This Mac nearly had me beat! It fought hard but I got it in the end.
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- Опубликовано: 30 апр 2024
- In this video I repair a Mac 512k motherboard with an unknown RAM expansion card on it. In part 1, we looked at two Mac motherboards with unusual RAM expansion cards. The Mac 128k motherboard worked, but I left the Mac 512k motherboard for another video. This is that video! Figuring out what was causing this motherboard to not boot and display video issues required me to study schematics and try to understand the architecture of these early Mac machines, and it paid off!
Part 1: • Mac motherboards with ...
Part 2: This part!
-- Video Links
ROM Matrix:
docs.google.com/spreadsheets/...
Sad Mac Error codes:
tinkerdifferent.com/resources...
Macintosh 128k technical documentation:
bitsavers.informatik.uni-stutt...
ROM Disassembly:
www.bigmessowires.com/rom-ada...
PicoRC:
github.com/dekuNukem/PicoRC/b...
www.tindie.com/products/dekun...
Adrian's Digital Basement Merch store:
my-store-c82bd2-2.creator-spr...
Support the channel on Patreon:
/ adriansdigitalbasement
Adrian's Digital Basement (Main Channel)
/ @adriansdigitalbasement
My GitHub repository:
github.com/misterblack1?tab=r...
-- Tools
Deoxit D5:
amzn.to/2VvOKy1
store.caig.com/s.nl/it.A/id.16...
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.com/products/digi...
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.com/item/33000...
TS100 Soldering Iron:
amzn.to/2K36dJ5
www.ebay.com/itm/TS100-65W-MI...
EEVBlog 121GW Multimeter:
www.eevblog.com/product/121gw/
DSLogic Basic Logic Analyzer:
amzn.to/2RDSDQw
www.ebay.com/itm/USB-Logic-DS...
Magnetic Screw Holder:
amzn.to/3b8LOhG
www.harborfreight.com/4-inch-...
Universal ZIP sockets: (clones, used on my ZIF-64 test machine)
www.ebay.com/itm/14-16-18-20-...
RetroTink 2X Upconverter: (to hook up something like a C64 to HDMI)
www.retrotink.com/
Plato (Clone) Side Cutters: (order five)
www.ebay.com/itm/1-2-5-10PCS-...
Heat Sinks:
www.aliexpress.com/item/32537...
Little squeezy bottles: (available elsewhere too)
amzn.to/3b8LOOI
--- Instructional videos
My video on damage-free chip removal:
• How to remove chips wi...
--- Music
Intro music and other tracks by:
Nathan Divino
@itsnathandivino 
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I honestly like the lighting in the Adrian After Dark videos. It feels more like chatting over a drink and sets the visuals apart from every other retro tech channel out there.
Screen looks more comfortable if not for circuit reading or detail.
Agreed! I really enjoyed the after dark ambiance. I definitely hope there are more of these to come!
Holy sh*t, all that explanation and schematics reading lead to "I'll just hold the mouse button..." and the system boots :D
If this were the 1980s it'd be an RTFM moment, but... Nearly 40 years later and the manual is lost to time...
I keep thinking Adrian needs a Flying Toaster plushy for the after dark sessions. It could be friends with Rammy.
@@logipilotJust a quick tip: It’s you’re, not you’r.
This guy never ceases to blow my mind with his diagnostic skills
I like the after dark format. Do more please. Thanks!
That was a tour de force in troubleshooting an unknown function. Well done!
For calcium stains (that's what hard water stains are), a mild acid works fine, just as with kitchenware. Citric acid is commonplace and sold as powder, so you can mix that up to the concentrate level you want.
Always satisfying to find the problem and get a board working again. I was surprised the motherboard wasn't tested without the RAM expansion board as one of the first diagnostic steps.
I like the Adrian after dark. It has a cool feel with the mood lighting.
Like hanging out with your buddy in a bar or tavern.
I was just thinking the same thing. Just a couple buddies shooting the shit about computers that they’re fixing. I dig it!
fantastic fault finding, well done on you persistance too. And I enjoy fault finding too, even after over a 40 year career in electronic engineering!
I sometimes wonder if the board designers watch this program and sit there laughing as you struggle to understand their work?
I had left Steve Wozniak a message a fair while ago to have them pop in once in a while to watch.
@@llwellyncuhfwarthenI don't think Woz worked on the Macintosh.
@@Toonrick12 Adrian has done Apple II diag/repair work. Woz would recognize some of that..
Brilliant deduction about the mouse button, very impressive!
When you first talked about the vertical lines, I was hoping you'd use their exact positioning to help you narrow down the failing RAM chip and sure enough, that's what ended up happening. It's so interesting seeing how close to the metal these older systems are where you can have a 1:1 correspondence between a hardware failure and the actual symptoms, rather than just the random crashing you get nowadays due to all the layers of abstraction between the user interfaces and the hardware itself.
Great Episode. I never ran across that card while supporting the 68000 Macs but I do remember that RAM errors were always annoying as heck on those, which is why any RAM error got you a spares replacement board and your board went to Apple for repair ( it was faster thus cheaper ).
I also remenber how I became the only shop tech who could work on Macintoshes.
Now to preface this, my father was and E.E. and actually has a very cool patent from the 60s that is a way to get 8 phone calls over a single radio channel, kind of a tdma sort of thing, and my Dad usually ran a TV repair shop, and so, I kinda grew up those.
So I'm trying to do a live power supply/display adjustment on a mac 68000 which means I've a mirror on the bench, and I'm reaching into the Mac to set the gain or whatever it was that made them bloom, and I keep getting tickled now and again by the high voltage, and I softly say "damn" each time, somehow that makes it not hurt.
The shop manager, call him Ed, goes "What's wrong" and I tell him "I'm adjusting the gain and I keep getting zapped, and I twitch and miss the setting when I get zapped".
Ed gives me this look, like I'm some kind of imbecile that must be pittied, and says " I'll do that " and takes over.
Oh Right, the customer was there waiting to pick the Mac up, and the screen was over bright and not too readable, that's what the isuse was, lolz , memories, like holograms, the more you excerise the memory, the more of it pops back.
So I go up to tell the customer "Just a few more minutes, the service manager is taking care of the adjustment" and walk back to the shop, when Ed screams "Fuck" and I see the Mac come flying across the shop, hitting something and the CRT goes "POP"
Ed claimed he got shocked, spasmed and the Mac took flight.
But because I'd worked on CRT TVs so much, I didn't (still don't) have the same reaction to getting shocked as most people, stun guns can make me laugh, and I can walk while being tased, not easily, but yeah, that's how the verry irritated Computerland GM declared that unless anyone else had high voltage experience I should be the only one working on CRTs.
Oh yeah, the Custome ended up with a whole new Mac too.
Lolz, I later built a jig with extended cables to let you safely do those adjustments.
When i was a programmer, i got my best work done between the hours of 1am and 3am. Quiet, no interruptions from the world, it was perfect for coding.
What an amazing 'whodunnit' bit of RAM detective work! I loved watching you finding the culprit.
1:00:10 you've could just count pixels between your line and line that motherboard RAM generates, and removed the chip that lives needed count of bits away.
Amazing skills Adrian! The second channel really deserves more contend like this one. Congratulations!
The “water stain” is quite likely calcium carbonate. As somebody else already noted, vinegar would dissolve it, IF you can tolerate the smell. If not, maybe you could find oxalic acid that will do the same with radically less odor. After the acid treatment (just a couple minutes), you should put the board through a dish washer cycle, and after that, flush twice generously with distilled water, followed by blow drying. Mildly warm, if you can produce such. A good long time!
Citric acid can be used as well.
Wow, that was crazy! Great Job! Thank you for sharing with us and the explanation! ❤
I love watching you problem solve your way through all of these repairs! It's so satisfying!
Watching this from Gresham... Love the repair videos and the logical deduction and creative solutions to find them. Keep up the repair videos and enthusiasm. It's very infectious.
Dang, great work! I love how you found the (well lack of) RAM test stuff in the ROM and the mouse down workaround for the add-in card
As always, Adrian, excellent video. And again, we learned so much. Thank You!
Just excellent logic and work! One of your best videos of all time! I don't care about MACs at all we never had them here in Greece, but I loved the way you approached the situation and even without a scope's help which is a tool most of us don't have, you figured out the fault!
Cheers, keep up the great work, Jim.
Isn't is such a great feeling of accomplishment when you find the code that figures out the bad chip? So good!
I really enjoyed the troubleshooting in this video. The repair videos are definitely my favorite.
Simply amazing. Love this kind of content. Thanks!
This was an awesome episode. Loved watching the thought process lead to that solution. My hat is off to you... as long as the east wind isn't blowing in from the gorge.
Your level of research, attention to detail and layperson explanation is AWESOME!
Thanks, Adrian. The After Dark segment has one of the BEST explanations I've ever seen about the dance between hardware and software in these early Macs (and even a bonus dive into 68K ASM!) Excellent, informative and riveting video. A Master Class in information-led diagnostics. ❤
Amazing work… great detective work.
I’m so glad that someone like you is rescuing these vintage machines!
This was one of my top favourite videos of yours. Maybe the top video due to your tenacity to troubleshoot it until you got it working. Over the years I have lost sleep not being able to solve a problem. I once took 2 months back in 2006 with technicians in both the US and Canada helping to try and solve a problem that seemed to have no solution. Then one night at 3am a thought popped into my head so I hoped in my truck and drove to my customers sight to try my fix and bingo it worked. It’s very satisfying fixing a problem like that.
Amazing work and I learned a lot from this video. Thank you for your detailed research and explanations.
Good job mate! Had fun watching.
Great job figuring it out Adrian thanks for video
Super funny and great video! I very much enjoy all the troubleshooting, congrats!!! well done!
There is a remarkable lack of flying toasters, but the black magic (pun intended) makes up for it!
Love the deep dive fault finding and the video format. Feel free to keep them going.
Awesome totally cool and well done, love your thought process with this problem.
I really enjoy watching your content in general, this one however was just one of the cherry on the top ones!
This was a great video, it was amazing watching you go through everything! I have almost no experience with Macs, and I certainly didn't work on them. My elementary school had Apple computers, and got a suite of Macs donated to them shortly before I left. It's always neat seeing the insides of all these computers I was aware of, but never got to truly experience. ^_^
I fixed some single pixel vertical bars like that on one of my SE/30. Just needed to repair a couple broken traces. Thanks for the explanation Adrian! I love following along with your repairs.
Awesome video Adrian, love the after dark stuff - amazing! 😊👍
What an inspiring video, great logic and persistence.
Yet another excellent video from one of my favorite RUclips creators (right up there with David at Usagi Electric and Ben Eater). Some of the mail call and similar videos may not get a full watch, but the deep dive ones like this are always worth the watch. Great start to a week vacation, and I even heard Adrian use my comment from his last after dark video in this one. :)
I really enjoyed this video. I also like the Adrian After Dark video format.
Love your videos, Adrian! Great detective work discovering that mouse-button disable feature for the RAM card. I got very similar jailbar video artefacts while trying to restore my old family IIsi - in 1-bit video mode I noticed the pattern of black bars repeated every 32 pixels (the data bus width of that machine). Looking at the jailbar pattern on your Sad Mac (a 32x32 icon centered on a 512 pixel wide frame buffer), if you count down from 15 starting from on the left side of the icon, you'll find the bar coincides with bit 10 where the first black bar on the left appears. This technique helped me home in on a capacitor-eaten data trace between RAM and the video IC on my machine.
simply amazing! great work!
Adrian you amaze me and your detective work is great. I like the after dark sessions. I look forward to your videos on Wednesday’s and Saturday
Great series!
This was satisfying to watch! Glory!
Truly excellent piece of diagnosis
Great job Adrian! It seems like a weird design choice that holding down the mouse button doesn't make it use the mobo RAM, but rather the first bank on the card.
Great videos, part 1 and 2 👍
I like After Dark, and I love the old screensaver too.
One of the best episodes to date! I always admire IPL or boot sequences for different platforms.
I wish someone explained the power-on procedure for later macbooks, like the pro from fall 2009.
that was a fun adventure! enjoyed it quite a bit.
awesome analysis
Nice hunt! Good job!
Hi, another great work! Recently i learned some ram debugging trick: wire method. One end of wire connected to gnd or 5v, and with other end you can pull down or up data lines of ram chips (for short time, not to damage chip) and look for vertical line
Yup, I was going to say this. To be safe you probably want to use something like a 10 ohm resistor instead of a wire, then if you short the power rails you shouldn't fry anything.
This Episode of After Dark is so spicy it needs an Only Adrian account. 🤪
Seriously though, I really enjoyed the way you backed off and walked us through the thought process to understanding how this particular RAM card design played with the motherboard and the errors you saw. Well done!
instant thumbs up for amazing work
Great video, Adrian! I like the after dark theme. What really caught my eye was the video ports on the SE in the beginning. I have a SE with similar ports, it has a video card made by Orchid Technology. I have never gotten the card to work. Either I’m missing a driver or the card is bad.
Ok, figuring that out about the mouse button really makes you look like a friggen genius, Adrian.
I have to say that going to Adrian's class is quite entertaining. I learned a lot.
Very good episode, Adrian. Hope you weren't _too_ wired at stupid-o'clock in the morning when you'd completed the repair and were able to get a good sleep after that :)
Certainly an intriguing fault given the unknown RAM boards and patina of limescale on the motherboard.
I would've thought removing the ram expansion and restoring the motherboard to stock would've been one of the first troubleshooting steps. After documenting how the expansion was set up, of course.
Just notice yours t-shirt ... May the 4th be with You. 😎 .... the force is strong with this One.
Keep the faith. You do what they all said couldn't be done. Board level repair. Those fatalists. We can't let them win.
Thanks for the content.
Keep up the good work.
בס'ד
RAM pulling: who else was reminded of 2001 Space Odyssey? „I’m afraid, Adrian. Adrian, my mind is going. I can feel it...' 😂
This whole troubleshoot reminds me of the "which cup has the Iocain poison" logic loop from the Princess Bride. "Parallel Pirates from Alameda don't like corrosion and will keep it as far as possible from them, therefore, I clearly cannot trust the RAM chip in front of me..."
I really love the 'after dark' vibe. I also enjoyed watching the chess game at the end.
This episode really catched and holded my attention from start to end.and i rarely watch 2nd chan videos. 👌
Vinegar would also work to remove those hard water stands and neutralize any remaining battery juice.
I had a few SE models myself. Never had a battery explode. I reallyi enjoyed this video. I no long have any MAC systems :(
Rammy approves of your ram troubleshooting skills Adrian.
Great interesting video well done you did a great job, these skills are being lost so i appreciate the efforts.
I’m really enjoying the after dark series. Definitely want more!
That was quite the journey 😊
Love the after dark content!
This was the fastest moving video you have made. Adrian, how much caffeine to stay up to do this? Fun all the same. Great deductions.
Amazing content.
Long but fun. Nice
Next time, Adrian takes apart that SE case and we see what's INSIDE !
Hell yess I love repair videos. No mather what you repair. Even if it ain't a computer at all.
Do you have a program that can now test all of the other ram on the expansion board, other than that first bank that we know works?
PS: I loved the entire deep dive and technical knowledge you have now bestowed on the world. I was following right along with you, talking to the screen about the different data lines and then you would mentioned them. So cool to see someone tear into these old PCs with your experience level. Thank you!
The twists and turns!
After watching this video I seem to remember doing the mouse button trick back in HS in the 90s on a Mac Classic that was acting up in class. Doing that made the machine slow but eliminated the crashes. A teenage me (who was only into PCs at the time) didn't bother to wonder why it worked, just that it did.
Think it's time to create a test kit for mac's... that was a good job figuring out what was going on....
“Zero to Sad Mac” sounds like progress to me 😅
That’s pretty impressive sleuthing to track down that mouse button trick.
So the old adage - don't assume - was true again! Well researched and solved!
18:50 "Happy Mac" more like "Hanging In There Mac"
I sent you a e-mail on a source for the DB-19 Right Angle Female that is new. Great Video!
Thanks for another great video. It really blows my mind how you managed to solved this. I'm really impressed by that!
Thanks!
You fixed it! What a ride 😁
I LOVE the after dark series!!
Great Job! Really enjoyed this video.
What a clever way to find the bad RAM chip.
Growing up with serial and USB mice, I always thought of them as something complex for later in the boot process when you'd gotten things running. It never occurred to me that the mouse button on its own might wind up as a TTL signal on the motherboard, but in retrospect given it was a huge part of the Mac, it's a pretty sensible way to do it.