Maintenance
Module 8023
6-16
SEARCH HEADBOARD REMOVAL & REFITTING
Located behind the removable end plate of your detector search head case is a
further electronics board. This board supplies the drive to the central transmitter
coil and initially processes the signals received from the two symmetrical
receiver coils.
Since every board is customised to suit the particular detector it is fitted into,
there are a variety of components that must be checked, and possibly swapped
between the old board and the new board. There are also two power rails that
will need to be checked and adjusted as required. If Loma has provided the
board for a specific serial numbered detector then some of these components
may already be correctly fitted.
This section serves as a guideline for replacement of the detector search
headboard. While working with the circuit board an antistatic wrist strap should
be worn.
The process described seeks only to cover the minimum requirements needed
to ensure a successful board replacement and does not cover the full set up
process. Once completed the detector will be functional, however if any fine
adjustment is required, which may be indicated by a slight loss in performance
then contact your local Group Service Centre to arrange a service call.
The components that must be checked to ensure a successful board
replacement are described in the
on page 18
. The board
is shown in
below
the mounting arrangement in
on page 17
with
the wiring connections in
on page 17
all in this section.
Figure 6 Search Headboard
Frequency
Selection Links
High frequency
Low frequency
L1 copper case
L1 fixed value
OSGO
Fixing holes
Tx output
Tx gnd
+ 12 volts
A gnd
- 12 volts
Ctrl 3
IC17
IC15
+Vo
-Vo
R51
Ctrl 4
Crystal
Ctrl 1
Ctrl 2
RF input
RF gnd
Balance
R
D
1
R
D
3
R
D
2
JP1
C23
C24
R35
R out
Sig gnd
X out
Metal Spacer
fits here
R44
R34
R41
9-10
11-12
7-8
5-6
3-4
1-2
1
I
2
3
I
4
5
I
6
not used
TP4
TP2
Summary of Contents for IQ2
Page 92: ...Maintenance Module 8023 6 1 Frequency links Tx Inductors Balance inductors ...
Page 101: ...Wiring Diagrams Module 10088 8 2 Figure 1 Optional External Sensor Connection Ladder Diagram ...
Page 102: ...Spare Parts Module 11050 9 1 SPARE PARTS CONTENTS Spare Parts Lists 2 ...
Page 104: ...Service Return Module 12005 8 1 SERVICE RETURNS FORMS CONTENTS Instructions 2 Form 3 ...
