43C-RD9A
50C-RD9A/9H
Fuses and Conventional Resistor Removal/ReplacementAt Other Connections
1. Clip each fuse or resistor lead at top of circuit board holloUse the following technique to repair defwective copper pattern
stake.at connections other than IC Pins, This technique involves
the installation of a jumper wire on the component side of the
2. Securely crimp leads of replacement component aroundcircuit board.
stake 1/8 inch from top.
3. Solder the connections.
CAUTION: Maintain original spacing between the
replaced component, and adjacent
components and the circuit board, to prevent
excessive component temperatures.
Circuit Board Foil Repair
Excessive heat applied to the copper foil of any printed circuit
board will weaken the adhesive that bonds the foil to the circuit
board, causing the foil to separate from, or "lift-off", the board.
The following guidelines and procedures should be followed
whenever this condition is encountered.
In Critical Copper Pattern Areas
High component/copper pattern density and /or specialInsulated Jumper Wire
voltage/current characteristics make the spacing and integrity
of copper pattern in some circuit board areas more critical1. Remove the defective copper pattern with a sharp knife.
than in others. The circuit foil in these areas is designated asRemove at least 1/4 inch of copper, to ensure hazardous
Critical Copper Pattern. Because Critical Copper Pattern
requires special soldering techniques to ensure thecondition will not exist if the jumper wire opens.
maintenance of reliability and safety standards, contact your2. Trace along the copper pattern from both wire sides of the
SHARP personnel.pattern break and locate the nearest component directly
connected to the affected copper pattern.
At IC Connections
To repair defective copper pattern at IC connections, use the
following procedure to install a jumper wire on the copper3. Connect insulated 20-gauge jumper wire from the nearest
component on one side of the pattern break to the lead of
pattern side of the circuit board. (Use this technique only onthe nearest component on the other side.
IC connections.)Carefully crimp and solder the connections.
1. Carefully remove the damaged copper pattern with a sharpCAUTION : Be sure the insulated jumper wire is dressed
knife,(Remove only as much copper as absolutelyso that it does not touch components or sharp
necessary.)
edges.
2. Carefully scratch away the solder resist and acrylic coatingFrequency Synthesis (FS) Tuning Systems
(if used) from the end of the remaining copper pattern.1. Always unplug the instrument AC power cord before
disconnecting or reconnecting FS tuning system cables
Install Jumper Wire and Solder
and before removing or inserting FS tuning system
modules.
2. The FS tuner must never be disconnected from the FS
tuning control module while power is applied to the
instrument .
3. When troubleshooting intermittent problems that might be
caused by defective cable connection(s) to the FS tuning
system, remove the instrument AC power as soon as the
defective connector is found and finish confirming the bad
connection with a continuity test. This procedure will reduce
3. Bend a small "U" in one end of a small-gauge jumper wirethe probability of electrical overstress of the FS system
semi-conductor components.
and carefully crimp it around the IC pin. Solder the IC
connection.
4. Route the jumper wire along the path of the cut-away
copper pattern and let it overlap the previously scraped
end of the good copper pattern. Solder the overlapped
area, and clip off any excess jumper wire.
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