Panasonic
Macintosh Classic, Classic II & Color Classic repair
Macintosh Classic, Classic II & Color Classic repair +External SCSI drive restoration Apple HD20SC
#Macintosh #Classic #Classic #Color #Classic #repair
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Be careful when manually turning the platters. You shouldn't rotate the platters backwards, because you can crash the heads and destroy the drive. If the heads have any tiny bit of resistance at all, you can rip them clean off turning the spindle by hand.
As for the ST-225N that doesn't spin, did you check for delayed start? Most SCSI drives have an option for delayed start, which keeps the spindle stopped until told to start by the SCSI host controller.
50 caps, including several large ones, to be replaced in the Color Classic's analog board… Apart from time consuming, that doesn't sound exactly cheap. How much is it for all of those?
21:55 that icon on the left, looking a little sus.
ah, the leg de-bending technique you use is not something i have thought of doing. that's such a good idea to reheat the solder to unbend the leg properly.
"Unfortunately it still works" 🤣🤣🤣
Whew! You crammed a lot into this video. I'm tired just from watching it!
An ultrasonic cleaner would make you jump for joy. In a couple of minutes it will clean out the grime and grease residue, leaving the part squeaky clean.
The Classic II needs to be adjusted, so the picture fills the screen. All that black makes my brain itchy.
Yeah Rodime drives were a thing back then. A friend and I bought two SCSI 105MB Rodime used drives (from the same local guy) for our Amiga 2000 machines. His drive lasted about 3 months then died. Mine was still working at that time so soon afterwards I sold it to a local guy as a working drive for some good money. I assume it died eventually but that wasn't my problem hehe!
Over-brightness could be a bad trimpot as they often get wear spots on them where there's no contact, meaning the value of the resistance is zero. Can also be caused by the flyback adjustment pots wandering over time (although they shouldn't wander). Or something in the brightness circuit on the board has failed.
For the Color Classic, you may try looking for broken solder joints around the flyback and the neckboard. If the grid pins are grounded or left floating intermittently, that would cause all sorts of weird behavior. Broken/corroded pots might be a problem too
We had a Classic II when I was growing up. It had a duck hunt clone, not sure if it came preinstalled or not, but when I’d enter my name for the high score “John Doe” was always on top. One day my parents were watching the news and the police were looking for some murder suspect in LA, and he was a “John Doe,” not knowing what that meant at the time I flipped shit thinking a murderer was in our house using my mac.
The Color's issues might not be caused by something else, but by several things, including the scorching diodes and bad caps.
One thing, I would check next is other diodes, maybe look at transistors… check for other excessively hot components, if you have a FLIR. Maybe replace thermo pads and grease underneath heat-sinks.
And overall, check whether there are loose legs or broken solder joints.
And maybe check the values of the poties, before switching on and after the fault appears.
Edit: early comment, I see now you did this on the 3rd drive.
Often these drives with stepper motors have stuck bearings in the steppers, the grease turns to glue after a while. The one that spins might just need a drop of bearing oil on the stepper bearings.
White lithium grease turns to concrete over time. Don’t use it!!
The fault on the Color Classic could be a faulty or dirty pot.
There is a solder bridge on the + leg of C9 on the mac classic
Positivity is contagious. Spread it! 🌈
I suspect that the glitches in the color mac are due to bad components on the neck board. Possibly a bad solder joint or MOSFET.
I would have thought that turning the hard drive motor against the normal direction would damage the drive heads. I'm just assuming they're always connected. Am I missing something? BTW, the Chemicon SM caps are not particularly exotic. They have many that are exceptionally good, starting with the fairly common KM series, if memory serves.
did you check scsi termination!
oh no, I was hopeful for the Trinitron! What about moving the drive trimmer back and forth a bit? Maybe it needs to be "cleaned". And you have a working miniscribe! Mine works but it's unusable…
I'll work on some Macs soon, I'll keep this video in mind!
Fwiw, the classics have system 6.0.3 in ROM. Use cmd R when powering on.
The still photo of the soldering iron 😂
sometimes on older drives, the main motor gets a bit stuck and is unable to spin up on its own. try applying power and immediately manually spin up the platter. this fixed an old prodrive 80s of mine.
Interesting technique for holding a hot soldering iron at 12:08!
I remember back in the day the C64 was completely silent except for the disk access. I believed that some day completely silent computers would be a thing. In spite of having 8 fans and a water pump, my computer is completely silent. So I was never fond of disks. And I was never fond of CRTs either. They were a bit flickery and I always thought they were a tad blurry. So I love the machines, but not the old media.
Thank you for straightening those capacitor legs 😉 So many times I didn't and regretted it hehehe
33:58 – There was a rare SCSI conversion upgrade option for the Hard Disk 20. Very few people got it, though.
Yay, Würth caps! My favorite. I like them because they tend to be the lowest cost amongst the higher performance capacitors (low ESR, temp, etc.) Way cheaper than similarly rated capacitors from Rubycon, Nichicon, and Chemicon.
i have a 250MB quantum harddisk and a working sony floppy drive but no computer for them
This episode took a bit of "elbow" & literal grease!