Trouble shooting guide – Garland 200 User Manual

Page 88

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Page 88

Part # MCOSM06 Rev 1 (11/03/08)

Trouble Shooting Guide

PROBLEM

POSSIBLE CAUSE

CORRECTIVE ACTION

Fan will not run

A. No power to unit

B. No power to motor from

relay board

C. Micro switch no closing

A. Turn power on

B. Check for voltage from relay board

to motor

C. Check micro switches

Button on key pad

not responding

A. Loose ribbon

connection between key

pad and smart board

B. Faulty key pad

A. Check that ribbon connection from

key pad is attached to smart board

B. Refer to key pad testing procedure

on bulletin # B-107-2001

‘Prob’ in display

A. Probe disconnected

B. Probe has failed

A. Re attach probe

B. Confirm ohm resistance of probe.

Refer to cavity probe chart for

readings

C. Check for continuity between probe

connection at relay board, probe

harness & probe

Unit will not shut off

A. Cavity temperature

above 150°F

A. Normal operation. Unit will not go

to OFF until cavity temperature is

below 150°F

No HIGH speed

BUT HIGH speed

LED is illuminated

on key pad

A. Bad relay board

B. Bad smart board

A. CR3 on relay board should be on, if

not check for 24VDC +/- 10% at

pins 5 & 7 at relay board. If voltage

present replace relay board

B. Check for 24VDC +/- 10%between

pins 5 & 7 at relay board. If voltage

is not present replace smart board

No LOW speed BUT

LOW speed LED is

illuminated on key

pad

A. Bad relay board

B. Bad smart board

A. CR4 on relay board should be on, if

not check for 24VDC +/- 10% at

pins 5 & 8 at relay board. If voltage

is present replace relay board

B. Check for 24VDC +/- 10% at pins 5

& 8 at relay board. If voltage is not

present replace smart board.

Unit will not heat.
DOOR

shown in

display

A. Open circuit on upper

door switch

A. Unplug unit from supply. With door

closed between NO and COM

switch should be open.

B. With door

open to 30° angle switch

should be closed

C. With

door open all the way switch

should be closed

Unit will not turn ON

when button pushed,

display reads OFF

A. Loose ribbon

connection between key

pad and smart board

B.

Faulty key pad

A. Check connection

B. Refer to key pad testing procedure

on bulletin # B-107-2001

Page 2 of 9

1-800-427-6668 www.garland-group.com Fax: 1-800-361-7745

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