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Gorilla 5 minute epoxy clear. I can't find a product number, though. https://amzn.to/4ad4YlZ

Yes. That's it.

A while back, I picked up a loose Macintosh II motherboard for the sole reason that it contained the rare (not valuable, but rare) recalled Macintosh II ROMs. These ROMs contain a bug that prevents NuBus cards from accessing more than 1 MB of NuBus space. However, the board itself was trash...

I am seriously considering replacing the serial diagnostic in the ROM with something better suited for the problems we encounter. I would just patch the start of the existing code to jump to the end of ROM (where I assume there is plenty of free space). This would be particularly useful for the...

Wow! Thank you very much. You've made my day.

The other day, I posted about repairing some Macintosh II motherboards. https://tinkerdifferent.com/threads/macintosh-ii-advanced-diagnostic-techniques.5020/ Two of the 'dead' motherboards had bad 31.3344 MHz oscillators. I thought it would be interesting to open up the oscillators and try to...

I was unaware of that. Thanks for taking the time to explain.

Here is a better look at the Portable battery input connector (J17) on the motherboard. Like other power connectors (such as on the Macintosh II, IIcx, or LC series), the ground inputs are actually connected together on the PCB itself. However, unlike other power connectors, the +V inputs are...

Also, is this needed for both the backlit and non-backlit?

Really? I could just throw the tst instruction into the Quiet Portable init if that's all it is. So, does that completely eliminate the slowdown when using 7MB of memory, or just the additional penalty after waking from sleep?

Given the difficulty of finding non-surface-mount parts, I got the impression this was just a hobbyist exercise, rather than commercial or a replacement. Maybe I misunderstood the purpose of this project. I agree that it isn't fair to distribute copies of Steve's proprietary IP. However, I also...

The Macintosh II computer motherboard revision 820-0228-A is the most common. Unfortunately, it is the most corroded due to using many more surface-mount electrolytic capacitors. Nearly all of the repair work is located around these leaky capacitors. The techniques described in this post are...

I regret reusing an old hard drive cable for this photo -- as the color of the wires is confusing when used on a Portable. Give me a minute and I'll upload a better diagram.

I am so glad you said that, because that's what I had to do to get the Portable to not crash when playing sounds. I was embarrassed to post my 'hack' because I felt it wasn't a solution. But, given how many Portables you've worked on, and given that Apple disabled this in the backlit model, it...

Do you have an oscilloscope? I would measure this point in the circuit and see if the amplitude declines. You might be able to catch this with a voltmeter in peak measurement mode which you reset between playing a sound. Basically, if the voltage levels declines (when you play the beep sound in...

If you want to further narrow down the location of the sound issues, put some headphones on or use an external speaker. If the problem persists, it exists prior to that portion of the sound circuit.

Well, it was a team effort. You were passionate about getting the issue attention to be fixed, and @SuperSVGA found and analyzed the faulty code. The more I use the Portable, the more I fall in love with it. It has a really smooth keyboard and crisp screen. Now we just need to get the SLIMs...

Very nice!

Based on the work of @SuperSVGA and @JDW, I created a system extension that quiets the 10 second popping. You can use this with either the backlit or non-backlit Portable, on any system version that the Portable supports, with any version of the Portable control panel. Use StuffIt, BinHex, or...

Ahh! That answers that question. Thank you.