Replacement Of Interface Module; Replacement Of If-Unit; Replacement Of Cpu-Board; Replacement Of Ps-Board - Hameg HM5014-2 Service Manual

5 . M o d u l e R e p l a c e m e n t
dule. Gently press the module into place. Connect the 3 wires
RIC10, RIC11 and WIC2. Take the HM5014-2 into operation (ref.
to paragraph. 5.18)

5.3 Replacement of interface module

Turn the instrument to the rear. See Fig. 5-2 for orientation,
the interface module is the small PCB with the 9 pin SUB-D
connector towards the back.
5.3.1 Removal of interface module
Remove the cable RiC12 from the connector and remove the
2 countersunk screws holding the interface in place. Remove
the interface.
5.3.2 Installing of interface module
Put the new interface module in place and fi x it with the 2 co-
untersunk screws. Connect RiC12. Take the HM5014-2 into
operation (ref. to paragraph. 5.18)

5.4 Replacement of IF-Unit

To exchange the IF-unit, it is not necessary to open any of the
covers. See Fig. 5-5 for orientation. Rotate the instrument for
convenient access.
RiC5
M1
M3
Figure 5-5: Location of screws of IF unit
5.4.1 Removal of IF-Unit
Remove the 4 holding screws (M1 – M4), one at each "corner"
of the IF-unit (see Fig. 5-5). When loose, carefully disconnect
all cables, RiC5 and CiC2. Remove the IF-unit, take care not to
damage the power switch rod. The unit is changed as a whole.
Do not loosen further screws.
5.4.2 Installing of IF-Unit
Take the new IF unit, and fi x the cables RiC5 and CiC2 before
putting it into place, take care not to damage the power switch
rod. Then use the 4 fi xing screws to hold it in place. Take the
HM5014-2 into operation (ref. to paragraph. 5.18)

5.5 Replacement of CPU-Board

The replacement of the CPU-board has several steps. See
Fig. 5-6 for orientation (First M1 – M7, then, after removing the
cables, loosen M8 – M11).
22
Subject to change without notice
M2
CiC2
M4
RiC4 RiC6
M1
M8
M3
M2
M4
M9
WiC4
Figure 5-6: Location of screws and cables of CPU unit
5.5.1 Removal of CPU-Board
To remove the CPU-board, fi rst loosen the 7 countersunk
screws holding the cover. These are indicated in Fig.
remove the cover.
Now loosen all of the connecions to the CPU-board, RiC4,
RiC6, RiC9, CiC7, CiC8, RiC12, RiC11, WiC4, WiC3, CiC4 and
CiC5. Especially the 4 coaxial cables should be marked in or-
der not to put them in a wrong place when assembling again.
Now loosen the 4 screws holding the CPU-board in place and
remove the board.
5.5.2 Installing of CPU-Board
Set the new CPU-board into place and fasten it with the 4
screws to the chassis. Replace RiC4, RiC6, RiC9, CiC7, CiC8,
RiC12, RiC11, WiC4, WiC3, CiC4 and CiC 5. Put the cover on the
CPU-board and fi x it with the 7 countersunk screws. Take the
HM5014-2 into operation (ref. to paragraph. 5.18).

5.6 Replacement of PS-Board

Turn the instrument to the rear. Before removing the cover of
the PS module, make sure that no power is connected to the
HM5014-2. See Fig. 5-7 for orientation. Note the countersunk
screw holding one part of the interface module.
M3
Figure 5-7: Location of screws of PS unit
5.6.1 Removal of PS-Board
To remove the PS module, loosen cables WiC2, WiC4 and
RiC10. Then unsolder the Earth connection next to the power
switch (see Fig. 5-7). Remove the power switch rod by gently
RiC9 RiC5
M6
M10
M5
M7
M11
RiC12
5-6. Then
M2
M1 WiC2
M4 RiC10