Koji, I didnt realize you were in spain. Have patience Donna and Kitk can get backed up and they will help but I would e-mail or call again. If you hear the pump upon start up and then it shuts off that indicates the vacuum switch is working which means there is a vacuum. If the pump did not shut off this would indicate a leaky hose. Put a record on the platter and clamp it firmly suck on the hose and see if the lip starts to pull down, plug it with your tongue and see if it holds vacuum if so your platter is ok and now to the fittings and pump itself. I dont agree that the vacuum does little or nothing. On a perfectly flat record the difference will be minimal if at all noticeable but if there is even a slight warp you will hear an audible improvement. I like the way records sound on my sota better than any table Ive owned and I attribute some of that to the vacuum. From your picture it looks like you have the current lip on the platter which is great and may indicate the decks been updated.
good luck, Rick
good luck, Rick