Cadex C4000 SERIES, User Manual

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Non-volatile
RAM ERROR Message
Service
When the unit is first turned on after replacing the back-
up battery, a non-volatile RAM ERROR message will
appear. To continue, press any Display Key. Pressing
the Key initializes the clock chip.
To verify correct operation, turn the power off and on
again while batteries are being serviced. The battery
data, date & time and print format should be retained - if
not, check the back-up battery.
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4. Replacing the EPROM
Identification
The EPROM is a 28-pin device mounted in a socket.
The EPROM is the only chip marked with a label.
Important
Replacement of the EPROM must be
performed only by a qualified technician. Observe the
static precautions when opening the C4000. Refer to "1.
Static Precautions"
in the chapter .
Warning
Before replacing the Back-up Battery, remove
all test batteries, turn the unit off and disconnect the
power cord.
1. Remove plastic floor section by unscrewing 5 screws.
(Two screws are located in the front rubber feet.)
Caution
Do not assert pressure on the Target Selector
switch when removing or installing floor section.
2.
Identify the EPROM and observe its orientation (refer to
Figure 13.2 at the end of this chapter). Note the
orientation of the notch at one end of the device.
3.
Use a designated IC remover or small blade screw
driver to gently lift the EPROM off the socket.
'Caution-Take care in handling the EPROM. Do not
bend the pins.
4. When installing the new EPROM, assure that all IC pins
are firmly plugged into the IC socket. Insure that the
notch is oriented towards the inside of the Motherboard .
13-5