may take a minute or even longer to pre-heat...No need to rush it. Flux activation begins at 150 deg. C (302 F)
2. Through the flux activation phase, a slow ramp up of temp. to a peak of about 180 degs. C (356 F) over about 90 seconds. Reflow begins at about 180 degs. C (356 F)
3. A gradual increase during the reflow phase to about 210 degs. C (410 F) for 60 sec.
6. Cooling phase should then begin gradually, not abruptly.

I found a really good graph of the temperature curve here:

www.altera.com/literature/an/an081.pdf

So, as long as the heating is gradual and controlled you should be able to reflow the solder without frying the rest of the board. Yes...the whole board will get quite hot despite masking everything around the video chip. As long as it's gradual and controlled, you should be OK.

You may also smell the flux as it heats up, which is normal.

[MacInEnterprise]

Watching the temperature climb higher and higher was unnerving, but like Guy Kuo, the video chip actually did sink down by a fraction of a millimeter.

Video. Boot. You name it. One working laptop to return to my friend.

[Guy Kuo]

Originally Posted by MacInEnterprise 

Watching the temperature climb higher and higher was unnerving, but like Guy Kuo, the video chip actually did sink down by a fraction of a millimeter.

Video. Boot. You name it. One working laptop to return to my friend.

Congratulations. Welcome to the club.

[seanc]

I've just bought one of these.

I had hoped it was the screen cable but judging by the flickering and then the crash, it must be the graphics chip

I'll probably attempt this repair tomorrow and hope that I don't **** it up.

TIA for this guide.

[seanc]

Originally Posted by seanc 

I've just bought one of these.

I had hoped it was the screen cable but judging by the flickering and then the crash, it must be the graphics chip

I'll probably attempt this repair tomorrow and hope that I don't **** it up.

TIA for this guide.

Ok, I failed to get it hot enough and wussed out lol. Might try again though.

Does anyone in the UK have the facilities to do it properly e.g solder reflow oven and can do it cheap?

[kb5zhh]

A question about the loose connection: Is this likely to spill over into other video problems, or is it likely to just affect the backlight? I ask because I've found another method to fixing this problem is to just pass a constant 3.5V signal to the correct part of the display to get full brightness. If the rest of the video connections are going to stay working, then I'd rather do a repair I know I can do over this heating method.

[seanc]

Backlight problems are most often caused by the inverter cable going from the logic board to the display getting pinched and usually needs to be replaced.

[kb5zhh]

Originally Posted by seanc 

Backlight problems are most often caused by the inverter cable going from the logic board to the display getting pinched and usually needs to be replaced.

Yes, and I just opened my ibook up, replaced the inverter cable (which had no signs of damage) with a new one and still have the problem with the backlight. Additionally, pushing on the case right at the video card "helps" with the problem, in that the screen will return to full brightness while pressure is there. Thus I am reasonably certain that my problem is the loose connection that is the subject of this thread.

[seanc]

You could do the 'safe fix' like me which is to stick 3 pieces of cardboard (your mileage may vary) from the back of a notepad under the spot where the graphics chip goes. It works fine but I just want a more permanent fix.

[mistercharlie]

Hi. I just signed up here to tell you how my attempt went.
My 500Mhz G3 12" iBook started going crazy last year. Shims worked for a while, but the shims needed to be thicker and thicker, eventually the Mac would rock on the desk, the bottom was bulging so much.

So, after I came across this post, I thought I'd give it a try. After all, a laptop that works for 10 minutes at a time before the display freezes is as good as useless.

So, I pulled the bottom case off, covered everything in foil, with the screen open and hanging off the edge of the desk. I also used a couple wooden chopsticks to stop the foil blowing away (my heat gun is a borrowed paint stripping gun and puts out a fair gust of air)

I took off the thermal pad and put solder on the back of the chip, but after a while heating (gradually) the solder did nothing but change colour. No flow.

I took a piece of solder and held it up close to the gun, to see if it was getting hot enough, and it melted in a few seconds.
So I guess that the chip was conducting a lot of heat away.

I checked the height of the chip and it still seemed to be in the same place, so I gritted my teeth (no rum in the house, unfortunately!) and tried again. This time I held the gun right down, about an inch away, and held for around 10-15 secs, then backed off, removed the foil and gave it 5 minutes to cool. The chip had sunk lower.

So. Now the metal shield is back on. It booted and is running fine. I guess in an hour we'll know if it was successful. At least it's no worse than before!

Oh, and you don't even want to hear about my power cable mod. Just let me say that a phono cable is soldered directly to the dc in board, as the old socket died years ago.

I love this little iBook. So fingers crossed now :-)

[seanc]

Originally Posted by mistercharlie 

Hi. I just signed up here to tell you how my attempt went.
My 500Mhz G3 12" iBook started going crazy last year. Shims worked for a while, but the shims needed to be thicker and thicker, eventually the Mac would rock on the desk, the bottom was bulging so much.

So, after I came across this post, I thought I'd give it a try. After all, a laptop that works for 10 minutes at a time before the display freezes is as good as useless.

So, I pulled the bottom case off, covered everything in foil, with the screen open and hanging off the edge of the desk. I also used a couple wooden chopsticks to stop the foil blowing away (my heat gun is a borrowed paint stripping gun and puts out a fair gust of air)

I took off the thermal pad and put solder on the back of the chip, but after a while heating (gradually) the solder did nothing but change colour. No flow.

I took a piece of solder and held it up close to the gun, to see if it was getting hot enough, and it melted in a few seconds.
So I guess that the chip was conducting a lot of heat away.

I checked the height of the chip and it still seemed to be in the same place, so I gritted my teeth (no rum in the house, unfortunately!) and tried again. This time I held the gun right down, about an inch away, and held for around 10-15 secs, then backed off, removed the foil and gave it 5 minutes to cool. The chip had sunk lower.

So. Now the metal shield is back on. It booted and is running fine. I guess in an hour we'll know if it was successful. At least it's no worse than before!

Oh, and you don't even want to hear about my power cable mod. Just let me say that a phono cable is soldered directly to the dc in board, as the old socket died years ago.

I love this little iBook. So fingers crossed now :-)

How is your iBook now? Still working?

On the 2nd try when you did it, did the solder melt?

[agalinfl]

Anyone in Florida tried this yet? I am thinking about taking my ibook g3 14" to a local mac repair shop and show them this thread...

[altoidbox]

So far so good. I just got done reflowing my VGA chip using Guy's method. My laptop has only been running for a few minutes now, but before that the screen would screw up and the computer would lock up almost immediately after booting, and definitely if you shook the thing at all. Now it withstands light shaking and has been running long enough to come here and type this up. Doing this just saved me a couple hundred dollars I would have spent trying to get a new logic board or another old laptop.

Thanks for figuring this out, Guy. w00t!

-Joey

iBook G3 800mhz 12" of Nov 2002

[seanc]

Congratulations.

I did mine numerous times, it usually worked fine until I put the casing back on. Unfortunately I knocked my chip after I reflowed it and it doesn't work anymore, no power up . I may try reflowing again in a vain attempt to bring it back to life but I think it's dead.

[altoidbox]

Well, I guess mine's not completely fixed after all. It had the problem again this evening, though now its much more stable than before--it is at least somewhat usable now instead of dying immediately after boot. I will probably try reflowing it again if problems continue to ensue. Though my wife has been using it for a few hours now after the one incident. I'm sure it will degrade quickly with transportation.

[SafroleJay]

Xbox 360's have the same problem. I registered to say thanks for this thread. This was indispensable in fixing my xbox, especially the idea about using solder pieces to indicate correct (topside) temperature.

The gamer crowd, predictably, is populated with many young people desperate for a quick fix. They have a video on youtube. If you watch it, you'll see there is no way to know when the temperature is right, and if you simply mimic the video you'll never get it hot enough. So the procedure is widely held to be partially effective, but IMO there is too much variance in the execution of the procedure.

Here is their video: HOT AIR GUN FIX - XBOX360 - Google Video

EDIT: They changed the video link.

[mistercharlie]

Originally Posted by seanc 

How is your iBook now? Still working?

On the 2nd try when you did it, did the solder melt?

It's still going strong.
The fixes with the gun on a lower setting only held for a few hours each, so I put the gun on high heat and held it close for around 30 secs after the solder on the top melted. Up for more than 2 weeks now, including several car and plane journeys.

[willpower102]

Thanks for the stuff guys! Here's a link to the other major thread i could find out this on the net.


thinkpads.com Support Community :: View topic - t42 shuts down when i move it:

[sagefool1975]

I saw this thread and was pretty skeptical, (there are so many connections on these chips!) but I'm pretty good with the electronics and this was a good excuse to buy a heat gun. Long story short, on my second attempt I got it working (I was a little to scared of the heat my first attempt) and it continues to work after I got it completely together. Frankly I'm totally amazed. I don't think I'll be using this as a 'toss in my backpack and go' laptop at this point, but just having another machine around the apartment is a big win. Anyway thanks for the info all, it's great to bring this thing to life after 6 months of death! Woo Woo!

[dbeltramo]

This is fantastic information. I know my iBook has the same problem. Can anyone who's done this successfully recommend what type of heat gun would work best? I figure buying a heat gun is less expensive than a new motherboard.

My hardware repairs to date have been limited to replacing a hard drive or card or cable here and there, but this sounds too tempting not to try, since there's no $$$ in the budget for a pretty new Macbook at the moment.

There's a great video over at geektechnique of someone successfully doing the same repair using a tea candle holder filled with alcohol and lighting it on fire, but I think I'd rather try the heat gun route. It seems a bit less likely to burn my house down.

Alternatively, can anyone recommend a repair depot in the SF Bay area that might do this for me for a good price? Thanks for any suggestions you can provide.

- Dustin

[sysserv]

the link to their soldering stations is at

SMT, soldering irons, soldering stations, hot air blowers etc

they also have the balls for rework stuff, and they tell me that they have a new site

http://www.bgatools.co.uk

starting soon where they will be supplying balls, and all the stuff with cheap options to do a reballing where needed.

ie templates so if you move the chip, you can simply take it off, clean both sides, and cover them in flux, put the template on, pour the balls over they will go into place, stick, and then you put the chip back, and rework as normal.

i beleive the templates are still in development, but they have been available in the moblile phone trade for years, they just dont seem to supply them in the computer size chips.

any further info that anyone has on this or existing systems i would be happy as i am doing most of the research on this project.

(i have been doing bits or rework for years, and it doesnt need to be as complicated as most of the tools companies make out as seen on this link)

the man and the candles was funny, and cool, just shows, the workd isnt as difficult as they make out.

in general the feet will try and keep to the pads as long as ther is no vibration, vibration is the real big problem dong this stuff

thanks for any input that comes back to me on this i find it all extremely interesting.

regards
phil
www.sparesweb.com, laptop, notebook, spares, parts, fax, modem, ac, battery, cell pack, packard bell, nec, samsung, asus, elite, mitac,

[mistercharlie]

I just borrowed one of those Black & Decker paint stripper guns from a neighbor. I assumed this is what you all were talking about. Is there a special heat gun for this?!


Also, I saw the candle guy's fix. Pretty funny, and well done. I love these low tech hacks. Not sure if it'll kick enough heat down to keep the fix permanent, though.

[adrian1963]

Thank you everyone on this thread.

I have just completed the repair using a heat gun as suggested.

I bought a heat gun from a supermarket for 7.98 euros, and some torx drivers from a bazar for 1 euro. I used a top from a bic ballpoint pen as a tool to remove the bottom cover (after makng a bit of a mess with a screwdriver). so all done for less than 9 euros and I still have a heat gun to play with!

I followed all the instructions, put a peice of solder on top of the chip and heated it with the gun using two sheets of aluminium foil as a shield.

It's now working fine and just hope that the repair will last

thanks folks

[johau]

After my teen-age-daugther begging for one of "those fancy white laptop computers" I made my mind up and looked at Ebay what would be possible to get there. I discovered that fully functional iBooks go still for a high price, which was out of scope. But then I discovered that also a lot of iBooks marked defective are offered. After googling around I learned about the logic board repair campaign and read useful information in Mac user forums. After gathering all that information I thought I'd give it a try and finally won a defective iBook G3 700 MHz for a good price. When it arrived I already was prepared for repairing it. Then I only knew the method of putting something between the graphics chip and the bottom case, which I did and it was a success (at first). But after a few weeks the problem slowly appeared again and you only couold use the book when you'd touch it very gentle and being secure on a table, otherwise it would crash immediately. So this was not acceptable and I was looking to get a new logic board. During my reseach I found this forum thread which I read with great interest. The next day I borrowed a heat gun at my work. And today is the great day. I just did the repair and it works great! I now put the iBook together again and I am sitting on my sofa typing this post with the just repaired iBook!!
Many thanks for those who pioneered this repair method!
For security reasons I decided to go for the heat gun method rather than the propan torch. I also read this article geektechnique.org: DIY obsolete iBook logic board repair logic-board-repair with great amusement but I decided to start with a more conventional approach...

I am really happy with my "new" iBook!! - Johannes

[Guy Kuo]

I'm very pleased to read more and more people having success with the fix.

[MOLLOWITZ]

wow. i found this thread through this write up, but this seems much more doable. i posted earlier this evening asking if a 14" 1.2ghz logic board would fit a 12" model, but before i buy a new board... i'll have to try this fix. the success rate seems high.
great write up! i'll let you know how it turns out.

[seanc]

Originally Posted by MOLLOWITZ 

wow. i found this thread through this write up, but this seems much more doable. i posted earlier this evening asking if a 14" 1.2ghz logic board would fit a 12" model, but before i buy a new board... i'll have to try this fix. the success rate seems high.
great write up! i'll let you know how it turns out.

I think it would physically fit, but the battery connectors on the logic boards are different so it wouldn't work.

[MOLLOWITZ]

Originally Posted by seanc 

I think it would physically fit, but the battery connectors on the logic boards are different so it wouldn't work.

yeah, i decided not to go ahead with a replacement board. i read that you can't use the same battery anymore, either (different voltages).
I opened up my ibook today (quite a task) and was a bit intimidated using a heat gun on such a tiny, tiny area with so many parts and instead went with the temporary fix of inserting some cardboard pieces underneath the main case - above the ati chip. and viola! works great... for now. it would have also taken much more time to rework the soder, so overall i was just lazy.

[earthlings]

interesting

[earthlings]

Guy Kuo's post.

lucky. I wish I could of done that by myself, but I sent mine in a few weeks ago, and they lost everything in my laptop.

But congrats