2500 SX/20  (250-4077)             Settings             Faxback Doc. # 1103

Note: Refer to Faxback Doc. # 1194 for Board Layout.


Note: A jumper is a cover that contains metal contacts.. The jumpers in 
this section are shown for reference They do not have to be changed in most
cases.  Default (factory) jumper settings are listed in "Configuration
Settings."  To install a jumper, place it over two adjacent pins to connect 
or bypass a circuit. A jumper can be installed, parked, or removed.

Function              Description                 Settings

Video Interrupt:      Standard *                  E14 and E15--no connection
                      IRQ9                        E14 and E15--installed
On-Board Video:       Enabled*                    E11 and E12--installed
                      Disabled                    E12 and E13--installed
Audio Input:          Microphone*                 E24 and E25--installed
Source:               Line-Level                  E25 and E26--installed
Audio Output:         Headphone*                  E28 and E29--installed
Source:               Line-Level                  E20 and E30--installed
Monitor Type:         VGA analog monitor or       E19 and E20--installed
                      standard multiple-
                      frequency monitor*
                      Non-standard multiple-      E20 and E21--installed
                      frequency monitor
VGA BIOS:             PS/2 mode*                  E17 and E18--installed
                      AT mode                     E16 and E17--installed
IDE (SmartDrive)      Disable*                    E22 and E23-no connection
Activity Indicator:   Enable                      E22 and E23-installed

* Indicates default (factory) setting.

Installing Audio Jumpers:

The Music and Sound features enable you to connect a microphone, an 
earphone, or a stereo headphone. To connect a line-level audio device such 
as a radio or a tape recorder, you must adjust the two audio jumpers on the 
main logic board. With the jumpers in the line audio position, you can 
connect line-level devices to the microphone (input) and headphone (output)
connectors. Refer to "Main Logic Board Layout" to locate the Audio Input 
Source and the Audio Output Source jumpers. Read the following sections 
before connecting line-level audio devices.

Audio Input Source Jumper:

The Audio Input Source jumper pins are labeled E24, E25, and E26. The jumper
installed on these pins enables you to direct sounds from audio devices 
through the computer. For example, you can connect a microphone to the MIC
connector to input your voice.

By default, the Audio Input Source jumpers is installed on Pins E24 and E25 to 
enable the connection of a microphone. Install the jumper on Pins E25 and 
E26 to enable the connection of a line-level audio input device (and disable 
the connection of a microphone).

               ┌─────┐
               │     │                    X    E24
               │  X  │ E24             ┌─────┐
               │     │                 │     │
               │  X  │ E25             │  X  │ E25
               └─────┘                 │     │
                                       │  X  │ E26
                  X    E26             └─────┘
            Microphone Position     Line-Level Audio
             (Default)               Input Position

Audio Output Source Jumper:

The Audio Output Source Jumper pins are labeled E28, E29, and E30. The 
jumper on these pins enables you to direct sounds from the computer to an 
audio device. For example, you can connect a stereo headphone to the EAR
connector on the computer. Sounds from the computer are sent through the
headphone so that only you can hear them. When no device is plugged into the 
EAR connector, sound is sent through the built-in speaker, If you are using 
the built-in speaker, the Audio Output Source jumper can be installed in 
either position.

By default, the Audio Output Source jumper is installed on Pins E28 and E29,
enabling the connection of an earphone or a headphone. Install the jumper 
on Pins E29 and E30 to enable the connection of a line-level audio output 
device (and disable the connection of an earphone or a headphone).

              ┌──────┐
              │  X   │ E28                X     E28
              │      │                 ┌──────┐
              │  X   │ E29             │      │
              └──────┘                 │  X   │ E29
                                       │      │
                 X     E30             │  X   │ E30
                                       └──────┘
         Headphone Position           Line-Level Audio
         (Default)                    Output Position

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