Sharp PC-1285 Service Man page 6

8-10. Display test
Items required for display check:
• PC-1280 (for program entry)
• Half-size RAM card (for test)
• PC-1285 to be tested
The contents of both PC-1280 and the RAM card will be lost during
the test.
(1) Set the RAM card in the PC-1280 and do ALL RESET.
(2) Enter SETMEM"1"
[:;;D .
8-9. Display side cabinet and keyboard side
cabinet
These two cabinets are held together with a spring pin. To replace
either one only, it
may
be possible to scrape the cabinet with the cut-
ter and to remove the spring pin with a pair of pliers, but the pin, once
pulled out, cannot be re-used.
Length
PWB unit
J1 140 MainPWB
J2 105
J3 127 Memory PWB
• Providing jumper
~
I .
8
~I
w
• Provide the following 1 OOQ resistor.
• The capacitor inserted to the 11-pin connector must be installed in
the following manner.
8-8. Hints and tips
• Any parts must be closely attached on the PWB with solder.
• When replacing LSls, use the ALUMIT KR19RAM solder. (See
Service Information PS-009.)
• See the figure below for the installation of a 0.1uF inserted across v-
the KON (pin 26) of the gate array and the VGG side of a 0.033uF.
-6-
The contents of the memory will be erased with the following proce-
dure.
(1) Insert the RAM card.
(2) Press the RESET switch.
(3) Press the YES key. (Normally, the YES key may not be pressed,
but the YES key ON prompt
may
appear depending on the con-
tents of the RAM card.)
(4) Key in
[[)Gill:JGJ.
(5) The display will show 0.55555555555.
(6) After leaving the unit in the above state for more than 14
minutes, check that the power has been out.
8-7. Internal RAM capacity and auto-power off
functional checks
8-6. Ground continuity check
Check that the resistance between the display side cosmetic panel
and the RAM card lid is not more than 5 ohms.
8-5. Replacing the static tape
The static tape, once separated from the aluminum panel, should not
be used again. A new one must be used. Wipe residual glue off the
panel before attaching a new static tape. After the replacement,
check ground continuity in accordance with 8-6.
(Fig. 6)
(Fig.5)
(8) Solder the buzzer leads to the display-side bottom cabinet (CAB-
A) as shown in Fig.4. Next, fasten the terminal lug of the static
tape with a tapping screw. Also screw the other one. (Fig.5)
(9) Latch CAB-A with CAB-B.
(10) Close the unit halfway (Fig.6) and install the lower half key sheet
and the memory PWB on CAB-D.
(11) Install CAB-C.
(Fig.4)
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PC-1285