General Maintenance
WFM700 Series Waveform Monitors Service Manual 4-5
Inspection — Interior. To access the inside of the instrument for inspection and
cleaning, refer to the Removal and Installation Procedures in this section.
Inspect the internal portions of the instrument for damage and wear, using
Table 4--2 as a guide. Defects found should be repaired immediately.
CAUTION. To prevent damage from electrical arcing, ensure that circuit boards
and components are dry before applying power to the instrument.
Table 4- 2: Internal inspection check list
Item Inspect for Repair action
Circuit boards Loose, broken, or corroded
solder connections. Burned
circuit boards. Burned, broken, or
cracked circuit-run plating.
Remove and replace damaged
circuit board.
Resistors Burned, cracked, broken, blis-
tered condition.
Remove and replace damaged
circuit board.
Solder connections Cold solder or rosin joints. Resolder joint and clean with
isopropyl alcohol.
Capacitors Damaged or leaking cases.
Corroded solder on leads or
terminals.
Remove and replace damaged
circuit board.
Semiconductors Loosely inserted in sockets.
Distorted pins.
Firmly seat loose semiconduc-
tors. Remove devices that have
distorted pins. Carefully straight-
en pins (as required to fit the
socket), using long-nose pliers,
and reinsert firmly. Ensure that
straightening action does not
crack pins, causing them to
break off.
Wiring and cables Loose plugs or connectors.
Burned, broken, or frayed wiring.
Firmly seat connectors. Repair or
replace modules with defective
wires or cables.
Chassis Dents, deformations, and dam-
aged hardware.
Straighten, repair, or replace
defective hardware.
