Lubrication; Semiconductor Checks; Periodic Readjustment - Tektronix 2205 Service Manual

M aintenance-2205 Service
Item
Circuit Boards
Resistors
Solder Connections
Capacitors
Wiring and Cables
Chassis
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a
i CAUTION 5
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Most spray-type circuit coolants contain
Freon 12 as a propellant. Because many
Freons adversely affect switch contacts, do
not use spray-type coolants on the switches
or attenuators. Carbon based solvents will
damage the circuit board material.

LUBRICATION

Most of the potentiometers used in this instru­
ment are permanently sealed and generally do not
require periodic lubrication. All switches,
rotary- and lever-type, are installed with proper
lubrication applied where necessary and wilt rarely
require any additional lubrication. A regular periodic
lubrication program for the instrument is, therefore,
not recommended.
6-4
Table 6-3
internal Inspection Checklist
Inspect For
Loose, broken, or corroded solder
connections. Burned circuit boards.
Burned, broken, or cracked
circuit-run plating.
Burned, cracked, broken, or
blistered.
Cold solder or rosin joints.
Damaged or leaking cases.
Corroded solder on leads or
: terminals.
Loose plugs or connectors. Burned,
broken, or frayed wiring.
Dents, deformations, and damaged
hardware.
i
both
Clean solder corrosion with an
eraser and flush with isopropyl
alcohol. Resolder defective con­
nections. Determine cause of
burned items and repair. Repair
defective circuit runs.
Replace defective resistors. Check
for cause of burned component
and repair as necessary.
Resolder joint and clean with
Isopropyl alcohol.
Replace defective capacitors. Clean
solder connections and flush with
isopropyl alcohol.
Firmly seat connectors. Repair or
replace defective wires or cables.
Straighten, repair, or replace
defective hardware.

SEMICONDUCTOR CHECKS

Periodic checks of the transistors and other
semiconductors in the oscilloscope are not recom­
mended. The best check of semiconductor per­
formance is actual operation in the instrument.

PERIODIC READJUSTMENT

To ensure accurate measurerrienfs. check the
performance of this instrument every 2000 hours of
operation, or if used infrequently, once each year. In
addition, replacement of components may ne­
cessitate readjustment of the affected circuits.
Complete performance check and adjustment in­
structions are given in Sections 4 and 5. The per­
formance cheek procedure can also be helpful in
localizing certain troubles in the instrument. In some
cases, minor problems may be revealed or cor­
rected by readjustment. If only a partial adjustment
is performed, see the interaction chart, Table 5-1,
for possible adjustment interaction with other
circuits.
Repair Action