Repair And Replacement; Performance Checks - Racal Instruments 3151 User Manual

3151 And 3151A User Manual
Repair and
Replacement
Performance
Checks
Repair and replacement of electrical and mechanical parts must be
accomplished with great care and caution. Printed circuit boards can
become warped, cracked or burnt from excessive heat or mechanical
stress. The following repair techniques are suggested to avoid
inadvertent destruction or degradation of parts and assemblies:
1. Use a 60/40 solder and temperature-controlled 35 - 40 watt pencil-
type soldering iron on the circuit board. The tip of the iron
should be clean and properly tinned for best heat transfer to
the solder joint. A higher wattage soldering iron may separate
the circuit from the base material.
2. Keep the soldering iron in contact with the PC board for a
minimum time to avoid damage to the components or printed
conductors.
3. To desolder components, use a commercial "solder sucker" or a
solder-removing SOLDER - WICK, size 3.
4. Always replace a component with an exact duplicate as specified
in the parts list.
The following performance checks verify proper operation of the
instrument and should normally be used:
1. As a part of the incoming inspection of the instrument
specifications;
2. As part of the troubleshooting procedure;
3. After any repair or adjustment before returning the instrument to
regular service.
Maintenance and Performance Checks 5-3