Ram Boards - HP 340 Series Service Manual

Installing the LGB Board Just Removed
1. Reverse the three removal steps.
2. Replace in reverse order the items listed in the Preliminary Requirements.
Installing a New LGB Board
1. Remlove the two
#
1 Pozidri v screws in the backplate next to the LG B interface port on
the new board.
2. Remlove the two #1 Pozidriv screws holding the back plate to the LGB board.
3. Remove the backplate and install it on the board you removed from the SPU.
4. Install the new LGB board in the top slot.
5.
Replace in reverse order the items listed in the Preliminary Requirements.
RAM Boards
Preliminary Requirements
Turn OFF the SPU and remove these items in the order listed:
1.
Power cord.
2. Video and interface cables.
3.
Case.
lRemoval
On the processor board, each
RA~1
board connector is hard-wired for a specific 4 Mbyte block of
addresses. The left-hand connector (closest to the power supply) is RAM 1 and the right-hand
connector (next to the edge of the processor board) is RAM 4. RAM board positions and the
three most significant hexidecimal bits of the connector address is labled on the top of the SPU
backplane.
Table 2-3 lists each RAM board connector's number, top address three MSBs, and the top and
bottom addresses. Figure 2-8 will help identify them.
Table 2-3. RAM Board/Connector Numbers and Address Blocks
RAM Board Top Bottom
Connector /Label
Address Address
RAM l/FFF FFFFFFFF FFCOOOOO
RAM 2/FFB FFBFFFFF FF800000
RAM 3/FF7 FF7FFFFF FF400000
RAM 4/FF3 FF3FFFFF FFOOOOOO
Assembly Replacement
37