Uploaded September 2025 | Updated September 2026, 1 week ago
The Macintosh IIsi was launched as a lower-cost alternative in the Macintosh II series. To keep costs down, Apple used more electrolytic capacitors, and the surface-mount electrolytic capacitors from the early 90s are past their expected lifetime. In addition, despite the power supply being made by Sony, the capacitors in it are also known to leak (though I can't help think "cost tweaking" by Apple led Sony to use lower grade capacitors).
I did what I didn't want to do: I've spun the "Wheel of Regrets™", and I'm going to blame eBay's new "feature" that tells you if someone else has an item in their cart. All in the name of making a working IIsi. I've probably made a crummy deal, but maybe there will be spare parts to resell to recoup costs. At least the seller shipped promptly.
How many of this crummy Mac do I now own? Will any of them work? How crummy of a deal have I made? You'll have to watch to find out!
*
Table of Contents
0:00:00 Pre-Roll
0:02:39 Greetings and Announcements
0:05:07 Wheel of Regrets™ (Who comes up with these titles anyway?)
0:05:07 Wheel of Regrets™: IIT 4C87SLC-40 Math Coprocessor (for 386DX motherboards)
0:08:49 Wheel of Regrets™: "Macintosh IIsi Repair Bundle"
0:14:10 Physical Inspection of IIsi Number 3
0:21:25 Testing IIsi Number 3
0:29:00 Physical Inspection of IIsi Number 4
0:34:08 Testing IIsi Number 4
0:38:15 Back to Testing IIsi Number 3
0:57:05 Let's Remove the Capacitors from IIsi Number 4
1:31:40 Let's Try IIsi Number 3 Again While We Wait
1:34:30 Still in a Holding Pattern/Channel Announcements
1:51:16 Let's Recap IIsi Number 4
2:31:55 Testing Recapped IIsi Number 4
2:47:23 Closing Thoughts
2:54:14 Outro
*
Ways to Support the Channel:
☕️ Tips or Support via Ko-fi: ko-fi.com/jdmcs
🈷️ Support me on Patreon: patreon.com/jdmcs
📦 Amazon Wishlist: jdmcs.net/wishlist
... or simply do the YouTube things: Like/Dislike, Comment, Subscribe, Enable Notifications, and participate in the Chat. These things help the channel, too!
**
Read Computerized Start™, my Official Blog: jdmcs.net/myblog
Follow me on Instagram: jdmcs.net/myinstagram
Follow me on Twitter: jdmcs.net/mytwitter
The Macintosh IIsi was launched as a lower-cost alternative in the Macintosh II series. To keep costs down, Apple used more electrolytic capacitors, and the surface-mount electrolytic capacitors from the early 90s are past their expected lifetime. In addition, despite the power supply being made by Sony, the capacitors in it are also known to leak (though I can't help think "cost tweaking" by Apple led Sony to use lower grade capacitors).
I did what I didn't want to do: I've spun the "Wheel of Regrets™", and I'm going to blame eBay's new "feature" that tells you if someone else has an item in their cart. All in the name of making a working IIsi. I've probably made a crummy deal, but maybe there will be spare parts to resell to recoup costs. At least the seller shipped promptly.
How many of this crummy Mac do I now own? Will any of them work? How crummy of a deal have I made? You'll have to watch to find out!
*
Table of Contents
0:00:00 Pre-Roll
0:02:39 Greetings and Announcements
0:05:07 Wheel of Regrets™ (Who comes up with these titles anyway?)
0:05:07 Wheel of Regrets™: IIT 4C87SLC-40 Math Coprocessor (for 386DX motherboards)
0:08:49 Wheel of Regrets™: "Macintosh IIsi Repair Bundle"
0:14:10 Physical Inspection of IIsi Number 3
0:21:25 Testing IIsi Number 3
0:29:00 Physical Inspection of IIsi Number 4
0:34:08 Testing IIsi Number 4
0:38:15 Back to Testing IIsi Number 3
0:57:05 Let's Remove the Capacitors from IIsi Number 4
1:31:40 Let's Try IIsi Number 3 Again While We Wait
1:34:30 Still in a Holding Pattern/Channel Announcements
1:51:16 Let's Recap IIsi Number 4
2:31:55 Testing Recapped IIsi Number 4
2:47:23 Closing Thoughts
2:54:14 Outro
*
Ways to Support the Channel:
☕️ Tips or Support via Ko-fi: ko-fi.com/jdmcs
🈷️ Support me on Patreon: patreon.com/jdmcs
📦 Amazon Wishlist: jdmcs.net/wishlist
... or simply do the YouTube things: Like/Dislike, Comment, Subscribe, Enable Notifications, and participate in the Chat. These things help the channel, too!
**
Read Computerized Start™, my Official Blog: jdmcs.net/myblog
Follow me on Instagram: jdmcs.net/myinstagram
Follow me on Twitter: jdmcs.net/mytwitter
