Bose ControlSpace ESP-88 Service Manual page 106

DC Power Supply +5V Adjustment Procedures
Astec Power Supply +5VDC Voltage Adjustment Procedure
CAUTION: Dangerous voltages are present when the
chassis is powered up and the top cover is off. Use care
when performing the below procedure.
Note: This procedure is to be performed on ESP-88C
and ESP-00 chassis using the Astec power supply only.
The Astec power supply uses a silver color cage. Refer
to the photo at right.
The Astec power supply is set to +5Vdc at the factory.
The ESP-88C and ESP-00 chassis require +5.2Vdc to
operate properly. Measure the DC voltage level using
the following procedure. Adjust the 5 volt level if needed.
1. Remove the chassis top cover. Check to see if the
chassis is using the original wiring harness. The original
wiring harness uses a translucent body connector at the
IPD Power Supply
DC power supply end. The upgraded harnesses use a
solid white connector. The examples shown at right are
for units with the IPD supply.
If the wiring harness connector has a translucent plastic
body, unplug it from the power supply and motherboard
®
and discard it. Install the upgraded harness Bose part
number 318935-001S.
Note: The wiring harnesses for the IPD and Astec
supplies are NOT interchangeable. They have different
wiring connections. Be sure to use the correct harness
for your chassis.
Remove the four screws located on the sides of the
power supply that secure the top half of the power
supply cage. Lift off the cage top.
2. With AC mains voltage applied, measure the +5Vdc
level at the DC output connector on the power supply.
Place the positive (+) probe on the red wire at the pin 2
location. Place the negative (-) probe on the black wire
at the pin 3 location.
3. If the DC voltage level reads less than +5.2Vdc,
adjust the +5 Volt potentiometer clockwise until the
meter reads +5.2Vdc.
4. Turn off AC mains to the chassis.
5. Re-assemble the power supply and replace the
chassis top cover.
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