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IV. Service Diagnosis
WARNING
1. This unit should be diagnosed and repaired only by qualified service
personnel to reduce the risk of death, electric shock, serious injury, or fire.
2. Risk of electric shock. Use extreme caution and exercise safe electrical
practices.
3. Moving parts (e.g., fan blade) can crush and cut. Keep hands clear.
4. Make sure all food zones are clean after the unit is serviced. For cleaning
procedures, see "VI. Cleaning Instructions."
A. Diagnostic Procedure
The diagnostic procedure is basically a sequence check which can be used at unit
startup or for system diagnosis. This procedure allows you to diagnose electrical system
and component failures. Before conducting the diagnostic procedure, check for proper
voltage per unit nameplate. The maximum allowable voltage variation is ±10 percent
of the nameplate rating. Check the control board S3 dip switch settings to assure that
they are in the factory default position. Check CB using the steps in "IV.B. Control Board
Check." For factory default settings, see "II.D.4.a) Default Dip Switch Settings." The
service menu may used to view history information. To access the service menu, press
and hold the up and down buttons and "ENTER" button simultaneously for 3 seconds.
Scroll through the service menu list using the "ENTER" button. For further details, see
"II.D.6. Service Menu." As you go through the diagnostic procedure, check to assure the
components energize and de-energize correctly. If not, those components or controls are
suspect. Always choose a white (W) neutral wire to establish a good neutral connection
when checking high voltages.
IMPORTANT
The maximum allowable voltage variation is ±10 percent of the nameplate
rating. 115VAC is used as reference voltage when checking voltage to
components. Voltage may vary depending on power supply.
1) Raise the front panel and move the power switch to the "OFF" position.
2) Unplug the unit from the electrical outlet.
3) Remove the control box cover.
4) Plug the unit back into the electrical outlet.
5) Move the power switch to the "ON" position.
6) The red "POWER OK" LED on CB comes on and stays on while the unit is in operation.
