MaciNap User's Manual
Firmware v1.0
1. Overview
MaciNap is a small PCB designed for the SE and SE/30, which interrupts power to the analog board shortly after the video signal is blanked. It optionally reduces the speed of a PWM-enabled cooling fan to 50% or 75% while the screen is blanked. Shutting down the analog board when the display is idle can reduce power consumption by more than half and extends the life of the analog board and flyback transformer. An LED on the board indicates status.
2. Features
- Reduces heat, noise, wear on the CRT, power supply, analog board and flyback transformer.
- Reduces idle power consumption by up to 60%.
- Video blanking during wake-up prevents bright lines on CRT which can lead to burn-in.
- 50% and 75% fan PWM outputs reduce fan speed during sleep.
3. Specifications
- PCB Size: 43x16mm
- Maximum Current: 4A
4. Supported Models
- SE/30
- SE
- SE FDHD
- SE 1/20
- SE 1/40
5. Fan Notes
MaciNap can throttle PWM-enabled fans to 50% or 75% duty cycle, if the fan's PWM input is soldered to the PCB's "LOW" or "MED" pads respectively. Both 12V and 5V PWM fans are supported. Noctua supplies low noise adapters (LNA) with their fans. These are resistors placed inline with the power input (yellow wire). They reduce both the full speed of the fan, and the throttled 50%/75% speed of the fan during sleep mode. The fan must not be powered from the 12V sweep circuit or it will not operate in sleep mode.
6. Installation
- Remove AC power and case.
- Unplug power supply harness from the analog board.
- Identify the red wire in the harness (12V sweep power).
- The MaciNap PCB bridges a length of the red 12V sweep power wire. Choose a suitable location and orientation for the board and cut out a length of red wire similar to the length of the board. Do not cut too closely to either the power supply or the harness.
- Pass the included length of clear heat shrink tubing over the longer red wire. Once installed, this will protect the PCB and wiring from shorts. Also consider the routing of the video and fan PWM wires and pass them through the tubing if desired.
- If connecting a PWM-enabled fan, solder the PWM signal to either the "LOW" or "MED" pad. This wire is blue on Noctua fans. If you're unsure of whether to choose the "LOW" or "MED" signal, you can solder extra wires to both pads to maintain access to these signals after heat shrink tubing is applied.
- Choose which side of the PCB to pass the power wires through, note that the status LED is on the component side of the PCB.
- Strip the ends of the red wire and solder them to the large pads on the ends of the MaciNap PCB. "12V AB" connects to the analog board or harness side. "12V PSU" connects to the power supply side.
- Attach the twisted pair video input to the analog board. To minimize wire splicing, it is recommended to pass the video twisted pair through a hole in the analog board, remove excess length and solder the wires to the rear of the logic board harness connector.
- Inspect the connections, apply power and verify the normal function of the computer. Check that the amber status LED is constantly illuminated and video is active.
- Blank the screen using a screensaver and verify that the amber status LED changes to two repeating flashes. Sleep mode may also be verified using a Kill-A-Watt or similar power meter on the computer. Reduction in AC power draw is significant during sleep mode. If a PWM fan is connected, also check for a reduction in speed during sleep mode.
- When operation of the MaciNap PCB is verified, remove AC power from the machine
- Make sure no soldered joints have sharp points that may pierce the shrink tubing
- Pass the heat shrink tubing over the PCB, covering all connections and wires and carefully heat with a hot air tool, heat gun or hair dryer.
- Reinstall the computer's case
7. Indicators
MaciNap has a single amber LED which indicates three conditions:
- Bright - Video is active and the analog board is powered.
- Two flashes - Video signal is dark and analog board is shut down.
- Dim - CRT protect: analog board is starting with video signal suppressed.
8. Software
Any screensaver which completely blanks the screen will activate MaciNap's sleep mode.
Basic Black is a lightweight screensaver recommended for System 6 and 7.