开云体育

Hi Pavel--
on your 2nd pic of the underside you can see 2 tabs in the center of the middle brackets where you are missing a spring.? the spring keeps the back bracket raise to lock the newly selected button in place but release the previously pressed button - so push in button, pushed bracket back which releases any other button selection but then pops pack up to "grab" the one you're pressing.??

on the vacuum valve itself, looks like you might be missing a locking screw if i recall,? i have a spare one of these somewhere that should still show the lock on the valve, i think.? there were some posts on OWF as well i believe on refurbish these way back and I think on here in the knowledgebase if it migrated.
greg