Before I put everything back together, I cleaned the Analog Board shield. I forgot to get a "clean" photo of it, sorry about that! But rest assured that it is very clean now.
All that's left is the Logic Board.
Since the battery blew up, the original battery holder was absolutely toast. Luckily, it didn't seem to do much damage around it! The orange stuff that you see I believe is some kind of adhesive, not fallout from the battery. But the through-holes for the battery were a total mess.
To burn through all of the corrosion, I used a bunch of liquid flux, a ton of heat (750°F on the iron), and repetition to clean out the holes. I would flux, heat, solder, desolder wick. I did that 3 or 4 times when finally, the corrosion and rust was all burned out, and I could see through the hole.
But then, disaster! When I pushed the battery holder through, soldered it, and then reheated the joint to full seat the battery holder, the pad popped right off! I had to abuse it pretty hard to get solder to flow, so while I was disappointed, I wasn't surprised.
Fortunately, the adjacent terminal is electrically connected. So I just bent the leg over and soldered it down to that. Not pretty, but it will work.
Board is done! I'm not going to install a PRAM battery, because it isn't needed to boot this machine, and due to the pandemic, I'm not sure when I can deliver this machine back to my friend, and I do not want to ship it. Sadly, it will most likely sit in my garage for a few months.
Does it work? Here's what it did with a floppy disk boot!
But there are three issues that I need to sort out:
1. The floppy drive squeaks! It's absolutely the drive motor or mechanism. It changes speed constantly. Very weird. It didn't do this before. The drive does read and write, though.
2. It won't boot from the hard drive, which is no surprise. But what is surprising is the sound! Check it out!
3. There's no beep when the system is first powered on. Perhaps the sound is damaged on the logic board?
I could use a bit of help on these so if you have ideas, please let me know. Especially about the sound.
This restoration is getting SUPER close to being done. At this point in time, I had three compact Macs torn apart at once, so I decided to put a few things back together to reduce the chaos a bit.
First, I hot glued the speaker back into the front of the case. I just do a dab of hot blue where the plastic posts were. The trick is to push the glue down into the holes a bit to hold it into place.
CRT reinstalled, chassis installed.
Floppy/hard drive bracket installed. No more rusty chassis!
Next, it was time to do a light recap on the analog board. To be honest, I only see one cap that is even remotely suspect... but I wanted to get this done now while I have it apart. I've created a cart on DigiKey with all of the caps needed for the analog board, sans the power supply (which I have yet to have trouble with on an SE).
Most likely due to the current pandemic, a couple of the caps weren't available, and I couldn't find a suitable replacement. I marked all of the caps with a green Sharpie before desoldering anything, so it be clear for the next person (or me) if and when the un-replaced caps fail.
Usually, this is where I post a shopping cart link, so you don't have to dig for capacitors. I'll update this post with a link soon.
I did the caps in small groups at a time to avoid desoldering a cap that I couldn't replace. Whenever I spec caps, I always find something that is the same capacitance, and the same leg spacing so it fits nicely. I will also substitute a higher-voltage cap in many cases.
Here's a random photo of a capacitor getting soldered in. Sometimes, I'll solder one leg, apply pressure from the top of the cap, and reheat the solder to seat the cap firmly against the board.
This one was a huge pain due to the hot glue. I was worried that I'd broken the component next door but it ended up being fine.
I wrote a quick note on the board explaining the green marks.
Here's one of the caps I couldn't replace:
Pile of old caps. I was a bit tempted to save these but... nah.
I think that's a much better way to do it. Trying to squeeze in plyers (needlenose or otherwise) would make it easy to scratch the coating on the CRT. I've never met an anode cap that didn't come off very easily - what I do is lift up the sides to see what direction the prongs are facing. I then hold the back of the anode cap and shift it to one side to compress the prongs and release one side and then tilt to get the one side out then you can just slide it off. No fuss and no tools.
I recently picked up a G4 Mac Mini (1.42 GHz) model, with MorphOS installed on the hard drive. Since I wanted to try running the Mac Mini 9.2.2 v9 from macos9lives, I cleaned it up, removed the drive and formatted it on another Mac and finally burned the CD with the modified OS 9.
However, everything went downhill from there - after putting everything together, the Mac Mini stays on the gray screen for around 3 minutes, and them immediately starts flashing the question mark folder - it doesn't even attempt to boot the CD. What's worse, I also found out that the USB keyboard and mouse doesn't work, so I can't even eject the CD, zap the PRAM, or boot into open firmware (when I ran the previous installation of MorphOS, the mouse and keyboard worked just fine, so no idea what happened there).
Any idea how to salvage this one? Will an official USB Mac keyboard and mouse from the era solve the issue?
Thanks for the tip on the logic board molex connector. However, I normally have the computer set normally when I reinstall the logic board, so I can't really put my hand below the logic board.
As for the anode cap, I always thought you could simply squeeze the fingers holding it in place from the outside. Guess I was wrong, though.
Tried powering up the Classic today and it was acting up again. I was able to get it to a flashing question mark icon ... hard drive doesn't seem to spin up. (I'm assuming it isn't getting the proper voltage.) On a couple of tries the machine chimed multiple times, one try it chimed probably 5-6 times. Also noticed the pattern slowly goes away. Unlike last night, I couldn't get it past the flashing question mark icon.
Guess I'm going to have to have the analog board recapped. I knew it was just a matter of time though... I've heard that the Classic/Classic II are notorious for having bad caps, although any old computer isn't immune.
I have a video of the behavior, but it's shaky.