So I picked up an LCIII for repair. The TDK PSU was toast - caps are good but the optocoupler is open-circuit and I'm awaiting a replacement. So I bodged into service a spare Astec Beige G3 PSU and the machine booted-up fine on its aged caps. I quickly recapped with tantalums (as you do) but...| TinkerDifferent
The Macintosh LC III is the (not surprisingly) third version of the LC computer introduced in October 1990. The original LC was part of a trio of low-cost Macintosh computers intended to challenge the growing dominance of PCs and also stand up against the Commodore Amiga and Atari ST. The low-cost trio included the Classic, the LC, and the IIsi. The Classic carried on the original Macintosh form factor, replacing the venerable Macintosh SE, and the Macintosh IIsi was a scaled-down Macintos...| Retro Viator
Hi, Am I the first person to discover this? C22 (the 47uF capacitor in the corner beside the power supply connector) on our LCIII has the + sign on the PCB on the negative capacitor terminal. This capacitor is between -5V and ground. The original C22 electrolytic on this board, and on...| 68kMLA
