(continued)

005(continued)

DID THE SYMPTOM CHANGE?

Yes No

006

Go to Step 008.

007

– Check the Media Console cable for continuity. See “Media Console Cable” on page 5-16 for pin locations.

Depending on service procedures, replace the keyboard, Media Console host card, Media Console client card, Media Console cable, or Media

Console.

– If the symptom remains, replace the system board.

008

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Power-off

the

system

unit.

 

 

 

– Disconnect the keyboard cable connector from

the

system

board (Type

2140)

or

from

the

Media Console (Type 2142).

 

 

Power-on

the

system

unit.

 

 

 

 

– Check

the

voltage

at

the

keyboard cable connector

on the system board

or the

Media

Console

as

shown in Figure 2-4,

after

the

POST.

Note: Measure voltages with respect to Ground (Pin 3). These

 

 

measurements are for the system board

(Type 2140) and for the

 

 

Media

Console

keyboard connector (Type

2142).

 

Pin

Voltage (Vdc)

 

 

1

KBD Data (+5.0)

2

Not Used

3

Ground

 

 

4

+5.0

 

 

5

Clock (+5.0)

 

 

6

Not Used

 

 

65

43

21

Figure 2-4. Keyboard Connector Voltage Check

(Step 008 continues)

2-40

Page 96
Image 96
IBM 2142, 2140 manual Did the Symptom CHANGE?, Post