User's Manual

Surface Mount Repair

RITRON surface mount products require special equipment and servicing techniques. Improper servicing

techniques can cause permanent damage to the printed circuit boards and/or components, which is not

covered by RITRON’s warranty. If you are not completely familiar with surface mounted component

repair techniques, RITRON recommends that you defer maintenance to qualified service personnel.

Precautions for Handling CMOS Devices

This radio contains complementary metal-oxide semiconductor (CMOS) devices, which require special

handling techniques. CMOS circuits are susceptible to damage by electrostatic or high voltage charges.

Damage can be latent, with no failure appearing until weeks or months later. For this reason, take

special precautions any time you disassemble the radio. Follow the precautions below, which are even

more critical in low humidity environments.

1) Storage/transport - CMOS devices that will be stored or transported must be placed in conductive

material so that all exposed leads are shorted together. CMOS devices must not be inserted into

conventional plastic “snow” or plastic trays of the type that are used for other semiconductors.

2) Grounding - All CMOS devices must be placed on a grounded bench surface. The technician that

will work on the radio/CMOS circuit must be grounded before handling the radio. Normally, the

technician wears a conductive wrist strap in series with a 100K Ohm resistor to ground.

3) Clothing - Do not wear nylon clothing while handling CMOS circuits.

4) Power off - Remove power before connecting, removing or soldering a PC board that contains

CMOS devices.

5) Power/voltage transients - Do not insert or remove CMOS devices with power applied. Check all

power supplies to be used for testing CMOS devices, making sure that no voltage transients are

present.

6) Soldering - Use a grounded soldering iron for soldering CMOS circuitry.

7) Lead-straightening tools - When straightening CMOS leads, provide ground straps for the tool used.

Synthesizer Shield

The synthesizer shield should not be removed, unless a component must be replaced. This shield is

soldered to the main PC board.