12 volts onto a 5 volt line is bad! Let's unravel the damage
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- Опубліковано 14 гру 2024
- This is the machine that kicked off this entire series. I recapped it and accidentally sent 12v into the machine, and after learning everything I could about fixing Macs, this motherboard is finally working as well!
Part 0: • 0089 Troubleshooting M...
Part 1: • I severely damaged my ...
Part 2: • Video
Part 3: • This SE/30 has so many...
Part 4: This part! (The final part)
-- Links
Internal Macintosh diagnostics / test modes:
docs.google.co...
Original document on the Diagnostic protocol:
web.archive.or...
Replicated Schematics of the SE/30:
github.com/mis...
Mac SE and SE/30 PicoATX PSU adapter:
github.com/dek...
www.tindie.com...
RGB2HDMI:
github.com/Ian...
TechStep Photos:
appletothecore...
TechStep Replica:
ko-fi.com/s/aa...
Adrian's Digital Basement Merch store:
my-store-c82bd...
Adrian's Digital Basement ][ (Second Channel)
/ @adriansdigitalbasement2
Support the channel on Patreon:
/ adriansdigitalbasement
My GitHub repository:
github.com/mis...
-- Tools
Deoxit D5:
amzn.to/2VvOKy1
store.caig.com/...
O-Ring Pick Set: (I use these to lift chips off boards)
amzn.to/3a9x54J
Elenco Electronics LP-560 Logic Probe:
amzn.to/2VrT5lW
Hakko FR301 Desoldering Iron:
amzn.to/2ye6xC0
Rigol DS1054Z Four Channel Oscilloscope:
www.rigolna.co...
Head Worn Magnifying Goggles / Dual Lens Flip-In Head Magnifier:
amzn.to/3adRbuy
TL866II Plus Chip Tester and EPROM Programmer: (The MiniPro)
amzn.to/2wG4tlP
www.aliexpress...
TS100 Soldering Iron:
amzn.to/2K36dJ5
www.ebay.com/i...
EEVBlog 121GW Multimeter:
www.eevblog.co...
DSLogic Basic Logic Analyzer:
amzn.to/2RDSDQw
www.ebay.com/i...
Magnetic Screw Holder:
amzn.to/3b8LOhG
www.harborfrei...
Universal ZIP sockets: (clones, used on my ZIF-64 test machine)
www.ebay.com/i...
RetroTink 2X Upconverter: (to hook up something like a C64 to HDMI)
www.retrotink.com/
Plato (Clone) Side Cutters: (Order Five)
www.ebay.com/i...
Heat Sinks:
www.aliexpress...
Little squeezy bottles: (available elsewhere too)
amzn.to/3b8LOOI
--- Instructional videos
My video on chip removal without damage:
• How to remove chips wi...
--- Music
Intro music and other tracks by:
Nathan Divino
@itsnathandivino
It's a shame you said this series didn't do as well as some of your other videos, Adrian. These lengthy sagas of in-depth troubleshooting are some of my favorite content of yours! I'll keep donating if you keep making them, views be damned. 😉
I have to agree that I seriously love these videos and I also appreciate the amount of work that goes into making them.
I don't even own an Apple, and I love this series for the evidence based approach to repair.
For me, it felt like a lot of copy/paste from a spreadsheet and reciting of hex numbers. Useful if I wanted a tutorial, but less appealing as entertainment. A difficult line to walk. Can't please all of the people all of the time. Still a happy subscriber!
I also love this style of series!
Maybe when the entire series is finished people people will be more lilely to watch since the series can be binge watched?
Not much nostalgia outside of the USA , they could not compete with cheap Euro/Asian PC's, here a apple was for work not play.
I love the black and white future edits. I just keep thinking in my head of the meme, "It was at this moment that he knew, he f*cked up".
Hahahaha yeah!!! 🤣 Exactly!
I was thinking the same thing.
I was getting Dukes of Hazzard freeze frame vibes ("Bet those Duke boys wish they had a parachute about now!"), but then again je suis un homme d'un certain âge. I like the new meme a lot.
The edits at least help me not scream into the screen "nooo you forgot to check the TX" ;)
It reminds me of Pole Barn Garage, he too does future edits like that
The best thing about this series is turning an otherwise big mistake (frying half the mobo with 12v) into all sorts of new learnings, not just for these boards, but also for anyone with an old Apple computer. Bravo sir.
27:33 - I hereby vote for more Gray Adrian! He's hilarious!
Totally agree 😂 very The Wonder Years esque, love it!
Gradrian the Narrator
Board: PLEASE LET ME DIE !!!
Adrian: no.
The stamina is impressive! It was a pleasure to follow along, the more with the detailed explanations and deductions.
These videos are absolutely fantastic, because I have quite a few SE/30 motherboards that I need to fix and I've got renewed enthusiasm for tackling them again now.
That's awesome!! It's exactly why I make the videos, in hope they might be useful to other people.
Amazing work! This series was a delight to watch. Thanks!
Had to laugh at the zif adapter nest 😂 but it works!
The 8-bit guy: let's design and order adapter PCB
Usagi Electric: let's mill adapter PCB
Adrian: BODGE WIRE OCTOPUS!
Anyway, congratulation on the victory, and what a victory it was!
If it looks stupid but it works...
I thought the 8-Bit guy started with: Let me poke that with a paperclip.
@@NotIThe did, and the guy forgot Shelby from Tech Tangent
There is a time and a place for all sorts of fixes.
Adrian: let's do some diagnostics and only replace what needs to be replaced.
Usagi Electric: what Adrian said!
8-bit Guy: let's bypass the power switch on this super-rare IBM computer using a paper clip, and make sure not refer to any schematics or pinout diagrams.
I have next to no interest in apple pc's but enjoy watching the techniques and repair philosophy you follow.
Thanks Adrian.
You deserve more views.
Thanks -- I do try to show that the techniques are the same no matter what the system is. :-)
Same here, The Amiga was my home computer for a long time and would never give Apple house room , but I've done so much fault diagnosis on all sorts of equipment, mainly on Radar and Sonar equipment and custom CPU systems Z80, 8085 etc . that I can see most of the techniques I was taught being used here. Very well done, and it's a wonderful learning tool for any engineer to work through.
Andy
I feel the same. I watch for the sheer enjoyment of seeing an old machine come back to life. But I would NOT ever want to use that old thing. So I am glad that Adrian is doing all the work and I don't have to. And I don't have to figure out what to do with the old machine afterwards either.
Same here
This has to be in the top tier of retro repairs on the internet (not just UA-cam!)
I'm so glad you got it working, but really the journey of discovery with this series has just been amazing, thanks for taking us all along for the ride!
As an SE/30 owner, I really appreciate your findings. They will be handy when my machine develops a fault.
Ok, I want to make it loud and clear that I LOVE long, detailed “ride along” trouble-shooting g videos! I’m 70 and I spent my entire career troubleshooting electrica, electronic, and computer problems. I synch right up to Adrian’s critical thinking methodologies, and I ALWAYS learn something new on every video, whether it’s tools & techniques, or about a particular model of computer.
This series was great from the standpoint of “Don’t give up !” I’m very proud of you for that. I’m not very experienced with Macs. I did go through a period where a client had a number of older Macs interfaced to scientific instruments in a biotec laboratory. I was mostly supporting their LAN & Internet connections, but there was a bit of keeping the Macs happy and contented. There was an SE/30 sitting in the storeroom, retired, so I messed with it a bit. They probably would have given it to me, but I didn’t think I was interested in it at that point. Ah, for the lack of foresight!
Good job, Adrian! 💪
I only used computers, never repaired one on this level, i have no solder skills, i never used an oscilloscope.
And still here i am watching these videos and been fascinated about them.
Welcome to the club!
Adrian's videos are wierdly satisfying, I think it's his soothing personality as much as his incredible skill.
Hi Adrian, I've been watching this series very closely because I have an SE/30 that I haven't been able to repair after leaky caps and light battery damage. I was hoping to get the information I needed to diagnose and fix the board. I almost stopped watching when your repair fried that first board. Sometimes it's painful to watch you make mistakes, even though armchair technicians like myself make plenty of similar or more serious mistakes. I'm glad I kept watching because the information you shared including the reconstructed schematic and spreadsheet on serial port diagnostics is just what I needed. Knowing that others struggle to repair this era of macs and that it is possible to work through difficult failures makes me want to try again on my board. Thanks for sticking with this repair.
Adrian this is one of the best series I've seen from you it was so interesting to see how you fixed so many problems and slowly diagnosing everything piece by piece Good job
As others have said, the messages from Editing Adrian are golden. At around 27:30 when you inserted a quiet "Oh, how wrong I am" I actually laughed out loud. Thanks for all the great videos. You've helped me on my journey to fix first, replace only when necessary. Thanks!
This was a great series!! I hope it does better and your views increase.
This was great to watch and since I have been subbed to your channel it’s always been fun to watch your troubleshooting abilities.
Cheers!!
Yesss, I love this series! Having refurbished an SE/30 of my own earlier this year, it's super interesting to see all the bullets that I dodged and the problems that I fortunately did not have to deal with. I also really appreciate the scientific approach to diagnosis, it's very educational and definitely will help to give me ideas when doing hardware repairs in the future.
As someone who's only really super familiar with the inner workings of 680x or maybe even 6502 based systems, this opened up a whole 'nother world for me, and I was actually quite hooked on the little series! I really hope you make more of these long troubleshooting videos, as it was quite satisfying and engaging to watch.
Very well done, sir. I’m not sure about everybody else, but I absolutely loved this series. I don’t even have an SE/30 but your thought process and explanation of everything you’re doing makes perfect sense and is much appreciated. My SE FDHD is working just fine but I will eventually need to recap.
"Oh how wrong I am." Thanks for your honesty, it makes your videos so much more human.
I was litterally thinking, "but you're going to check the receive line anyway right?" then you did your post commentary. lol
Chiming in about the plcc soldering again. Solder paste is not the best rework technique, I stopped doing that long ago. i recommend getting flux that louis Rossmann uses (that is no-clean and way better than rosin). Apply flux to all pads. Then apply new (leaded) tin to the pads. With that flux around the tin will apply evenly when going slow enough. Gnd pads sometimes require special attention. When the result looks even, apply more flux. Place the chip. If necessary tack doen on one or two legs with the iron.Then heat up the entire chip, its legs, and the surrounding pcb area. Go in circles. Your nozzle was way too small, use a larger one and enough airflow and heat (the trickiest part as the right amount of heat depends on board stack, practice level and heat gun - I use more flow and almost max heat to achieve the shortest possible process). You will see when the chip sinks down. Its worth practicing this on dead boards first. This also works with larger chips like qfp144. You do not get bridges this way and a more even result.
Absolutely spot on. I do a lot of SMT work, and getting the right amount of solder on the pads (whether by paste, or existing “tinning” of the pads) is key to getting capillary action to do your work for you - pulling the chip into place and down against the pads, and getting the solder to wick up the sides of the IC pins and form a nice solder fillet without bridging across the solder mask to adjacent pads.
It’s amazing how little solder it takes to attach modern SMT parts. For a manufacturing run of thousands of boards, it may take only a pound or so of solder paste. Each joint takes only micro-grams worth of solder.
Loved this series! This and the Plexus have been my two favs! I know you gotta give the fans what they want, but keep tossing in some of these now and then, they’re really educational.
The part where you had a theory about the RAM and then tested it with a specific amount and it worked... blew my mind.
Glad that poor abused motherboard was brought back to life. Great that the diagnostic mode over the serial port is now understood better. Enjoyed the series.
1:12:09
Adrian: “Well, the board is fixed.”
The humble VRAM chip: “Omnissiah, grant me strength.”
Hats of to that dead 2cx for being an organ donor for pretty much everything! Might as well go back and pull the CPU to replace the one you used from your stash.
On the 020 and up, you use those special F-line instructions to talk to the FPU/PMMU. If the copro isn’t present, the instruction acts like a trap, allowing the OS to jump into a replacement routine. Seeing as the SE/30 was never meant to operate without an FPU, it makes sense that they didn’t include a routine for that!
I've never owned an apple product, probably never will. I did watch every second of this series though and I've never been so invested in seeing an Apple computer startup as with this "12v" machine of yours! I love the memory chip adaptor you made, if it performs exactly as it should I think you should leave it just for the visual effect on the board itself, its cool!!
Never let Adrian near Data Line 31 ever again! 🤪 . Seriously though, good troubleshooting series!
Great Series.... Thanks for sticking with it to the end......
That was a great series. Nice work Adrian.
I don’t own any vintage computers, but I thoroughly enjoyed this series. I enjoy your sleuthing. Great job.
I for one love these long form videos! I don't always have time to watch them in one go, but I do love watching them in full! I do also know however that they are videos that tend to do less good because I think the average attention span isn't as long as us who love these long videos haha. There's a reason why every platform has some form of short videos nowadays (YT shorts, TikTok, Instagram Reels etc.). I would love to see more long videos like this, but I also understand that shorter videos are needed to keep the algorithm happy. I think a mix of short and long videos would be a nice middle ground. Mostly shorter videos, and the occasional long boi :)
Keep up the good work, this series was a blast to watch!
I’ve learned the most from causing my own f-ups. It’s super frustrating when silly accidents happen, but I’m a better tech in the end. Congrats on the victory and bringing the board back from the dead Adrian!
Wow, wow, wow, Adrian!!! I'm so incredibly excited!!! I've learnd again so much in this video. Have many thanx. Georg
Out STANDING Adrian.. wonderful series.. what a really great learning experience for us all with this one.. really great, I am elated!!
Thanks for the series Adrian, I for one really loved it!
Awesome perseverance! This has been an epic struggle, but you did it! I learned so much from this. Great job, Adrian!
You must be so relieved. Amazing troubleshooting as always. 👍
Really one of the best repair videos!
The fault finding is epic! Well done!
A trick I learned from northridgefix is to measure some power lines of good boards using the diode test mode on the multimeter. Noting the voltage drop, when you recap the board a short to a data line would likely give a different voltage drop on 12V indicating a problem.
Another trick when doing work on main boards is to use the flir camera and give a quick on/off power up/power down. If some parts shoot up in temperature you might be just in time to prevent permanent damage.
I am STUPIDLY excited about this video, been loving the series! Thanks Adrian!
My introduction to computers back when I was in high school when machines like Classics, Classic II’s & LC II’s arrived at school from Apple, seeing this SE/30 gave me joy. Your recapping error gave the vintage Macintosh community a new diagnostic tool so more vintage Macs will get fixed and loved again instead of becoming e-waste
Congrats on the repair! What an in depth repair. I know I've learned from this series, I'm sure you learned a lot too!
I absolutely loved the whole journey and learned a lot not only about macs, but electronics in general.
Thanks for the amazing learning, Adrian!
That's what I love about you is how to diagnose and identify the problem and fix it. Nice job, buy the way. I love watching your long videos. Keep the wonderful working
Wow I loved it. The Drama Is Real. Congrats on getting the board sorted!!!
"SE repair series" More like SE breaking series :D Nah, just kidding. I love these. You're HW debugging skills always amaze me. Keep making great videos!
what a journey! your diagnostic have definitely leveled up. congratulations!
Possibly your best series of videos to date, but you turn out such great content that I'm spoilt for choice.
The whole series was extremely educational and entertaining, 2 words that you don't often see in a sentence. I hope your future videos will be just as good.
Your persistence is admirable! Greetings from Münster in Germany :)
Congratulations! I love watching these videos.
I ALWAYS love watching these type of videos. It's kind of relaxing and fun when I need to just sit and relax.
I'm glad you did all this because I have an se30 that badly needs repair and up until now I thought it was a lost cause
Amazing! Thank you. I always learn so much from your videos. The BEST channel on Apple II and Macintosh repair. I followed one of your Apple II repair videos and managed to fix Rev 0 Apple II.
This series of board repair was really interesting and I enjoyed watching it. Thank you - keep them coming!
You could say I'm into it...I literally cheered when you got the video going last episode!
That's awesome. 🎉 It's so rewarding to get these old things working again.
Bravo! Nice job getting the video chip working using a Frankenstein mod of sorts. It doesn't have to look pretty so long as it works.
Kudos for saving this board and teaching us how to use the diagnostics
Good work on getting this board fixed. Experience is the harshest of teachers but the best at creating knowledge.
Ultimately the 12v-pocylpse made for a far more interesting repair series than the original repair would have been.
I’m so glad you pushed through with this one, it was very satisfying to see the board working.
I will likely watch them through a second time and I’m not even that interested in retro Macs.
I do appreciate learning about retro tech and how innovative they were at the time and the fact they are repairable in our currently disposable world.
I enjoy the amount of effort you put into repairing these items. Most world just trash and move on.
I really appreciate how you stuck with that seeming cursed board all the way through! Plus you gained a bunch of personal knowledge and helped expose Apple's advanced troubleshooting techniques for those machines.
I have to wonder if other OEMs had similar tools for any other machines. I did break/fix warranty repairs on laptops & PCs for almost 20 years from the late 90s to the mid 2010s for a bunch of different manufacturers. It always frustrated me how the PC OEMs completely discouraged component level diagnosing of issues in favor of the parts cannon approach for warranty work. While simultaneously penalizing techs for using too many parts.
This became especially true in the 2000s when all the major PC players changed how they viewed warranty repairs. The perception became warranty repairs were only a cost to their bottom line. Previously it was a value add to their customers and a good way to keep customers happy. They all figured it was cheaper to get new customers than keep existing ones (personal, small business & corporate alike) happy.
adrian, watching your repair videos is such a delight in my day ^_^ - especially this series when you made a fault and do everything to resolve lets me remember one line of a famous (trashy) movie called "galaxy quest": "Never give up! Never surrender!" - thumbs up and keep up the great work!
Liquid flux!
Adrian, cover all of the pins in liquid flux, run a soldering over all of them, like magic you will have a perfectly soldered SMD chip with no bridges.
You can be as sloppy as you want, bridge all of the pins. Put liquid flux over all of them, BAM! Perfect solder job. Smokey but it works.
This is how I learned in a Sony training class almost 30 years ago. Before hot air rework was thing.
Adventures on the 12 Volt Rail - sounds like an 80s movie! This is making me want to dig out my Mac II motherboard. No voltage adventures there. Just let it sit too long and the caps corroded it. Managed to get it to chime but no video. Probably my poor SMD repair skills.
Ah well you know you can bust out a serial cable and hopefully try to get some answers from it. It's like R2D2 talking to the Death Star computer :-)
@adriansdigitalbasement I'm no where near as smart as R2D2. It'd be more like Roomba talking to the Death Star lol. I'm digging through your videos now to find your technique for bodge wiring on these tiny traces. I've done it but I have a hard time avoiding other traces.
@@TechTimeTraveller I predict a pretty funny sketch!!!! R2D2 can come by and knock the Roomba out of the way and get real work done 😂
Loved the video series, very interesting deep dive and a shining example of a data-driven diagnostic approach to repair!
There is nothing as satisfying as elaborately fixing your own mistake (the 12v to the 5v). Well done, you should be proud. Please clean those boards better.
What a battle! Great patience and deduction.
I salute you! Only a true troubleshooter would go to your lengths to get the macs working. And even more, you even got the debugger operating too.
heck yeah! crystal quest! for the past few months you're videos have been inspiring me to fix my color classic and se's. i think it will happen soon.
Excellent series! I've not even owned a MAC ever. But I so enjoyed this anyway! Thank you!
Yay! Loved the SE series. TY
That serial debugging feature is magical. Arbitrary code execution over the wire is going to enable some cool diagnostics!
Another vote for you to give Louis Rossmann's channel a look for the best way(s) to deal with SMT. Note, you will need to look at his older videos as he now, on the same channel, is doing more "right-to-repair" and right-to-own type videos now. In any event, solder paste is really for when you have a stencil to overlay the pads and then squeegee the paste, evenly onto the pads.
Without a stencil, clean the pads (solderwick followed by IPA), add flux, drag-solder fresh solder onto the pads, hot-air (in a swirling motion...you don't want to cook the board or have steady intense heat and watch out for blowing other parts off) and place the part with tweezer or the like. The part should feel like it self-centers and even "dance" while you are swirling the hot air. Again, seeing a Rossmann video is going to be 1000 times better than reading words as you can see it actually done and how it should look/feel.
Congratulations working through this problem. Your whole thought process was impressive as was the perseverance. I like the long-form working through the problem videos.
Hats off to you for the persistence, and I really enjoyed that... But I was hoping the lesson learned was that if you're taking off electrolytics, replace them with electrolytics!!
Thanks!
I really appreciate the support! Thanks! 👍
I can't wait to try the serial diagnostic mode on my broken IIci, could never figure out what the problem was. Hopefully it'll shine some new light into the board! Thank you Adrian :D
Fun diagnostics process. I'm impressed by how much was learned.
This was an incredible journey! The start of this saga was my first encounter with this channel, and I'm impressed with the detailed breakdown of everything that happened along the way. After the first video, I was very invested in seeing what happened to the damaged board, and had to watch the whole thing through right away.
My perspective is more from the programming side than the hardware side, and it was especially fun to see that tiny 68k assembly program loaded via test mode for the video memory diagnostics. Looking through my old MPW installation, I see that there are two different matches in MacErrors.h for error code 11; one is "sdmInitErr", with the comment "SDM could not be initialized."... Not sure what that one means, but "dsMiscErr" looks a lot more likely, with the not-so-helpful description of "miscellaneous hardware exception error".
Very satisfying to see the progress as everything got put back together. I'm amazed that substitute VRAM chip worked as well as it did, and the way it changed the uninitialized video pattern at startup was such a cool twist.
Thank you Adrian for this series, it has been very nice to follow along on your journey! Just one tidbit I have not heard you mention: there is another reason that ceramic capacitors are not a good idea to use and that is their capacitance is voltage dependent, I can't provide direct links due to UA-cam censorship but if you Google for this you will get some good articles: capacitance voltage dependency ceramic capacitors
I've talked about it before and it is something to consider. I've done a bunch of testing and this is mainly an issue with circuits using the caps for timing (RC, etc) as the values being off cause issues. But for bulk capacitance like what's happening here or AC filtering like on the audio circuit, it doesn't matter at all. As long as you check the datasheet to make sure you aren't getting 4uf when it should be 50uf.
Kudos for your tenacity, great deducing.
It's quite fun watching Adrian diagnose and fix gnarly problems.
Hi Adrian. Solder paste is - essentially - eensie-tiny balls of solder in a rosin paste. It’s usually used with a mask; this is a thin sheet of etched steel or brass with holes where the pads go. You lay it onto the board, align it, then spread the solder paste onto it so the paste goes into the holes. You scrape it with the edge of something flat and straight, like the edge of a credit/debit card, or a small metal ruler, and this forces all the paste into the holes. Then you lift the mask and use hot air to solder the chip in place. Afterwards, you just clean the paste off the mask with IPA.
The simplest solution is to design a PCB with just pads that fit the (dead) PLCC chip, and have the traces extend out to the edge of the board (like the edge connector on an ISA-slot PC peripheral). Then send the design to JLCPCB, or PCBWay. They generally require a minimum order of 5 boards, but this is okay, as you can use them to practice using the solder paste and mask. Also, if you have a spare good chip, you can solder that to one of these boards and use it as a test jig! HTH! 😊
You don't need solder paste. You can clean the pads, tin them, then add flux and then sit the chip on top and heat it with hot air until it slides into place.
This is the way I've learned to solder those types to chips. It works well.
One addition: You can't hold the chip down while applying the hot air, or it won't slip into place. If the chip tries to fly away, the air flow is too high anyway.
I’ve totally done this before. Additionally the main problem Adrian had with the soldering job he did was with the lack of flux.
Awsome job Adrian keep up the good work😊
Well done! As a rule, you should not rely on solder mask to provide electrical insulation. That's not it's purpose; it is very thin and easy to scrape off. Vibrations or any relative motion could eat through and create a short to any underlying copper.
Just realized I'm learning from you, things I didn't have the patience for as a kid.
I was waiting to see what would come of this board. Glad to see it finally working. It was certainly a journey.
Hi Adrian, with the solder paste, make sure you keep it in the fridge when not being used. If it goes above about 10c it will not work as well and things like the bridges you're getting will happen. Good job on the technique! Cheers
Where is the 2 thumbs up for an epic series? Amazing saga of troubleshooting and new discoveries. Brilliant! May you get 100,000 high 5s. What can we get you to kill with voltage next?
"Oh how wrong I am" - I HAD to laugh out loud at that!
from some of the videos I have watched I think you on the right track, Yes the chip will move slightly when it solders
I always love these videos, Adrian! Really appreciate all the videos. Commenting for the algorithm. 😃
Your technique looked much improved for the PLCC removal/reinstallation, glad you reported it seemed to be at least somewhat easier. You can, in fact, get away with _even less_ solder paste than you used - dragging a full line across the pads like you did was the right approach, but a thinner/narrower line of paste will give less opportunity for excess solder to bridge between adjacent contacts. When you're doing the "line of paste" method like that, consider that all the solder _between_ the pads will get sucked onto them, so you actually have more solder down than you think. It doesn't take much to properly attach the pins!
If I'm getting too much paste out of my syringe and it's hard to control, I'll sometimes squirt a bit out onto some aluminum foil and then use a micro (usually slotted) screwdriver or a wooden/plastic pointed tool to transfer that onto the pads. This is a bit tedious for larger chips like you're doing, but gives much better control over exactly how much paste you lay down and where it goes.
Sometimes the chips "float" into place, sometimes they don't; it depends on the chip size/weight and exact pin layout, but I try to avoid pressing down on the chip as this can squeeze solder out from below the pads into adjacent ones. Instead, if you need to adjust the position, just poke it gently from a side/corner without applying any downward pressure. If the chip is moving around too much from the hot air, turn the airflow down or adjust to a larger nozzle so the air velocity is lower. You might need to bump up the temperature a bit to compensate so that things melt quickly enough if you do this.
if the IC seems to not self align, You can try to push it very gently to see if they back to right position. Using lot of flux helps with self alignment and solder bridges
Congrats but we are revoking your 12v license.
1:01:07 if memory serve, System error 11 is the F-Trap, aka FPU access. So the assumption would be correct.
Thanks for the video and the information about howto repair a Mac pcb