need service mode code for a TV Amstrad 28" 4/3

[ccenta]

Hi, i write from Italy, i've a problem to enter in service mode for this TV

The features of the TV ((bought in summer 2005) are :

(label on back external) TV AMSTRAD 28" 4/3 stereo S/N1 : AU28 PT90 (i'ts PT90 chassis ??!!??)

(label on back external)S/N2 : 20050228284071435195725

tube samsung a66qew13x49 04167 (18-01-05)

3 chip : STV2246H , MICRONAS MSP3400G , ST92195C781/MIF

electronic tube :28al (1t) line c
samsung shem dnf28
lnc 041122

Selector : Samsung

I need the code to enter in service mode, thanks
I thought code 1923 could be ok, but don't work !

I've more photos of this chassis if you need it