IBM 6643, 2179 manual Installing a DIMM, Power Supply, pin main power supply connection

Installing a DIMM

Notches

1.Position the DIMM above the connector so that the two notches on the bottom edge of the module align properly with the empty connector.

2.Firmly push the module straight down into the connector until the retaining clips pop up and fit snugly around both ends of the module.

Power Supply

If the power-on indicator is not on, the power-supply fan is not running, or the computer will not power-off, do the following:

Check/Verify		FRU/Action
Check the following for proper installation.		Reseat
v	Power Cord
v	On/Off Switch connector
v	System Board Power Supply connectors
v	microprocessor(s) connection
Check the power cord for proper continuity.		Power Cord
Check the power-on switch for continuity		Power-on Switch
when pressed.

If the above are correct, check the following voltages.

20-pin main power supply connection

See “System board layout” on page 14.

Attention:

These voltages must be checked with the power supply cables connected to the system board.

Pin	Signal	Function
1	3.3 V	+3.3 V dc
2	3.3 V	+3.3 V dc
3	COM	Ground
4	5 V	+5 V dc

16Hardware Maintenance Manual