GE DPGT750EC/GC Technical Service Manual page 41

PROBLEM POTENTIAL CAUSE
Long Dry Time
Dryer Not
Heater error (Gas)
Heating
continued
Low line voltage
No gas supply
Ignitor failure
Flame detector failure.
ON/OFF gas valve failure
Linear Gas Valve Failure
Thermostat failed open
Centrifugal switch failure
Thermistor failure
Won't Start -
controls dead
Low L1 voltage
Tripped safety thermostat
Defective main control board
Defective inverter board
Broken Belt
Won't start -
controls OK
Open winding on drum motor
Door switch failure (door open)
Centrifugal switch failure
DIAGNOSTIC PROCEDURE
Check service mode for heater error.
Line voltage must be greater than 96V.
Software will not allow gas valves to
operate below 96VAC.
Check gas valve and pressure.
With front panel removed and door switch
reconnected, start a cycle and check for
ignitor glow. If ignitor doesn't glow, check
ignitor resistance at the ignitor connector
(100 - 500 Ohms).
With front panel removed and door switch
reconnected, start a cycle and check that
ignitor turns on/off.
Check resistance of ON - OFF valves
(1800 - 1900) ohms.
Check resistance of linear valve (60 - 70)
ohms.
Check continuity of Outlet and Hi-Limit
thermostats.
Check centrifugal switch continuity in open
and closed state, according to the
terminals shown on the mini-manual.
Check room-temperature resistance of
thermistor. Outlet thermistor resistance
range is 10K+-3% @ 25C, inlet thermistor
range is 2.27K +- 5%.
Check L1 voltage at outlet.
Check safety thermostat continuity
Check service mode
Check service mode
Remove front panel. Check belt.
Check resistance of start and run
windings. Should be approximately
7.2 Ohms for start winding and 3.1 Ohms
for run winding.
Check if switch is connected. Check if
lamp works. Check if dryer runs with door
open.
Check centrifugal switch continuity in open
and closed state, according to the
terminals shown on the mini-manual.
– 41 –
ACTION
If heater error is displayed,
proceed with diagnostic
procedures in the order below.
Inform owner of low line voltage.
Open valve. Inform consumer of
no gas pressure.
Replace ignitor
Replace flame detector.
Replace valve assembly.
Replace valve assembly.
Replace appropriate thermostat.
Replace drum motor.
Replace thermistor.
If zero (0), check circuit breaker
or fuses. If below 30V, the
controls will not operate. Tell
consumer to call electrician.
Reset or replace if necessary.
Replace control board
Replace inverter board
Replace belt.
Replace drum motor
Connect or replace door switch.
Replace drum motor.