IBM 2179, 6643 manual Display

Pin	Signal	Function
5	COM	Ground
6	5 V	+5 V dc
7	COM	Ground
8	POK	Power Good
9	5VSB	Standby Voltage
10	12 V	+12 V dc
11	3.3 V	+3.3 V dc
12	-12 V	-12 V dc
13	COM	Ground
14	PS-ON	DC Remote Enable
15	COM	Ground
16	COM	Ground
17	COM	Ground
18	-5 V	-5 V dc
19	5 V	+5 V dc
20	5 V	+5 V dc

If the voltages are not correct, and the power cord is good, replace the power supply.

Display

Note:

The number of defective pixels to qualify a TFT LCD panel to be replaced under warranty is 8 or more for all types 2179 and 6643 computers.

If the screen has no display (black screen), do the following:

1.Replace power supply.

2.Replace inverter card.

3.Reseat/replace receiver board (receiver board is behind the LCD display.

If the screen comes on, then, quickly goes black, do the following:

1.Check power supply fan. If fan is running:

a.Replace inverter board.

b.Replace receiver board.

2.If Power supply fan is not running, replace the power supply.

If the screen pallet color is wrong, do the following:

1.Replace LCD signal cable.

2.Replace receiver board.

3.Replace system board.

If there are scaling problems, do the following:

1.Assure latest level video drivers are installed.

Chapter 4. FRU replacements 17