• Hello MLAers! We've re-enabled auto-approval for accounts. If you are still waiting on account approval, please check this thread for more information.

Search results

  1. P

    Macintosh Plus International Analog Board CR15, CR17 and CR18 Zener Diodes

    Hi! My analog board is having dificulties reaching the 5V DC output. At the maximum the potentiometer only gives ~4.90V Dc and never triggers the crowbar circuit. The Logic Board has 4MB RAM upgrade and boots up altough the under voltage at 5V. On the Macintosh Repair and Upgrade Secrets book...
  2. P

    Macintosh Plus Analog Board Optocoupler

    Hi! I'm troubleshooting my Macintosh Plus power supply and I suspect that I have a bad optocoupler. My analog board is the international version 220V. The original optocoupler is the GE H11AVX515R which I can't seem to find online. I have a substitute optocoupler from Motorola (4N35) that I...
  3. P

    Macintosh Plus - Trouble after doing SCSI Term Diode Mod

    Hi! Continuing my Macintosh Plus 4Mb total restore, I bough a BlueSCSI2 external module and installed a number of disk images. It was working like a charm. Then, I went to the CR1 diode mod, so that I could have TERM power on the SCSI port to avoid the need to power the BlueSCSI2 from a usb...
  4. P

    Recapped Analog Board Macintosh Plus Stuck at the First Screen

    Hi, I recapped my Macintosh Plus analog board with the Console% kit. When it turns on, the voltages at the FDD port are -12,14V +12,10 V and 5,01 V. There are no strange noises or hissing. It's completely silent. I don't get the turn on chime, neither the FDD seeks or rotates, although it has...
Back
Top