[giampiero]

Citimarine.com has replacement boards for legacy Marine Air Systems, Cruiseair and Dometic. As previous post mentioned you will need make and model number. You may also need to give them some information on your thermostat, depending on which unit you have as many boards require a specific model of thermostat.

many thanks for your - and donaldjames - replies,
here are the details of the a/c on the containing box (anyway photos of the mother board are also available):

• Marine Air Systems / manufactered by Dometic
  
• product # : 201 - 411160
  
• s/n # : 62456965
  
• model # : CSD6KZ50/1 - 41710PVBX 
  
• shop order: 078642
  
• cap. (BTU) 6000
  
• voltage/hertz 220-240/50
  
• PH 1
  
• max fuse 10
  
• min fuse 7
  
• FLA.COOL 4.1
  
• FLA HEAT 4.8
  

Elec. data above based on 220/50 HZ
I.O. control; 417 Refrigerant; 
10' Plug Harness
Vertical Electrical Box