Macintosh IIsi Restoration

[PotatoFi]

@flaurencelle I have not! Techknight recommended checking out the corrosion on my board, especially around 245. I was thinking that I could flux up all of the legs and flow fresh solder, and try things again. I just haven't had a chance to revisit the project.

 

[Garrett B]

I loved reading through your restoration journey, and seeing all the attention to detail! I do hope you solve the issue with the white display.

I am working on a IIsi as well, and am in the process of replacing caps. For the PSU, it looks like you used a 33uf 35V radial in place of the 56uF 35V cap on Bruce's guide? I only ask because my unit had a 47uF 50V cap in that spot. I doubt someone went in and swapped it before I got in, but I wanted to verify that yours had a different value too. Not sure how much +/-15uF makes a difference!

 

[flaurencelle]

@flaurencelle I have not! Techknight recommended checking out the corrosion on my board, especially around 245. I was thinking that I could flux up all of the legs and flow fresh solder, and try things again. I just haven't had a chance to revisit the project.

I had corrosion there too, which i fixed, so i'm scratching my head ...! Which we had more schematics available to help us! I Measured 4V at C5, which seems a bit odd, but again, there was no op-amps on the schematics so hard to troubleshoot... Thanks for getting back to me! If you ever find the solution, let me know, and I'll do the same if I find something!

 

[flaurencelle]

I loved reading through your restoration journey, and seeing all the attention to detail! I do hope you solve the issue with the white display.

I am working on a IIsi as well, and am in the process of replacing caps. For the PSU, it looks like you used a 33uf 35V radial in place of the 56uF 35V cap on Bruce's guide? I only ask because my unit had a 47uF 50V cap in that spot. I doubt someone went in and swapped it before I got in, but I wanted to verify that yours had a different value too. Not sure how much +/-15uF makes a difference!

Hi Garrett, sorry for overlapping your post! Maybe there was different iterations of the power supply. If the capacitor is part of an RC network, then the value might be important. I recapped mine but I didn't even look at the values of the old ones i removed lol!