Pace ST 115 Operation & Maintenance Manual page 38

Handpieces
The following "Heater Assembly Checkout Procedures" (Table 4) is applicable to
all PACE SensaTemp handpieces used with the ST 115 system except for the TT-
65 and DTP-80handpieces. Refer to the applicable manuals for troubleshooting
procedures pertinent to that handpiece. Perform the procedures with the
handpiece heater at room temperature. If the heater is warm, resistance readings will
be different from those shown. Disconnect the handpiece from the power source.
Use a meter to check resistance across the handpiece connector plug pins as
outlined in the "Checkout Procedure" column.
Symptom Checkout Procedure
Handpiece Check resistance - Pin 2 to
does not heat. Pin 5. Refer to "Heater
Specifications" column.
If resistance is high - -
Check resistance - Pin 3 to
Pin 6. If circuit reads open -
-
Handpiece Check resistance - Pin 3 to
overheating. Pin 6. Resistance should be
110 ohms. If resistance is
less than 105 ohms - -
Fuse blows Check resistance - Pin 2 to
when unit is Pin 5. Refer to "Heater
turned on. Specifications" column. If
resistance is low - -
No Ground on Check resistance - Pin 4 to
Tip. a NEW Tip. Resistance
should be less than 2 ohms.
If not - -
Heater Specifications
PS-80 = 8-10 ohms
SX-80 = 8-10 ohms
SX-70 = 8-10 ohms
TP-65 = 9-11 ohms
TJ-70 = 6-8 ohms
Table 4. Heater Assembly Checkout Procedures
34
Cause Solution
Open Heater Replace Heater
Assembly.
Open Sensor Replace Heater
Assembly.
Shorted Replace Heater
Sensor Assembly.
Shorted Replace Heater
Heater Assembly & Fuse.
Oxidation in Clean Heater Bore
Heater Bore. using appropriate
wire brush.
Defective Replace Heater
Heater Assembly.
Connector
Plug Pinouts
Repair