Pace ST 25, Operation And Maintenance Manual

©2001 PACE Inc., Laurel, Maryland

Page 11 of 14

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temperature is off by more than ±15°C, the handpiece may require maintenance.
Recheck the temperature using a second handpiece.

4. Carefully lock the Variable Temperature Control in position by tightening the inner set

screw (closest to front panel).

5. Loosen the outer set screw on the Variable Temperature Control

knob (furthest from front panel) using the Temp. Locking Key
(hex key) supplied with the system.  Position the knob with the
pointer aligned to match the temperature indicated on the
temperature meter.  Secure the knob in position by tightening the
outer set screw.

6.  Loosen the inner set screw to unlock the Variable Temperature

control if adjustment of operating tip temperature is desired.

Corrective Maintenance

Power Source

Most malfunctions are simple and easy to correct.  Refer to Table 3.

Symptom

Probable Cause

Solution

No power to
system

Blown Fuse

Check handpiece using table 4.  Replace the fuse
(located in the AC Receptacle Fuse Holder) with
one of the same rated value (see Table 6, Spare
Parts)

Defective Heater

See Table 4.

Handpiece will
not heat

Power Source
Malfunction

Contact PACE

Table 1:  Power Source Corrective Maintenance

Handpieces

The following “Heater Assembly Checkout Procedures” (Table 2) is applicable to all PACE
SensaTemp handpieces used with the ST 25 or ST 35 system except for the TT-65 and DTP-80
handpieces.  Refer to the applicable manuals for troubleshooting procedures pertinent to these
handpieces.
Perform the procedures with the handpiece heater at room temperature.  If the heater is warm,
resistance readings will be different from those shown in Table 2.  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.

Problem

Checkout Procedure

Cause

Solution

Check resistance:  Pin 2 to
Pin 5.  Refer to heater
specifications below if
resistance is high, see
Solution

Open Heater

Replace Heater Assembly

Handpiece does not heat

Check resistance:  Pin 3 to
Pin 6.  If circuit reads open,
see Solution

Open Sensor

Replace Heater Assembly

Handpiece Overheating

Check Resistance:  Pin 3 to
Pin 6.  Resistance should
be 110 ohms.  If resistance
is less than 105 Ohms, see
Solution

Shorted Sensor

Replace Heater Assembly

Fuse blows when power
source is turned on

Check resistance:  Pin 2 to
Pin 5.  Refer to heater
specifications below if
resistance is low, see
Solution

Shorted Heater

Replace Heater Assembly
and Fuse