Laptop wine spill - motherboard repair

[Lomax]

My neighbour brought me his dead laptop today (a Lenovo G50-30), which I had offered to see if I can fix. He said he had spilled a small amount of wine on the touchpad a couple of weeks ago, and that a few days later it would no longer turn on. I feared it would be completely destroyed by the acidity of the wine, but after removing and examining the motherboard under a microscope I could only find two areas where there was damage, which is indeed right below the touchpad. It looks quite fixable, but some SMD components will need to be replaced as some terminals have been completely etched away, and it's possible there may damage to the one of the traces. Unfortunately, none of the components have any marking of any kind, apart from a BAT54C double Schottky diode in an SOT-23 package (in "area A" below, marked as L43₂), so I'm not sure what parts I need to get! There are what appears to be three capacitors (in "area B" below), and two of these look like they're used for decoupling, and the fifth and final part is probably a resistor ("area A"). The fact that they've been etched by the wine certainly doesn't help with the identification! I'd be very grateful if more experienced eyes than mine could take a quick look at the photos below, and let me know what you think I'm dealing with here...

[Ian.M]

You are FUBARed without either a schematic or an identical board as apart from the passive component ID problem, you've got no idea where the via in the track with the silkscreened 'J5' on top of it goes to and it looks fairly b-ggered.

[Mechatrommer]

people are happy to consume copper etchant these days.... and yet preach about safety issue if they expect to see more problems are solved, they should consume more... [sarcasm off]

[jh15]

FYI for new players to wine spills:

next to me at our kitchen bar, my wife spilled a whole glass into her Gateway laptop. I immediately unpluged and pulled the battery out.

I poured a bottle of distilled water on it after shaking it out upside down.  Then I used a a lab squirt bottle on it.

Then I started the GE oven with a thermocouple on it for 150 degrees, but calibrated the oven down to about 130 and left it for hours.

still works a charm (at least on PCLinuxos) and I later opened it to replace thermal paste and found no wine problems.  Some laptops are ressistant to spills I've heard during tests. A $600.00 unit bought years ago.

[Rasz]

https://www.elvikom.pl/schemat-lenovo-ideapad-g40-30-g50-30-compal-aclu9-aclu0-nm-a311-t39708.html?lang=en

[Lomax]

https://www.elvikom.pl/schemat-lenovo-ideapad-g40-30-g50-30-compal-aclu9-aclu0-nm-a311-t39708.html?lang=en

Great Scott! I could build my own laptop from scratch with those schematics! If you give me a couple thousand years. Joking aside, if I can figure out how to register on that forum they will be very useful indeed - many thanks!

[Lomax]

https://www.elvikom.pl/schemat-lenovo-ideapad-g40-30-g50-30-compal-aclu9-aclu0-nm-a311-t39708.html?lang=en

Ok, I've registered, but:

You have not enough of Points to download this attachment!

[Rasz]

https://www.elvikom.pl/schemat-lenovo-ideapad-g40-30-g50-30-compal-aclu9-aclu0-nm-a311-t39708.html?lang=en

Ok, I've registered, but:

You have not enough of Points to download this attachment!

you can donate five bucks or something

[Lomax]

you can donate five bucks or something

Erm, ok. So let me get this straight: these guys offer pirated copies of proprietary schematics - and they want me to pay for access!? That's... a little... greedy? 

[Ian.M]

you can donate five bucks or something

Erm, ok. So let me get this straight: these guys offer pirated copies of proprietary schematics - and they want me to pay for access!? That's... a little... greedy? 

How so?   They've got server costs, and may have had to pay full price for some of their schematics.   TANSTAAFL- you've got to bring *something* to the table, and if you don't have data they want you can share, it comes down to money or goods.  I bet you've already spent more than $5 worth of your time working on it . . . . .

Obviously I'm ignoring copyright law here - which I wouldn't be if the OEM supported 'Right to Repair' and sold full schematics at a fair market price to the general public.

[Rasz]

you can donate five bucks or something

Erm, ok. So let me get this straight: these guys offer pirated copies of proprietary schematics - and they want me to pay for access!? That's... a little... greedy? 

elvikom.pl isnt some random chinese/russian pay $20 for one pdf outfit.
"these guys" run one of the better laptop repair forums where you can get good advice even when you are in top 1% of component level repair specialists in the world. You can either contribute by helping others with problems, uploading diagrams they dont have yet, or with your mums CC#.

quoting Louis might sound cool in your head, but in real world you will pay or go pound sand.

edit: simpler option is to find broken laptop on craiglist/ebay and swap components

http://www.ebay.com/itm/Lenovo-G40-30-80FY-BAD-Motherboard-As-Is-384-62-/291613065658

[Lomax]

elvikom.pl isnt some random chinese/russian pay $20 for one pdf outfit.
"these guys" run one of the better laptop repair forums where you can get good advice even when you are in top 1% of component level repair specialists in the world. You can either contribute by helping others with problems, uploading diagrams they dont have yet, or with your mums CC#.

Ok, fair enough. Maybe I overreacted. It just looked bad enough to send my scamometer peaking Far too many people on the Internet try to make a quick buck off other people's hard work. I support "share alike" as a general principle, and find the idea of charging money for access to information that has been obtained for free - legally or otherwise - morally bankrupt. I would be happy to discuss this further, if anyone fancies having a go.

quoting Louis might sound cool in your head, but in real world you will pay or go pound sand.

I have no idea what this is referring to. No really. Louis who?

edit: simpler option is to find broken laptop on craiglist/ebay and swap components

Not a bad suggestion. Still a somewhat cumbersome way of finding the value of three capacitors.

Fee I'm charging to fix my neighbour's laptop: £0. Maybe some think that's being stupid - personally I'd like to think it's being nice.

[crispy_tofu]

quoting Louis might sound cool in your head, but in real world you will pay or go pound sand.

I have no idea what this is referring to. No really. Louis who?

Louis Rossmann. 

[Lomax]

Louis Rossmann. 

I'm probably showing my age now, but who? 

Edit: Ok, found him (on YT). Still no idea. Some dude who repairs laptops? Controversial figure, perhaps?

Edit: Ok, he seems a tad... opinionated. Nothing wrong with that. And hey - he uses Xfce; can't be all bad.

[Ian.M]

He definitely speaks his mind without fear or favour.  However he makes a living doing laptop repair in one of the pushiest high rent cities on the planet, including tackling water damaged boards that have been rejected by other repairers that have grabbed the low-hanging fruit so he certainly has the skills and business experience to back up his attitude.

You may find his "The tools I use and why I bought them" video interesting.

[Rasz]

Ok, fair enough. Maybe I overreacted. It just looked bad enough to send my scamometer peaking Far too many people on the Internet try to make a quick buck off other people's hard work. I support "share alike" as a general principle, and find the idea of charging money for access to information that has been obtained for free - legally or otherwise - morally bankrupt. I would be happy to discuss this further, if anyone fancies having a go.

I get it, I used to have this hippie attitude a lot, more at the bottom*
first two items in my link are huge hi res pictures taken by one of the forum members, exactly for the purpose of looking up component positions, symbols and tracks in case they are missing, didnt come from the sky or chinese server, someone spend time making those.

I have no idea what this is referring to. No really. Louis who?

https://youtu.be/cvzhMYp8R1g?t=18m15s
and few previous rants, your post sounded like one of those word for word

edit: simpler option is to find broken laptop on craiglist/ebay and swap components

Not a bad suggestion. Still a somewhat cumbersome way of finding the value of three capacitors.

from the picture it looks like its not just 'three capacitors', and even if it was just one track fixable by $0.00001 worth of wire its not about that wire, but a knowledge where to put it. obviously im not telling you to buy second motherboard to recycle 3 capacitors

Fee I'm charging to fix my neighbour's laptop: £0. Maybe some think that's being stupid - personally I'd like to think it's being nice.

no, this is stupid and demeaning. Its a shitty bottom of the barrel supermarket laptop to begin with (worth about $100 fully working), fixing it for free reinforces your lack of self respect. Who is your neighbour? dentist? ask for free implant. doctor? ask for free surgery. car mechanic? ask for free engine rebuild. Want to be nice? offer them help selecting decent (not lenovo) replacement, or an older hand me down.

*  just because you are trying to fix a cheap piece of shit doesnt mean its going to be free, or cheap. You can spend couple of hours reverse engineering circuit from the pcb and rebuilding it on a hunch if you like, if it was 'three capacitors' like you said you would already soldered something in their place and call it a day As it is you didnt even bother to measure voltage rails and diagnose basics like what state is the laptop when it doesnt boot.

[Brumby]

Fee I'm charging to fix my neighbour's laptop: £0. Maybe some think that's being stupid - personally I'd like to think it's being nice.

no, this is stupid and demeaning. Its a shitty bottom of the barrel supermarket laptop to begin with (worth about $100 fully working), fixing it for free reinforces your lack of self respect. Who is your neighbour? dentist? ask for free implant. doctor? ask for free surgery. car mechanic? ask for free engine rebuild. Want to be nice? offer them help selecting decent (not lenovo) replacement, or an older hand me down.

I think you're taking a very mercenary view here.  Sometimes doing something nice for neighbours pays in dividends not measured by dollars.

Let's just focus on helping Lomax achieve his objective and leave the accounting to him.

[senso]

you can donate five bucks or something

Erm, ok. So let me get this straight: these guys offer pirated copies of proprietary schematics - and they want me to pay for access!? That's... a little... greedy? 

elvikom.pl isnt some random chinese/russian pay $20 for one pdf outfit.
"these guys" run one of the better laptop repair forums where you can get good advice even when you are in top 1% of component level repair specialists in the world. You can either contribute by helping others with problems, uploading diagrams they dont have yet, or with your mums CC#.

quoting Louis might sound cool in your head, but in real world you will pay or go pound sand.

edit: simpler option is to find broken laptop on craiglist/ebay and swap components

http://www.ebay.com/itm/Lenovo-G40-30-80FY-BAD-Motherboard-As-Is-384-62-/291613065658

You can help if you can write in Polish or whatever is the main language on elvikom.
I could help them to gain points to download some datasheets, but I cant comment, and "helping" via google translate is not helping at all.
Almost all laptop repair forums have those shitty politics of post to gain points or pay to download a pirated datasheet.

Yes, servers are not free, but I would hang around a forum if I could post and help and upload my own files if they where more open, almost all of them due to this politics are filled with spam posting or begging to PM then a link to download.

I think that Louis is a bit crazy, rambles a lot, but its is own way..

That board is another Quanta/Phoenix special aka equal to tons of crappy Toshibas.
Get a schematic and you discover that around those touchpad buttons are the mosfets that gate the 5v and 3.3v for the whole board, made that way so there is a higher chance of frying the board with a bit of moisture from the touchpad holes, designed to fail.

I have already replaced so many mosfets in that general area.
But it seems more like that board went to swim around in wine, might have a looooot of broken components.
And you also have at least 3 corroded vias, that might be a bigger challenge.

[Lomax]

This is getting out of hand. Did anyone look at the photos?

[dfmischler]

Did anyone look at the photos?

Yeah, we all looked at the photos.  Did you ring out the vias?

[Lomax]

Just to correct some of the fallacies in this thread, first the general situation:

• Yes, it's a shit laptop, positively awful, but it's what I'm dealing with
• You can buy these laptops new for about £250
• My neighbour is a semi-retired author, with little money and a healthy appetite for wine
• He is also one of the few people in my neighbourhood I can have an intelligent conversation with
• The laptop was given to him by a client of his, so that he could do some writing for them
• He is embarrassed that he has ruined something that was given to him and doesn't want to tell the client
• I have advised him to get a different laptop, not least because of the poor keyboard
• I have also offered to help find him a used Thinkpad for £100-150, but he's basically skint
• I hate throwing things away that can be easily fixed
• I am very much against the low quality/short life-span economy we have adopted
• I do not do laptop repairs, and have no plans to "get into the business" - but this one I think I can fix
• I would have already tried repairing it if I had any suitable SMD parts to hand
• Electronics is a hobby for me, though I have worked in industrial automation and exhibition tech

About the laptop and the damage:

• The motherboard has been carefully cleaned and then inspected under a microscope
• The damage is isolated to two small areas (A & B above), involving a total of five components and two vias
• The components are
     
  • In area "A"
          
    • One dual Schottky diode (identified)
    • One resistor (should still be measurable)
    • Two corroded vias (the other pads are just unpopulated pads / test points)
       
  • In area "B"
          
    • One large-ish capacitor, relatively intact
    • Two smaller capacitors, one having lost a terminal
       
• There is some track damage in area "A", but it's quite small
• The two vias may turn out to be problematic, but we don't know that yet
• I do not want to power up the board in it's present state
• The two smaller caps look much like they're used for noise filtering (two in parallel to the same pad)
• An educated guess as to the value of those caps is probably "good enough" (10nF + 100nF?)
• The larger cap I would need the schematic to see what it does
• But it should still be possible to make a guess based on size (1uF?), which again may be "good enough"
• It may also be possible to measure it
• It may also be that there's actually someone here who knows enough about laptop repair to be able to help
• It may also be that there's someone here who has one of these boards in their trash-bin and can check it for me
• It may also be that there's someone here who has access to the schematics and can provide a definite answer

Possible outcomes:

• If the laptop dies as a result, nothing will have changed: it is already dead
  
• If it only works for a while before dying completely, so what - it's a crappy laptop
  
• If it runs but is too unstable to be usable, so what - it's a crappy laptop
  
• If it works just fine and continues to do so for a long time then great!
  

It is clear to me that I should never have posted my question here - too many smartasses who live to preach and spend more time bragging and telling people things are impossible and/or wrong than doing actual work. I would kindly ask that you refrain from posting in my thread unless you have something concrete to suggest - please go have your "I'm the best in the world on laptop repairs" wankfest somewhere else. Thank you.

Edit: Correction; there are two corroded vias in area "A", not one as previously stated.

[senso]

IF you can repair the vias, grab a diode from anything, even a PTH with bent leads will do.
The caps are more or less optional, it must boot or try to boot after you change the diode and repair the vias.
The caps will most likely be 100nF ones.

[Lomax]

IF you can repair the vias, grab a diode from anything, even a PTH with bent leads will do.
The caps are more or less optional, it must boot or try to boot after you change the diode and repair the vias.
The caps will most likely be 100nF ones.

Fantastic. Your username is very fitting, because you're the first person to make sense here. I've already found the exact part for the dual diode (£0.15 from Mouser), but since I have no SMD passives I thought I'd get a range of decent quality resistors and (ceramic) capacitors as well while I'm at it. This has been on my mind for some time, since through-holes have gone out of fashion. However not even that seems to be a straightforward task. I am starting to feel a little demoralised. Now about those vias, what would you do in order to try and restore them? Having never dealt with this problem before, what I would do is remove the old components and thoroughly clean the area with flux and fresh solder, then I'd place a small drop of solder paste on each one before heating them up past the melting point with a hot-air pencil. Does that sound reasonable?

Edit: There are no components on the reverse of the board under area "A", so a decent amount of heat can be used.

[Ian.M]

Err NO.  A via tented with soldermask doesn't have a readily solderable inner surface, even before the corrosion.  You'd need to look if there is any pad the other side, and if so, check continuity.  If its still good, make sure its clean and dry and apply a dab of lacquer to seal it.

If its bad your only realistic hope without significant extra resources, is if the inner layer connection to the plated barrel and from the barrel to the bottom pad is still intact.  It *may* be possible to clean it out well enough to get a fine strand of wire through it and solder that to the top and bottom pads.

Otherwise, short of milling down the PCB laminate to access the inner layer connection (see http://www.circuitrework.com/guides/5-3.shtml, your only remaining option is a jumper wire to where ever it re-emerges on a surface layer. If its on the opposite side of the board, well the via's FUBARed anyway so you can drill it for the jumper.  Of course, if you cant trace everywhere it goes, you've got a problem, so we are back to needing another board with that area undamaged, or an accurate schematic.

[Lomax]

Err NO.  A via tented with soldermask doesn't have a readily solderable inner surface, even before the corrosion.  You'd need to look if there is any pad the other side, and if so, check continuity.  If its still good, make sure its clean and dry and apply a dab of lacquer to seal it.

If its bad your only realistic hope without significant extra resources, is if the inner layer connection to the plated barrel and from the barrel to the bottom pad is still intact.  It *may* be possible to clean it out well enough to get a fine strand of wire through it and solder that to the top and bottom pads.

Otherwise, short of milling down the PCB laminate to access the inner layer connection (see http://www.circuitrework.com/guides/5-3.shtml, your only remaining option is a jumper wire to where ever it re-emerges on a surface layer. If its on the opposite side of the board, well the via's FUBARed anyway so you can drill it for the jumper.  Of course, if you cant trace everywhere it goes, you've got a problem, so we are back to needing another board with that area undamaged, or an accurate schematic.

Ok, thanks. So the conductive sleeve in the via (or what's left of it) is not solderable? What are they made of then?

Edit: Or do you mean that the solder mask prevents making contact with the sleeve? If so you need to look at the photos again; those two vias are not covered by the mask - that's why they have been corroded!

[Ian.M]

The plated barrel of the hole is copper, but oxidised/corroded copper (or residue from corroded tin plating) wont take solder unless its cleaned to a bright metal surface. Its very thin to start with, and if its gone O/C then a full thickness annular ring has corroded away, so there isn't likely to be much remaining metal left down the hole.

Also, most solders shrink as they cool so will tend to pull away from any tenuous contact that is made with the edge of an inner layer, and there isn't likely to be enough joint area to resist the forces involved.

If the corrosion is localised to the corner between the pad and the barrel as described and any inner layer connection isn't damaged, its salvageable as described by soldering a wire or rivet through the hole.  The same approach works for fully corroded vias if there are no inner layers.   

However, how are you going to connect to an inner layer track without milling the board to expose it when the only good metal left is an annular ring if you are lucky, or just the track end on one side of the hole, recessed into the laminate 100um or more from the hole wall, covered with a layer of corrosion byproducts?

[Lomax]

Basically, this is my mental image of what's going on with the vias. In the second "corroded" case, I would have thought it should be possible to form a solder bridge between the via and the tracks on the top. In the third case, I'm obviously SOL, but it's worth a try, no? Or have I fundamentally misunderstood something?

[Ian.M]

How are you going to clean up case#2 enough to get solder to take on the corroded end of the copper barrel?  Also, it isn't solid and isn't an insert like your diagram so the only area of metal to take solder is the edge of the thin ring of plating partway down the hole wall. As molten solder has a fairly high surface tension it tends to ball up and you are going to find it very difficult to get a very thin edge right down in an inside corner of a hole smaller than your iron bit to even take solder.   Your best bet for case#2 is to clean out the via right through very carefully with a very fine drill bit held in a pin vice using the least possible twisting motion, working from the good side and taking care not to cut into the plated barrel till you can get a fine strand of tinned wire through it and solder the wire to the pads top and bottom without covering the hole.  You should then be able to get the solder to wick through the hole from one side aided by the wire.

BTDTGTTS to fix salt-water damage, and the oldest such repair that I still know the status of has been in working order for nearly eight years since I did it.

[Lomax]

How are you going to clean up case#2 enough to get solder to take on the corroded end of the copper barrel?  Also, it isn't solid and isn't an insert like your diagram so the only area of metal to take solder is the edge of the thin ring of plating partway down the hole wall. As molten solder has a fairly high surface tension it tends to ball up and you are going to find it very difficult to get a very thin edge right down in an inside corner of a hole smaller than your iron bit to even take solder.   Your best bet for case#2 is to clean out the via right through very carefully with a very fine drill bit held in a pin vice using the least possible twisting motion, working from the good side and taking care not to cut into the plated barrel till you can get a fine strand of tinned wire through it and solder the wire to the pads top and bottom without covering the hole.  You should then be able to get the solder to wick through the hole from one side aided by the wire.

BTDTGTTS to fix salt-water damage, and the oldest such repair that I still know the status of has been in working order for nearly eight years since I did it.

Ok, many thanks. Some great tips there. Yeah, I know vias are tubes, and not solid cylinders; I just couldn't be bothered to reflect that fact in the (very quick) sketch. I'll clean things up and then take another look under the microscope - hopefully the corrosion is not very deep. I should be able to locate the via on the reverse so I can measure the link.

Edit: I've updated the sketch to reflect the tubular nature of the vias.

[Lomax]

Ok, so it seems I've completely misunderstood the nature of those two "vias" - after removing the components and carefully cleaning the "holes" with sharpened toothpicks(!) there is nothing at all left in one of them, and just a tiny speck of copper in the center of the other one. Underneath is just the PCB substrate. If these connected with any other layers it must have been a layer so close to the surface that it's basically at the same level as the base of the topmost tracks. Which doesn't seem to make any sense. Just how thin are the layers in a laptop motherboard? I think I'm about ready to give up on this laptop now but thought I'd post these photos in the hope that someone might explain what it is I'm looking at. There certainly are plenty of "normal" vias on the board, which although covered by the solder mask are clearly tubular structures (as confirmed by holding up the board with light from behind). Then there are these other things, which appear like little domes of solder - it is two of these that have corroded away (since they were not protected by the mask). Three uncorroded examples are also present in the pictures. But what are they?

[Ian.M]

Prepreg layers of FR4 (or other material) in a stackup can be very thin, down to    approx. 60µm.  We were hoping you weren't seeing a blind via that only goes down a few layers.
e.g. http://www.multi-circuit-boards.eu/en/pcb-design-aid/design-parameters/blind-via-buried-via.html

However as there is absolutely no evidence of a hole in the laminate surface, its almost certain that they are simply testpoints.  In that case, simply bridging them with a strand of fine tinned wire, bent to shape would be an adequate repair.

I think you've got lucky!

[Lomax]

its almost certain that they are simply testpoints

Thanks, that does sound somewhat promising! But having looked at the board I'm not so sure - there are plenty of exposed testpoints around but these have all been gold-plated (apart from J5 in the photo which I partially tinned). And why would you put a blob of solder on a testpoint? There's something odd about those holes too; if there had been a copper pad underneath the solder I would have expected to see something akin to the other corroded pads - instead there's a perfectly circular hole pit.

Edit: Actually, they do look rather like the other pads.

[Ian.M]

The only circular hole I can see is the hole in the solder-mask for the possible testpoint pads.  Why some are solder covered and others are gold plated, is anyone's guess.  The one by the D15 legend is clearly *NOT* a via. Scrape the little bit of copper remaining in the one on the track that goes under the J5 legend.  I suspect it will come off clean leaving continuous laminate surface under it which will prove that's not a via either.

Then its just a case of guessing the value of the caps, replacing the components, patching the tracks, and hoping there isn't any unseen electrical damage. 

[Lomax]

Thank you, that's very helpful! I've never done this kind of work on a motherboard before - I've replaced leaky electrolytics, and I SATA modded my Thinkpad T43p, but this is pretty extreme for me. Which is another reason why I'm so keen despite the unremarkable machine it's for. I'm learning here!

Why some are solder covered and others are gold plated, is anyone's guess.

Could it be that the tinned ones are test points for board continuity and trace resistance/capacitance used during board assembly, and the gold plated ones are for testing populated boards? That would explain why they are tinned; they would have served their purpose at soldering, and their somewhat peculiar locations. I confess I know nothing about the manufacture of multi-layered boards, except that they have multiple layers - sometimes connected with "vias" I didn't even know it was possible to create "blind" vias - an interesting engineering problem! I'm guessing such vias would be inserted when only some board layers have been added?

Then its just a case of guessing the value of the caps, replacing the components, patching the tracks, and hoping there isn't any unseen electrical damage.

I've already identified the two components in area "A": a dual schottky diode and a 100k 0402 resistor. The capacitors in area "B" I'm going to desolder, and see if I can measure the two that still have somewhat intact terminals (by tacking some Kynar wire onto what's left). If not, I'm going to go with the suggested 100nf & 1uF.

Edit: I don't know what type of solder they've used but I had to set hot air temperature to 500°C to get it to melt! Seemed unusually stubborn, even for a lead free composition.

[Lomax]

I have managed to measure two of the capacitors now; the larger one (0603) measures 4.8uF and the smaller (0402) one with parts of the terminals intact measures 55nF. So I'm going to assume that I need one 4.7uF 0603, one 56nF 0402, and one 100nf 0402. Although it is impossible to measure the second smaller cap, their position on the board (both going between the same two tracks) strongly implies a decoupling/bypass role, in which case two caps of the same value would make no sense. Sound reasonable?

[Lomax]

I think I'll let the pictures speak for themselves here... 

[vze1lryy]

Good work man! Amazing stuff. You killed it.

These boards are designed to deal with burning hot chips that don't belong in laptops in them, so with a regular hot air station you will need a lot of heat to remove anything. I use 375c on mine for most work and go up to 400c for large ICs that have a bunch of corrosion on them on the JBC JT-A.

The same temperatures and airflow I use to do standard work on these boards, will leave the solder molten for over 20 seconds on a regular board. 

[Ian.M]

+1 for good work.   If Louis says you done good, you can take that to the bank.

[Lomax]

Good work man! Amazing stuff. You killed it.

These boards are designed to deal with burning hot chips that don't belong in laptops in them, so with a regular hot air station you will need a lot of heat to remove anything. I use 375c on mine for most work and go up to 400c for large ICs that have a bunch of corrosion on them on the JBC JT-A.

The same temperatures and airflow I use to do standard work on these boards, will leave the solder molten for over 20 seconds on a regular board.

Why, thank you! I am flattered It was only after watching some of your videos on YT that I felt confident enough to have a stab. Thank you for sharing your knowledge with us amateurs.

I have my hot air tool set @ 380c, and use leaded solder paste - this has worked well in the limited amount of SMD soldering I've done so far, apart from on this laptop where I struggled to desolder until I raised it to 500c. I'm thinking it might be the presence of a thick tin oxide layer that made it more difficult to melt. Re-soldering was done at a lower temp. The lead-free solder didn't end up as shiny as it normally does, probably due to residue on the board, but the joins look healthy under the scope. By far the most problematic step was repairing the track by "J5": it was next to impossible to position and hold the wire (0.1mm dia) in place, and get the solder to form a good bond with the track. I suspect there must be a better way! I know it looks blobby, but he amount of solder used is minute - I had to use the tip of a pin to apply it (seen in photo on the left)...

Five days later and the laptop is still working just fine

[Lomax]

+1 for good work. If Louis says you done good, you can take that to the bank.

Cheers!