23
Mynute
FAULT FINDING TEST ‘A’ (Mynute 28e-35e): turn the selector switch to the reset position
START
Status LED
is green
Go to test "C"
Status LED
is red
Does the
selector knob
rotate the
switch on the
display PCB
Status LED
is blank
Have the
fuses been
checked
NO
NO
YES
YES
Have the
electrical
checks as
detailed in 7.7
been carried
out
Does the
selector knob
rotate the
switch on the
display PCB
NO
Replace
selector knob
NO
Replace
selector knob
YES
Is there
5vdc across
terminals
M9.1 & M9.2
on main PCB
YES
Is there
5vdc across
terminals
M2.1 & M2.2
on main PCB
Go to test "B"
YES
Replace
display PCB
YES
NO
Replace main
PCB
NO
Replace ribbon
cable between
main PCB &
display PCB
START
Display
shows 01
Display
shows 02
Display
shows 03
Display
shows 04
RESET
Check gas
supply
Display
shows 06
Display
shows 07
RESET
Ensure JP5
tag is on
Check
thermistor
values and/or
replace
Go to test "C"
Replace main
PCB
Check wiring
and continuity
Display
shows 08
Check
gas
pressure
Check continuity
and/or replace
thermostat
FAULT FINDING TEST ‘B’ (Mynute 28e-35e): turn the selector switch to the “on” position