Yeah sir like u said the holtek mcu must be faulty bcoz it doesnt give the necessary voltage and command to the 5 couple pins where the buttons connected bu . It just gives 2,48 V to one of those 5 couple pins and it is the one that works now . See the picture

just button number 3 works , number 1 ,2 and lamp button doesnt work,
Thanks again

 

Are the buttons and 7 segment display mounted on a printed circuit board ? If so can it be removed to be photographed ?

Les.

 

Are the buttons and 7 segment display mounted on a printed circuit board ? If so can it be removed to be photographed ?

Les.

I will take a photo of circuit board of the buttons when I get home. , but like @Dodgydave suggested I think the IC holtec processor is faulty bcoz all the the pins connected to the buttons have zero voltage except the second one has 2,48 V dc . see the picture plz.
In my view , the faulty holtec processor doesnt send the necessary commands to other four pins , a I made a continuity test from buttons pcb to the connector at the end of the buttons cable, there is no problem, we have continuity there.