SERVICE MANUAL
Medi-Therm II
w
w
w
.g
aymar
.com P/N 10187-000 7/98
TROUBLESHOOTING CHARTS
Is a steel object
attracted to center top of
the valve?
*
*
**
Yes
Connect
test setup
as shown
in figure 13.
No
Yes
Assume Q8 triac
is also damaged.
Repair/replace
power supply
board.
Repair/replace
hot solenoid
SV2.
Suspect Q8 or
U7.
Repair/replace
power supply
board.
Is
hot solenoid
coil SV2
shorted
?
If thermometer in
TPT9 contradicts
this, suspect RT2.
No
Is
blanket display
within 1°C of
setpoint
?
No
Yes
No
No
Yes
Yes
No
Yes
No
Yes
No
Yes
Suspect
board-to-board
connection.
Repair.
Suspect
control/display
board.
Repair/replace.
Suspect Q9 or U8.
Repair or replace
power supply
board.
Is pin 9
ref to pin 10
of U51
0 VDC?
Suspect
board-to-board
connection.
Repair.
Suspect
base-to-power
supply board
connection.
Repair.
Is
optocoupler U7
input pulled
low?
Disconnect hot
solenoid SV2.
Measure coil
resistance for
short.
Repair/replace
hot solenoid
SV2.
Line
voltage at output
of Q8?
Suspect
base-to-power
supply board
connection.
Repair.
Is SV2 coil
energized?
Line
voltage at
terminals 2
and 3 of
TB1?
Check
hot solenoid SV2
(it should be on).
See
"PUMP MOTOR
NOT RUNNING"
(figure 6J)
Is
pump
running
?
Check pump
(it should be
running)
Select MANUAL mode.
Adjust setpoint to 41°C.
Allow machine time to
heat (30 minutes max.)
BLANKET WON’T
HEAT IN AUTO OR
MANUAL MODE
**
Figure 6K—Blanket Won't Heat in Auto or Manual Mode, Page 1 of 2
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