TTI TG501, Руководство по обслуживанию

Страница: 2 / 33

Table of Contents
General 1
Specification 2
Functional Description 4
Circuit Descriptions 6
Calibration 13
Parts List 17
General
Service Handling Precautions
Service work should only be carried out by skilled engineers. Please note that the tracks on the
printed circuit board are very fine and may lift if subjected to excessive heat. Use only a miniature
temperature controlled soldering iron and remove all solder with solder wick or suction before
attempting
to remove a
c
omponent.
Dismantling the Instrument
WARNING!
Opening the instrument is likely to expose live parts. The instrument shall be disconnected from all
voltage sources before any adjustment, replacement or maintenance and repair during which it shall
be opened. If afterwards any adjustment, maintenance or repair of the opened instrument under
voltage is inevitable, it shall be carried out only by a skilled person who is aware of the hazards
involved.
1. Remove the 8 side screws and lift off the case upper and lower.
2. Access to all components is now possible, further dismantling is not necessary.
3. All small knobs are push on types. To remove the dial, remove the cap in the centre of the
knob using a knife blade, then loosen the nut about 1 turn. The knob and dial can then be
pulled off.
4. Transistors Q32, Q34 and Q39 and IC22 are insulated from the rear panel.
5. Reassemble in reverse order.
Operating Voltage
See the Power Supply section for details of changing the operating voltage from 220/240 to 110/120
and vice-versa.
1