Repair of Necta Main Board 6735-556-02 - Canto, Concerto, Festival, Opera, Samba

Fast and effective repair of the main board in elegant Necta vending machines with graphic displays.

Necta CPU 6735-556-02

Photo of a Necta main board 6735-556-02

The Necta main board with designation 6735-556-02 (sometimes denoted as 6735/556/02) is the core control module in many mid- and high-range models from Necta and N&W Global Vending. Unlike older boards, it works with several modern, elegant graphic displays.

Necta machine models where this board is commonly found

  • Canto
  • Concerto
  • Festival
  • Melodia
  • Opera
  • Rock
  • Samba Top
  • Samba Classic
  • Tango

Most common faults of Necta main board 6735-556-02

  • The board does not start at all (no response after powering on)
  • Incorrect motor control (machine spins multiple spirals at once or does not see the shelf/column)
  • No communication with the coin validator
  • No information on the display (black screen or no backlight)
  • Freezes during photocell test
  • Keyboard doesn’t respond

Unusual fault (frequently caused by users)

Sometimes users confuse connectors and insert the upkey into the keyboard socket by mistake. This very often causes serious damage to the board (burning multiple integrated circuits). In such case - you have to replace the card.

How to diagnose Necta main board 6735-556-02

  • Check if the green LED is lit. If not → verify power supply to the board on the three-pin green connector. It should be 24VAC. If power is present but the LED is off → board fault.
  • Red LED is lit → board fault.
  • Disconnect the display ribbon cable - if the red LED turns off and the green one starts blinking → board fault.
  • (Spiral machines) Check how many motors the board detects during startup. Does it match the actual number? If not → board fault:
    • Check if any wiring harnesses are worn or damaged (often caught in shelf guides)
    • Check if the motor pins for the spirals are not touching the metal rear wall and are properly insulated
      NOTE: This check is extremely important! Customers often send us boards without fixing the harness short circuit, and the board fails again shortly after repair (not covered by warranty).
  • (Spiral machines) The board detects no motors at all → board fault.
  • (Spiral machines) The board freezes during photocell test → board fault.
  • Coin validator not working: check payment system settings. If incorrect → backup battery is likely dead and machine boots with defaults. If correct and you have a payment system → check MDB/Executive settings. If correct → disconnect payment system and connect coin mechanism directly to the board connector - if still no “no change” → board fault.
  • The board does not remember prices or validator parameters → worn backup battery.

Price and turnaround time

Price : 93 EUR net

Turnaround time : 5 working days

Description : Standard repair for most boards (CPU, actuator, hub board)

The quoted price and turnaround time are estimates. In rare, unusual cases, we will agree on the conditions with you beforehand.

How to prepare and send the board for repair

  1. Label the package
    Clearly write on the box: “ELECTRONICS FOR REPAIR - VENDFix.eu”

  2. Describe the faults
    Attach a note to each board with the problem description (defines diagnostic scope)

  3. Include invoicing and return shipping details

    • Company name / full name
    • Full address (including postal code and city)
    • VAT number (if company)
    • Phone number and email

  4. Send to:

    VENDFix
    Techniline sp. z o. o.
    Sosnowa 4
    26652 Janiszew
    Poland
    tel. +48 696-42-10-42

Ready to send your Necta 6735-556-02 main board?

Contact us

Good luck with your machines!