powermax installation code

["Scorpio" <Nada@xxxx>]

Help please.

I have just bought a used powermax burglar alarm system.
I can change al the codes and al works fine.\
But I had already the same visonic and it broke so this one must "learn"my
old detectors.
This is done in the installation menu.
To get ther you must have a code.default is 8888 or 9999
but a mechanic changed it when installing it at previous owner , so he
doesn't know it .
How to "reset "it ??????????????????

Thanx in advance