Maintenance 
DISASSEMBLY  PROCEDURE 
13. 
Remove the  two screws fastened to the  transformer 
bracket, then  remove the  bracket. 
. 
14. 
Remove the  Main  Shield  as follows (Figure  6-6k): 
a.  Remove the screw that fastens the Main Shield to 
the  Main  PCA. 
b. 
Grasp the Main Shield supports on one side of the 
instrument and pull the supports toward the center 
of  the chassis, bowing the Main Shield. Remove 
the  main  shield. 
15. 
Release the six plastic latches that hold the Main PCA 
. 
> 
to the chassis by pulling the latches upward (Figure 
.J 
*". 
1 
6-61). 
16. 
Lift 
the  front  end of  the Main PCA upward about 
3 
inches. 
17.  Free  the  white  lead  from  the  2A  INPUT  tower  as 
follows  (Figure 6-6m): 
a.  Guide the wire,  spring  and  fuse  contact  toward 
the  front  panel. 
b.  Thread  the  spring  and  fuse  contact  through the 
hole  in  the  front  end  of  the  tower. 
18. 
Slide the Main  PCA  forwards until  it  is free of the 
chassis. 
6-32. 
Front Panel Disassembly 
1. 
Holding the  chassis vertically  (with  the  front  panel 
downward),  remove  the  mounting  screws  from  the 
four  comers  of  the  Display  PCA  (Figure  6-7A). 
2. 
Holding  the  chassis  vertically  (now  standing  the 
instrument on the rear panel), pull the front panel off 
the  chassis  and set  it  aside (Figure 
6-7B). 
3. 
Remove  the  the  display  assembly  (Display  PCA, 
spacer matrix, and keypad) from the chassis 
as 
follows 
(see  Figure  6-7C): 
a.  Release the two plastic tabs on the front of  the 
chassis. 
b. 
Let  the  bottom  edge  of  the  display  assembly 
swing toward  the  rear  of  the  instrument. 
c. 
Pull the  Display  PCA toward the 
bottom of  the 
chassis. 
4. 
Separate the spacer matrix from the Display PCA 
by 
releasing the two pairs of plastic snap tabs on the back 
of  the  Display  PCA  (Figure  6-7D). 
5. 
Remove  the  keypad  from  the  spacer matrix. 
CAUTION 
The vacuum fluorescent display should 
not be  removed from the Display 
PCA; 
these  are  supplied  as one  part. 
6. 
Remove the  display window  from the front  panel 
as 
follows: 
a.  Slide the window upward (away from the buttons) 
about 
1132 
inch (Figure 
6-8A). 
b.  Push the window directly outward 
from 
the front 
panel  (Figure 
6-8B). 
6-33. 
REASSEMBLY PROCEDURE 
To reassemble the  instrument,  proceed 
as 
follows: 
1. 
Assemble the  front panel  assembly by  reversing the 
front panel disassembly procedure (Figure 6-7). (It is 
easiest to lay the keypad on the Display PCA before 
installing the  spacer  matrix  on  the  Display  PCA.) 
CAUTION 
The four  Display PCA mounting screws 
are self-tapping. To avoid damaging the 
threads,  ensure the  screws  are 
threaded properly before tightening. 
Do 
not  overtighten them. 
2.  Turn  the  chassis  upside  down. 
3. 
Install  the  Main  PCA  through  the  bottom  of  the 
chassis as  follows: 
NOTE 
When installing the Main 
PCA, 
guide 
the rear 
ribbon  cable  around  the  shield  connected  to 
the rear 
panel 
so  that  the cable 
is 
next  to the 
side of  the chassis. Make  certain that the cable 
is 
not 
pinched  between the shield and  the Main 
PCA. 
a. 
Slide the Main  PCA toward  the  rear  panel,  and 
position  the  power  connector  and  fuse  to  fit 
through their respective openings in the rear 
pan- 
el. 
b. 
Reinstall the white lead in the 2A  INPUT tower 
and  reinstall the 
2A 
fuse  in  the  front  panel. 
c. 
Make  sure  the  six  plastic  latch  heads  are 
extended. Lower the Main PCA into position on 
the chassis and guide the six plastic  latches into 
the circuit board supports on the chassis. Press the 
latch 
heads 
to lock the board in the chassis. Refer 
to  Figure  6-6L. 
4. 
Install one side of  the Main Shield; bow  it  to install 
the the other side, and secure it to the Main PCA with 
the retaining screw. 
5. 
Place the transformer bracket back  into position and 
fasten  down  with  the two screws. 
6. 
Replace  the  push  rod  for  the  POWER  switch  as 
follows: 
a. 
Insert the button end of the push rod into the 
rear 
of  the  front  panel. 
b. 
While supporting the opposite side of  the plunger 
with your finger, snap the other end of  the push 
rod  onto  the  POWER  switch plunger.  Refer  to 
Figure  6-65. 
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com