Introduction; Purpose Of This Manual; Esd - Electrostatic Discharge And Its Effect On The Components; General Description - Electrolux Hob Service Manual

1.

INTRODUCTION

1.1 PURPOSE OF THIS MANUAL

The purpose of this Manual is to provide technical details regarding the new control system for
built-in gas hobs so that trouble-shooting and repairs cab be carried out correctly.

1.2 ESD - Electrostatic Discharge and its effect on the components

The interface for the control unit is not fitted with an internal device to protect against electrostatic
discharge (multiple connectors). When effecting repairs, therefore, the service engineer must
check for stabilization of the potential on the oven casing (i.e. discharge any static electricity by
touching the oven casing) in order to prevent the possibility of overload, which might damage the
control unit.
The same care is necessary when handling control units supplied as spare parts (i.e. not yet fitted
to the oven), which must be removed from the protective bag in ESD only after stabilizing the
potential (i.e. discharging any static electricity) and only then installed in the appliance.
Important: The theory behind the process of electrostatic charge and discharge is not discussed in
this Manual, since the tangible effects are considered to be more important. However, the effects
are felt frequently when touching a metal handle and feeling the electrostatic discharge in the form
of a minor shock.
But what happens when stabilization of the potential takes place with semi-conductor components
(i.e. components on a circuit board, such as integrated circuits, microprocessors etc.)?
Stabilization of the potential takes place across the internal structure of the component. This does
not necessarily lead to the immediate destruction of the component; subsequent malfunctions
across damaged internal connections may be more harmful, and these occur only as a result of
overheating or current overloads.
It is true that almost all sensitive semi-conductor components (such as MOS circuits) have been
improved by the addition of protective measures, but the internal structures of these components
are today smaller than, for example, ten years ago, which tends to increase their sensitivity to the
previous levels.
Important!
Which components are susceptible to damage by static electricity during repairs?
All circuit boards featuring control and command accesses (door switches, food probes etc.), bare
tracks and microprocessors, as well as any other circuits with free access.
Examples:
- Programmers with access to the food probe and the door switch.
- Programmers whose control processors are accessible (due to their high costs, the protective
systems are only partial).
- W.O.E.C. control units.
- S.O.E.C. control units.
- C.H.E.C. control units.
- KRONOS control units.
- Interface board of the Electronic gas hob.

1.3 GENERAL DESCRIPTION

In these hobs, the burners are controlled entirely by a special electronic system that actions special
solenoid valves which regulate the quantity of gas delivered to the burners.
With the introduction of this electronic control system, it is now possible to fit Touch Control keys,
as well as to provide greater safety, such as automatic re-lighting of the burners, and several
control functions, including indication of residual heat, child safety feature, interruption of all
operations using a single switch, safety cut-off in case of power failure or failure to light, automatic
timer-controlled switching off and programmed operation of the burners. These functions are
described in this manual.
SOI 04.05 FV 6/57 599 36 62-62