Thermador SMW 272 B Service Manual page 76

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Lower O ven Section
KEY PRESSED
Stop T ime
Speaker will beep.
Clock
All the display segments are lit.
Cook T ime
Any error codes stored in the EEPRO M will be displayed. The time digits will display the
last display head error code. The upper oven temperature digits will display the last up-
per oven relay board error code. The lower oven temperature digits will display the last
lower oven relay board error code. If no error codes exist, F0 is displayed.
The error codes stored in the EEPRO M can be cleared by pressing and holding both the
CO O K TIME and STO P TIME keys for 5 seconds while in the test mode.
0 - 9 Keys
Corresponding number is displayed in the blue digits
The control will exit the test mode by two methods. First, by pressing either O FF key, and second, by using
a 16 second timer. Sixteen seconds after the last key action, the test mode will be cancelled.
T EST IN G T H E TOUCH
CON T ROL PADS
The control panel is comprised of the following (see the
illustration):
• Control Panel Frame
steel). The control panel brackets are mounted
on the frame and a bullet pin (see the small inset
at the top of the illustration) is screwed onto the
brackets.
Control Panel Glass.
•
brackets are glued to the control glass.
The S-Model oven control panel is mounted to the front
subpanel with two bullet pins and four screws (see
46
in this manual for the removal procedure).
BRACKET
SCREW (4)
BEZEL
GLASS BRACKET
– +
R84
P3
– & + TEST PADS
A ribbon cable connects the control board to the touch
control board. O ne end of the cable has an edge connec-
(black, white, stainless
The control board and
Bullet
Pin
Screw
CONTROL BOARD
GLASS BRACKET
FRONT PANEL
GLASS ASSEMBLY
ACT IO N
.
tor that connects to the touch control board pins. The
pin connector on the board and the edge connector are
both indexed (the # 4 pin is missing and the correspond-
ing # 4 pin opening is plugged) to prevent the connector
from being reversed.
The touch control board has 28 touch pads, however,
not all of the pads are active. For example, a unit with no
lower oven convection feature will not have a position
on its control panel glass for that function. Thus, the
control board touch pad at that location will not be used.
The touch pads operate as follows:
1. An electromagnetic field surrounds each touch pad
so that when the glass over a pad is touched, the
Page
field is disturbed.
2. The disturbance in the field is sensed by the micro-
processor on the touch control board as a mode,
or a command.
The touch control board has a positive and a negative
test pad (see the small inset at the bottom of the
illustration). To test the board:
1. Set a volt meter to read 10-volts D .C.
2. Touch the meter test probes to the
circles
of the touch control board's positive and
negative test pads (do not touch the green solder
resist area at the centers).
• The meter should indicate 0-volts when a
touchpad is activated.
• The meter should indicate 5-volts D .C. when no
touchpad is activated.
Page 74
SMW O ven Service Manual
bare foil