Service manual

ManualsBrandsZanussi ManualsConvection OvenConvection Oven

S 301.01-00 7

95.11

ELECTRONIC SECTION

THE DIFFERENT TYPES OF P.C.B. CARDS

Each oven can have from 2 to 3 electronic cards.

These are divided into two types:

- mother boards, with all inputs

- user interface cards

The mother boards are subdivided into the following catego-

ries:

- POW 1 as used in ISG ovens

- POW 2 as used in ovens with steam generators.

The mother board POW 2 differs from the POW 1 board for

as it features an additional series of level control relays.

The user interface boards are identified by the following

acronyms:

UIA as used in levels L2, L3

UIB as used in level L4, ACTIVE COMBI

KS as used in levels L2 (without meat probe)

PRB as used in levels L3, L4, ACTIVE COMBI

(with meat probe)

UIC as used in level L6

FSC as used in model ACTIVE COMBI

All P.c.b. cards are fitted with a “POWER FAIL” device,

which stops the cooking cycle during blackouts and contin-

ues, from the point in which it was stopped, when the power

is restored.

How to handle the P.c.b. cards

P.c.b. cards supplied as spare parts are wrapped in protective

anti-shock and antistatic material and should be left in the

protective wrapping until they are to be used.

Caution! When handling the cards, apart from the meas-

ures to be taken in view of preventing their exposure to

electrostatic discharge, the utmost care must be taken in

order to avoid mechanical damage to the cards them-

selves, the components and wiring which must not be bent

and or stretched. Until the card has been installed correctly

particular care must also be taken when handling the

hermetically sealed buttons which are extremely delicate

and sensitive to even light shocks which tend to bend the

actuating pins (see fig.2) This precaution must also be

taken when extracting and inserting the extension caps

which are fitted over the pins.

Due to their high sensitivity to electronic discharge ground-

ing straps must be worn whenever you are working with the

cards or the integrated circuits. The grounding strap pincers

must be attached to the framework of the oven

Fig. 2

which should in turn be earthed. The grounding strap is

available as a spare part with the s.p.n. 02898.

REPLACING P.C.B. CARDS

MOTHER BOARD (Fig. 3)

Foreword

When replacing a mother board the following points should

be taken into consideration:

• The position of the jumper “A” (fig.3) located near the

transformer. This jumper must be inserted between the

contacts X and Y on levels 2 and 3 and the contacts Y and

Z on levels 4 to 6 and ACTIVE COMBI.

• The memory chip “C” which carries the ovens history and

therefore the amount of operational hours and the operational

parameters which have been personalised to the customers

individual requirements by the technician.

• The microprocessor “B” where the operating parameter

reference numbers are stored. The microprocessor has an

individual acronym which identifies the version.

• On level 6 models an ulterior cooking program memory

chip is present. This chip is mounted on the UIC card above

the cooking program display. Should the POWER 2 board

be replaced the cooking program memory will not be lost.

If however the UIC card is replaced the memory chip will

have to be recovered from the old card and mounted on the

new card.

Fig. 3

Legend:

A - Jumper

B - Microprocessor

C - Memory chip

D - Computer interface connection (if required)