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 collected 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 is maintained by Tomáš Slavotínek.
Last update: 20 Jan 2024 - Changelog | About | Legal & Contact