Testing & Troubleshooting; Trouble Shooting Guide - Garland Moisture+ MPOE5L Service Manual

Trouble Shooting Guide

PROBLEM
Fan Will not Run
Key Pad Buttons Not
Responding
PROBE ERROR
in display
HI TEMP
In display
HELP
In display
Unit will not shut off
No HIGH speed But LOW
speed works
No LOW speed But HIGH
speed works
Display is BLANK
NO POWER
Unit will not heat
Motor stops, then after
a period of time comes
back on
Page 18
TESTING & TROUBLESHOOTING
POSSIBLE CAUSE
• No power to unit
• No power to motor
• Micro switch not OPENING
• Defective key pad
• Loose ribbon connection at key
pad
• Faulty Probe
• Loose probe connection
• Oven at too high a temp for
product
• Faulty Probe
• Motor centrifugal switch stuck
• Contactor stuck
• Unit above 150°F
• Bad key pad
• Bad K2 relay on board
• Bad motor
• Bad key pad
• Bad K3 relay on board
• Bad motor
• Blown fuse(s)
• Bad transformer
• Bad harness connection
• No power out of K4 relay
• Blow fuse
• Hi Limit open
• Coil on contactor
• Motor centrifugal not closing
• Thermal Trip on motor
CORRECTIVE ACTION
• Turn power on
• Check fuses
• Check connections
• Use key pad diagnostics / pin outs
test points
• Check connection
• Replace probe
• Check connections
• Allow oven to cool
• Replace probe
• Check centrifugal switch
• Check contactor
• Put unit into cool down, open door
slightly
• Use diagnostic KEY PAD TEST
• Check for voltage out of K2 relay
• Check motor
• Use diagnostic KEY PAD TEST
• Check for voltage out of K3 relay
• Check motor
• Check F1 & F2 fuses
• Check for 24VAC out of TR2
transformer
• Check connections
• Check for power out of K4 relay
• Check F1 fuse
• Check HI LIMIT in flue box
• Check for voltage at contactor coil
• Check motor centrifugal switch
• Inspect rear clearance
• Motor air intake is clear of
lint/debris
• Replace motor
Document #MPOELSVC0504