Hidden Menu Functions; Compressor And Compartment Heater - Teledyne 4700 Serivce Manual

ANALOG CURRENT:
__._ mA
5.2 Hidden Menu
Functions
PROGRAM CONFIGURE
VIEW LOG
5.2.1 Compressor and
Compartment Heater
ROOM=XXX REFRIG=YYY
COMPRESSOR ON/OFF
ROOM=XXX REFRIG=YYY
COMPARTMENT HEAT ON/OFF
ROOM=XXX REFRIG=YYY
REFRIG TEMP: ZZ C
Section 5 Electrical Troubleshooting and Diagnostics
2. The display shows the current reading until you press the
Stop or Enter button.
The display can include currents above 20 mA and below 4 mA,
and updates every 10 seconds. The reading should be within half
a milliamp of the actual current input.
The 4700 Sampler has several hidden service screens. These
screens are accessed by entering a numerical code number from
the standby menu screen.
In most cases, the numerical codes are based on telephone
keypad buttons, corresponding with the key words spelled out.
Each code must be followed with ENTER to be activated.
The hidden menu for controlling the compressor and com-
partment heater is accessed by entering the code 7378423
(SERVICE) from the main menu. On the top line of this screen
are two fields that will accept entries for room temperature and
refrigerator temperature. These values are expressed as
numbers between 230 and 999, representing temperatures
between -40 and 59.9° C, as shown in Table 5-1.
Line two of the screen shows the current state of the compressor,
compartment heater, and refrigerator temperature. Each value
appears for 3 seconds in rotation:
COMPRESSOR ON/OFF
COMPARTMENT HEAT ON/OFF
REFRIG TEMP: ZZ C
Enter values into the ROOM and REFRIG fields in order to
override the actual temperature values and control the com-
pressor and heaters for operational testing.
In addition to observing the state of COMPARTMENT HEAT
ON/OFF on the display, you can also confirm the heater oper-
ation by reaching in through either of the two square vents in the
rear of the compartment (Figure 5-3) and placing your hand on
the cover plate of the power supply. When the heater turns on,
you will feel the plate grow warmer.
4700 Refrigerated Sampler Service Guide
5-9