35, 40, 56, 57, 76, and 77 - Power Supply

Models 35 / 56 / 76 Power
Models 40 / 57 / 77 Power

Planar Power Connectors (Pinouts)
   Planar Power Connector P1
   Planar Power Connector P2
Power Supply Voltages
Jump-starting the PSU


Planar Power Connectors (Pinouts)

Planar Power Connector P1 (5 V)

  Pin(s) Description
  1,2 +5 V DC
  3,4 GND

Planar Power Connector P2

  Pin(s) Description Notes
  1,2 +12 V DC
  3 Power Good +5 V if all voltages are stabilized
  4 Power ON/OFF OFF: +5 V, ON: Shorted to GND
  5 -12 V DC
  6 GND
  7 -5 V DC

Note: The P2 connector uses a non-standard wire colors - i.e. red for +12 V. Also the colors may differ from what's shown here in some cases - i.e. orange for +12 V.


Power Supply Voltages

If the power-on indicator is not on, check the power cord for proper installation and continuity.

  1. Check for continuity between pins 4 and 6 (switch) on P2.
  2. If the switch is OK, short pin 4 to pin 6 on P2 and check the power supply voltages.

Planar Power Connector P1 (5 V)

-Lead +Lead V Min V Max
4 1 +3.75 +6.25

Planar Power Connector P2

-Lead +Lead V dc Min V dc Max
6 1 +9.0 +15.0
6 5 -9.0 -15.0
6 7 -4.75 -5.5

Hard-drive Power Connector

-Lead +Lead V dc Min V dc Max
B A +9.0 +15.0
C D +3.75 +6.25


Jump-starting the PSU

Shut down the machine, unplug power cord from the PSU and open the case. Then unplug power-supply cables P1 and P2 from the planar and connect the power cord back to the unit. Short pins 6 and 4 on the power-supply connector P2 to start the unit.

The power-supply cooling fan must come up almost immediately - if you hear just a tiny clicking noise from the unit and power-supply is probably defective and has to be replaced. If the built-in fan comes up, check voltages. If all of them are within the given range the power-supply is functional, at least without load connected.

Content created and/or provided by:
Louis F. Ohland, Peter H. Wendt, David L. Beem, William R. Walsh, Tatsuo Sunagawa, Tomáš Slavotínek, Jim Shorney, Tim N. Clarke, Kevin Bowling, and many others.

Ardent Tool of Capitalism - MAD Edition! is maintained by Tomáš Slavotínek.
Last update: 29 Nov 2023 - Changelog | Legal Info & Contact