Electric BED Main Control Box (CRAFTMATIC)

The problem is  the Top head actuator motor goes up, but does not go down.

all other control and motors are working fine.

- The remote and the wire have been replaced so I do not suspect this part.

- I switch bottom and  top actuator on the card and both actuator are working fine.

I replaced the 2 Triacs and the 2 MOC 3042s (the first on the right after the transformer)

Does somebody could help me troubleshoot this ?

Thanks a lot