HP A4500A - VMEbus Single Board Computer 744 Motherboard Hardware Manual page 189

DC-DC Converter Replacement
DC-DC Converter boards and one or two slave boards (depending on the CPU speed) are required to power
each CPU.
NOTE Each CPU requires a DC-DC Converter and slave(s) to operate. When CPUs are upgraded or
replaced, ensure that the accompanying DC-DC Converter and slave(s) are changed. When
returning replaced CPUs to Hewlett-Packard, ensure that the accompanying DC-DC Converter
and slave(s) are returned also.
The converter boards stand on edge in slots and are located immediately behind the Power Supply on the left
and right sides of the System Board, in front of the CPU assemblies.
DC-DC converter boards are not "hot-swap" or "hot-plug" units. Shut the server down and
CAUTION
unplug the electrical connection prior to removing or replacing DC-DC converter boards.
To replace a DC-DC Converter board and its slave(s) from the server, perform the following steps:
Step 1. Grasp the board by the left and right edges.
Step 2. Align the board connector with the slot. The slot and board are keyed so that the board will only fit
one way. Place your thumbs on the top edge of the board, near the left and right sides, and push the
board straight down into its slot until either an audible "click" is heard, or the levers close and seat
into the slots in the side edges of the board
DO NOT press hard on the left/right levers or they will break. Levers provide vertical stability,
CAUTION
only.
The following graphic shows a DC-DC converter board and slave(s).
Chapter
CPU MHz Master
440 1
550* 1
* When available
DC-DC Converter Replacement
Slave
1
2
273