Page 12
6-12
PROBLEM
POSSIBLE CAUSE
TEST / ACTION
#7031933 - Revision A - April, 2015
Troubleshooting Guides
MODEL 424
MODEL 424
(SWS #3227000)
(SWS #3227000)
I.
NO LIGHTS
J.
CONTROL PANEL KEYS
MALFUNCTIONING
K. NO LED’s
L.
ALL LED’s LIT
M. SAME LED SEGMENTS
MISSING FROM BOTH DIS-
PLAY WINDOWS
N. LED SEGMENTS MISSING
FROM ONLY ONE DISPLAY
WINDOWS
O. DOOR / UNIT UN-LEVEL
Unit in Sabbath Mode
Door Switch Disconnected or
Malfunctioning
Fan Relay Disconnected or
Malfunctioning
Light Strips Burned-out
No Power from Control Board
Control Panel Ribbon Cable Plugged in
Wrong
Control Panel or Ribbon Cable
Defective (OR) No Signal Read at
Control Board
Unit Switched OFF
LED Ribbon Cable Plugged in Wrong
No Data from Control Board
Bad Data from Control Board
Bad Data from Control Board
Bad LED Board in Control Panel
Door or unit needs adjustment
Press & release UNIT ON/OFF key.
Check switch electrical connections. Check
for power to / from switch. Reconnect or
replace switch if defective.
Check relay electrical connections. Check for
power to / from relay (pins 1 & 5 and 7 & 8).
Reconnect or replace if defective.
If power from switch and relay, replace light
strips.
Check for power at E3 of control board. If no
power, replace board.
Check control panel ribbon cable at control
panel (silver area of terminal away from con-
trol board). Plug in correctly if incorrect.
SEE CONTROL PANEL TEST PROCEDURE
AT BACK OF TROUBLESHOOTING GUIDE
SECTION.
Press UNIT ON/OFF key
Check LED ribbon cable. Plug in correctly if
incorrect.
Replace Control Board
Replace Control Board
Replace Control Board
Replace Control Panel Assembly
SEE INSTALLATION MANUAL
