Control Diagnostic Function (Models N640, N641, N640-Im, N641-Im, N840, N841,N840-Im,And N841-Im) - Norcold N620 Service Manual

Diagnostic Screen #8: Outputs
Individual segments appear for these outputs from the
refrigerator controls:
Segment 1 ............ The power board is supplying power to
the AC heater.
Segment 2 ............ The power board is supplying power to
the DC heater.
Segment 3 ............ The power board is supplying power to
the divider heater.
Segment 4 ............ The power board is supplying power to
the gas valve.
Segment 5 ............ The power board is supplying power to
the interior light.
Segment 6 ............ The power board is supplying power to
the spark electrode.
Diagnostic Screen #9: DC Voltage Status
The screen number appears in the left display. The individual
segments of the right display appear for the status of the DC
voltage:
Segment 1 ............ DC voltage high.
Segment 4 ............ DC voltage normal.
Segment 7 ............ DC voltage low.
Control Diagnostic Function
(models N640, N641, N640-IM, N641-IM,
N840, N841, N840-IM, and N841-IM)
The Control Diagnostic Function allows the repair technician
to put the refrigerator control into a diagnostic display mode.
This mode provides the repair technician with specific
diagnostic information which can be helpful when trouble-
shooting refrigerator control problems.
The diagnostic display mode consists of ten different display
screens. While each of these screens show different informa-
tion, they all use the individual segments of the 7-segment
displays. The individual segments are:
s e g m e n t 2
s e g m e n t 5
To put the refrigerator control into the diagnostic display
mode, push the TEMP SET and MODE buttons at the same
time and hold them for five seconds. "1", which means
diagnostic screen #1, will appear for two seconds on the left
display. The contents of diagnostic screen #1 will then
appear until you push the MODE button again.
Service Manual 20
s e g m e n t 1
s e g m e n t 3
s e g m e n t 4
s e g m e n t 6
s e g m e n t 7 A rt01 075
Each time you push the MODE button, the next diagnostic
screen # appears for two seconds and then the contents of
the diagnostic screen appears. After screen # 0 (ten), the
diagnostic screens start again with screen #1.
Diagnostic Screen #1:
All display segments appear on both displays.
Diagnostic Screen #2:
No display segments appear on either display.
Diagnostic Screen #3: Thermistor Temperature
The thermistor temperature appears in °F
displays.
Diagnostic Screen #4: Fault History
The screen number appears in the left display. The individual
segments of the right display appear for these recorded
faults:
Segment 1 ............ Ignition fault.
Segment 2 ............ Door ajar.
Segment 3 ............ DC voltage low.
Segment 4 ............ DC voltage high.
Segment 5 ............ AC mode selected but not available.
Segment 6 ............ AC relay stuck closed.
Segment 7 ............ AC heater failed open.
Diagnostic Screen #5: Fault History - Continued
The screen number appears in the left display. The individual
segments of the right display appear for these recorded
faults:
Segment 1 ............ Thermistor failure.
Segment 2 ............ Flame sense failure.
Segment 3 ............ DC relay stuck closed.
Segment 4 ............ DC heater failed open.
Segment 5 ............ AC voltage low.
Segment 6 ............ AC heater failed open.
Diagnostic Screen #6: Erase Fault History
"E" "r" appears for one second and then pauses for two
seconds. The cycle continues to repeat as long as this
display screen is active.
To erase the fault history:
- Push "TEMP SET" for five seconds.
- "C" "L" appears for one second and then pauses for
two seconds.
- The cycle continues to repeat as long as this state is
active.
using both