Power Supply Voltages / Fans - IBM PS/2 95 XP 486 Hardware Maintenance Service

6.0 Power Supply Voltages / Fans

While shorting pins 1 and 2 together, read the voltages on the other pins.
If the voltages are incorrect, replace the power supply.
+------------------------------------------------------------------------+
¦ V dc ¦ V dc
¦ Minimum ¦ Maximum
+-----------------+------------------+-----------------+-----------------¦
¦ ¦
¦ +3.7 ¦ + 6.2
¦ +9.0 ¦ +15.0
¦ - 9.0 ¦ - 15.0
¦ +3.7 ¦ + 6.2
¦ +9.0 ¦ +15.0
¦ ¦
+------------------------------------------------------------------------+
PICTURE 2
In addition to the power supply fan, some systems require a fan on the
system access cover. Excess heat will cause intermittent failures.
the power supply fan failed, replace the power supply.
the system access cover fan failed, do the following:
1. Check for 12 V dc (±1.4 V dc) at the two fan cable assembly pins on
the system base.
If the voltage is correct, check for 1300 ohms (±10%) resistance
between the fan terminals.
If the resistance is incorrect, replace the fan.
If the resistance is correct, check the spring clip connections.
If the connections are good, there is not a fan problem.
2. If the voltage is incorrect, unplug the fan cable assembly from
connector J28 on the system board and check the cable assembly for
continuity (see the figure on page 12.0).
If the cable has continuity, replace the system board.
If the cable does not have continuity, replace it.
IBM PS/2 Model 95 XP 486 HMS
Power Supply Voltages / Fans
¦ -Lead ¦ +Lead
¦ Pin ¦
¦ ¦
¦ 5 ¦
¦ 5 ¦
¦ 5 ¦
¦ B ¦
¦ B ¦
¦ ¦
To determine if
¦ Copyright IBM Corp. 1990, 1991
6.0 - 1
¦
Pin ¦
¦
3 ¦
4 ¦
7 ¦
D ¦
A ¦
¦
If