Mac Classic US Version 630-0395 Recap

[YMAC]

I recapped this classic board, it was just flupping when powered on when I got it. After the recap it had the checkerboard with wavy pinched video. The 12V rail was 11.1V but it would slowly rise until it was high enough to power on properly. I ran the board through the dishwasher and dried it thoroughly. After that it now works perfectly. I had cleaned under the leaky caps really well with alcohol but that was not enough. Before the cleaning I pulled a bunch of components and tested them, all of the diodes that I pulled around the caps tested good. I read that the voltage control circuits on these were sensitive but I was pleasantly surprised when cleaning it fixed all of my issues.

I did recap the logic board at the same time, but that was not very interesting.

Since @Branchus only has the 220V version on his Recap-A-Mac site I am putting the cap layout for the 630-0395 board that I have here. Feel free to use the image on your site and re-create my super quick values image to make it look good and match the site. Thanks for that resource, I have used it many times.

 

[Garrett]

For what it's worth, there seem to be a couple US versions of this board. The one I see most commonly has a 470uF 50V cap in place of the 1000uF 35V one you have at CP2. I am guessing your board is an early revision. I am not sure if the value matters and either cap may be used in that position, but I feel that it's always best to use what was originally installed. Either way, great job creating this diagram. The first recap schematic of this rev. board that I've seen!

 

[YMAC]

I did not find a lot of good info on these boards so I figured I would share here. I am fairly sure the original was the 1000µf, it did not look like this had been worked on.

I got it from someone that had it stored in their basement for the last 20ish years. The manufacture date is Feb 1991.