Service Manual — COATS Models 950/950 ProRacer/1025/1050/1055 • 11
Turn the power
switch ON.
Is the power switch set
to the ON position?
Is the proper voltage and ground
present at the receptacle? See
AC CheckingProcedure
No
Yes
Has one of the 3A breakers on
the power panel tripped?
Is there between 200 & 230VAC
between the terminals marked 0V
& 230V on the transformer?
Disconnect the 2 RED wires
from the circuit breakers. Is
there 20VAC between these 2
RED wires? Reconnect wires.
Replace the transformer, See
Replacement Procedure
Turn the power off and unplug the
machine. Check the continuity of
the two (2) 3A circuit breakers.
If either of the breakers are open,
try resetting and rechecking. If
the breaker remains open & does
not trip, replace the breaker.
Connect the machine to a power
source and turn the power switch
ON. Is there 20VAC between
pins 1 & 2 on the connector on
the right side of the PCB?
Turn the power off and unplug
the machine. Turn the power
switch to the ON position. Check
the continuity of the wire from the
230V terminal on the transformer
to terminal 4 (950) or terminal 64
(1050) on the forward contactor.
Is there 220VAC between
terminals 4 & 6 on the
forward contactor?
Is there 220VAC between
terminals 4 & 6 on the
brake contactor?
Yes
Yes
No
Yes
No
No
Check the continuity of the
power cord from the terminals to
the appropriate connection on
the brake contactor.
Repair or replace
the defective wire
or connection.
Checks
Bad
Checks Good
Breaker
Trips
Checks
Bad
Yes
No
Yes
No
No
No
Yes
Have the voltage supply
to the machine
corrected.
Replace or repair the defec-
tive jumper wire from the
forward to brake contactor.
Replace the PCB. See
Replacement Procedure
Reset the tripped breaker. If the
breaker trips again, replace the PCB.
See Replacement Procedure
Yes
Turn the power off and unplug the
machine. Check the continuity of
the RED wires from the trans-
former pins 1 & 2 on the connec-
tor on the right side of the PCB.
Checks
Good
Repair or replace the
defective wire or connection.
Checks
Bad
Check the continuity of the wire
from the terminal marked 0V on
the transformer to terminal 6 on
the forward contactor.
Checks
Good
Checks
Bad
Replace the power switch, See
Replacement Procedure
Check the continuity of
the power switch.
Checks Bad
Checks Bad
Checks
Good
Direct Drive
Display Does Not Light (Contactor Model)