Macintosh LC schematic

[amedeo_68k]

Hello, I'm looking for Macintosh LC logic board schematic, not LC II / III / 475. Does anyone have it ? Thank you

 

[joshc]

LC should be very similar to LC II. @max1zzz might have something as he reverse engineered these.

 

[amedeo_68k]

yeah, it is similar but the components enumeration is totally different

 

[max1zzz]

MacLC-Reloaded/LC_Schematics-V1.1A.pdf at main · max234252/MacLC-Reloaded

1:1 Reproduction of the Macintosh LC PCB. Contribute to max234252/MacLC-Reloaded development by creating an account on GitHub.

github.com

There are a few errors in that I need to fix, most notably i'm pretty sure the pins on the serial ports are connected in the wrong order but other than that it's should be 99.9% correct

there are also scans of the PCB an my traceing in sprint which may be useful for troubleshooting here: https://github.com/max234252/MacLC-Reloaded

 

[amedeo_68k]

Oh, thank you so much, so the +12V is required for audio to work (regulated to +8V)

 

[LetsgetStarted]

Old post I know..
Heads up..
Looks to me from inspecting an LC That capacitor C1 Positive(10UF 16V) connects to the UB10 Pin 5 directly... Not to R82 ,R83,C103..
This should be connected to UB10 Pin 5 and R83,C103 Please review!

 

[max1zzz]

Good spot! Positive on C10 should be connected to pin 6 on UB10 (along with R83 and C103) but not R82. I had it connected to the wrong side of R83/C103 (which connects to pin 5 and R82). Have corrected this

I will also say that the apple schematics are now floating around which should hopefully be error free

 

[LetsgetStarted]

Good spot! Positive on C10 should be connected to pin 6 on UB10 (along with R83 and C103) but not R82. I had it connected to the wrong side of R83/C103 (which connects to pin 5 and R82). Have corrected this

I will also say that the apple schematics are now floating around which should hopefully be error free

I went on git hub and marked it as an issue about pin 6 yes I made a mistake not pin 5 ... old eyes lol.. Just used the schematic to trouble shoot and thought I had an open wire ! Had me going for a bit!