15
MAINTENANCE
HPRS Series
5.3 Schematic and Replacement Parts
Refer to Figure 5.1 for a basic schematic of the HPRS
decade unit.
If you must order parts, give the model number and
serial number from the bottom label. and a detailed
description of the part or assembly.
5.4 Troubleshooting
If the verifi cation procedure results in a failure, disas-
semble the unit as described below, and examine the
parts in question to determine the necessary repair
or replacement.
5.5 Disassembly, Component
Replacement, and Reassembly
It is recommended that service be performed only by
IET Labs or by qualifi ed personnel.
5.5.1 Disassembly
Referring to Figure 5.2 to locate part numbers, pro-
ceed as follows:
1. Work in a clean environment.
2. Place the instrument on a fl at surface and remove
the 4 housing screws from the bottom of the instru-
ment. The housing may now be removed.
5.5.2 Component Replacement
Determine and locate any faulty component that
requires replacement.
To remove a decade switch assembly proceed as
follows:
1. Label and unsolder the bus wires connecting the
switch assembly to the resistive loads.
2. Loosen the screw holding the knob on the switch
shaft and remove the knob.
3. Remove the nut holding the switch assembly on
the front panel and remove the assembly.
4. Replace the assembly by reversing the above steps,
making certain that the knob screw is aligned with
the fl at portion of the switch shaft.
5.5.3 Reassembly
1. Make certain that the 4 standoffs have not become
loose; tighten as required.
2. Replace the housing: line up the holes in the
standoffs with the holes in the case, and install the 4
housing screws.
5.6 Customer Service
The IET warranty attests to the quality of materials
and workmanship in our products. For application
assistance or if diffi culties occur, our engineers will
assist in any way possible. If you cannot eliminate the
diffi culty, please e-mail, FAX, or phone our Service
Department, giving full information of the trouble
and of steps taken to remedy it. Be sure to include
the type and serial number of the instrument.
Call 516-334-5959 for technical support or customer
service
www.ietlabs.com
