General
Service Handling Precautions
Service work or calibration should only be carried out by skilled engineers. Please note the
following points before commencing work.
The tracks on the printed circuit board are very find and may lift if subjected to excessive heat.
Use only a miniature temperature controlled soldering iron and remove all solder (on both sides of
the joint) with solder wick or suction before attempting to remove a components.
Many of the integrated circuits are CMOS devices and are should be taken when handling to
avoid damage by static discharge.
Dismantling the instrument
1. Invert the instrument and remove the 4 screws next to the rubber feet.
2. Lift off the case lower ensuring the front and rear panels stay with the case upper.
3. Remove the 6 screws securing the main pcb to the case upper and lift the pcb free,
complete with front and rear panels.
4. To remove the control pcb from the front panel, first pull off the small knobs and unplug
the two flat cable assemblies. Then desolder all other wire connections between main and
control pcbs (at the control board end), lift the assembly clear and undo the 8 screws
which hold the control board to the front panel; the control board can then be removed.
5. To gain access to the microcontroller the LCD must be removed.
6. The rear panel can be removed by undoing the tamper-proof safety earth connection.
7. Reassemble in the reverse order taking care to remake connections exactly as before,
particularly the safety earth wiring.
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