PC Boards - EPROMS

Automatic Products 113/112 PC Board (Refurbished)

$149.00
AP 123/122/121 (MDB) PC Board (360274) (Refurbished)

$299.00

Vending Machine PC Boards and EPROMs

Find replacement vending machine control boards and EPROM chips for selected snack and soda machines. A control board helps the machine read selections, manage vend cycles, communicate with payment equipment, and report errors. An EPROM stores program information used by compatible control systems. Choosing the correct part starts with the exact machine model, board number, and software version.

Vending World lists refurbished PC boards and selected EPROMs for Automatic Products, Dixie-Narco, National Vendors, Royal Vendors, and Vendo Sanden equipment. Browse the product listings above to see current prices, stock status, and the details for each item.

Electrical safety: Switch off and disconnect machine power before touching a board or connector. Follow the machine service manual. Do not reconnect power until every plug is seated correctly. If you are not trained to work around electrical equipment, use a qualified vending service technician.

Find the Right Electronic Part

1. Identify

Record the manufacturer, model, and serial number.

2. Compare

Match board markings, part numbers, and connector layout.

3. Confirm

Check EPROM version and payment-system requirements.

4. Install

Follow safe replacement and programming steps.

Control Boards and EPROMs in This Category

Manufacturer	Listed part	Important matching detail
Automatic Products	112/113 refurbished PC board	Check the exact board revision and machine configuration.
Automatic Products	121/122/123 MDB board, part 360274	Confirm the board number and MDB setup.
Dixie-Narco	5591 MDB control board	Verify 5591 configuration and board revision.
Dixie-Narco	S2D-E board, part 804911880.01	Listed for selected 276E, 501E, and 600E applications; confirm reader compatibility.
National Vendors	147 PC board and 147 interface board	These are different parts; identify which board is faulty.
National Vendors	157/158/167/168 control board	Confirm model and programming requirements.
National Vendors	157 interface board	Do not confuse an interface board with the main controller.
Royal Vendors	G111 control board	Match the original board and machine setup.
Vendo Sanden	Univendor 2 board 5.1	Listing names models 480, 511, 570, and 601; check availability.
Vendo Sanden	V-Max late-style board 9.1	Listing names models 540, 576, 720, 630, and 840.
Dixie-Narco	S2D EPROM	Check the S2D board and firmware marking.
National Vendors	158 EPROM	Match the 158 program version.
Vendo Sanden	9.1 EPROM	Match the supported V-Max board version.

Important: The names above describe items shown in the category at the time of review. A model name in a listing is not a guarantee that every machine revision accepts the part. Product availability can change.

What a Vending Machine Control Board Does

The control board is a central part of many electronic vending machines. It reads input from buttons and other controls. It also sends commands to motors, displays, and supported payment devices. Its exact tasks depend on the machine design.

Reads customer selections and service-menu inputs
Checks conditions before starting a vend
Sends commands to selected motors or vend mechanisms
Stores or uses prices and operating settings
Works with compatible coin mechanisms and bill validators
Shows status messages and service errors when supported

How an EPROM Differs from a PC Board

A PC board is the physical electronic assembly. An EPROM is a memory chip that may be installed on a compatible board. The chip holds program instructions or data used by the controller. Not every board uses a removable EPROM.

A replacement EPROM does not fix damaged board traces or failed components
A replacement board may still need the correct program version
EPROM labels and revision markings matter
Chip orientation must match the socket and service manual
Do not force a chip into a socket
Confirm whether programming and setup are needed after installation

Why Exact Compatibility Matters

Machines that look similar from the outside may use different electronics. Manufacturers revise control systems over time. A board with a similar shape or connector may still be the wrong part.

Compare full part numbers, not just the machine name
Check serial-number ranges in the service documentation
Inspect connector count, shape, and position
Check voltage and payment interface requirements
Verify display and keypad support
Confirm software or EPROM version before ordering

Refurbished Control Boards

A refurbished board can be a practical choice when an original replacement is hard to find. The category identifies many listed boards as refurbished. Review each listing for its specific condition and warranty details.

Inspect the product listing and images
Ask about exact revision matching when uncertain
Do not assume a refurbished board includes an EPROM
Keep the original board until the repair is complete
Use a clean, dry work area
Save your machine settings before changing hardware when possible

Before You Order a Board

Good identification helps avoid delays and return shipping. Take clear photos before removing any electronics. Record all labels and the way connectors are attached.

Machine brand and full model number
Serial number and manufacturing information
Part number printed on the original board
Any sticker or EPROM revision number
Payment system type and interface
A short description of the fault and any displayed error

Safe Board Removal

Electronic boards are sensitive to power and static discharge. Work only when the machine is safely disconnected. Capacitors and other electrical parts may retain hazardous energy even after power is removed.

Follow the machine-specific service manual
Disconnect power and verify a safe condition
Use proper electrostatic discharge precautions
Photograph each connector before removal
Release locking tabs rather than pulling on wires
Protect the removed board from moisture and physical damage

Safe Board Installation

A replacement board should be mounted securely and connected exactly as required. Wrong connections can damage electronic parts. Never guess where a plug belongs.

Confirm the replacement part number once more
Inspect for bent pins, loose terminals, and damaged insulation
Seat connectors without forcing them
Secure mounting hardware and insulating supports
Check that no loose screws remain in the cabinet
Restore power only after completing all checks

After Installation

A new or refurbished controller may need setup before normal operation. The exact steps vary by model. Consult the service manual for pricing, motor mapping, and payment settings.

Check the display or startup message
Review stored prices and selection assignments
Check payment device communication
Test vend functions according to the manual
Review errors after test vending
Record the board revision and date of replacement

When the Board Is Not the Problem

A blank display or failed vend does not always mean the main control board has failed. Power supplies, connectors, switches, motors, and payment devices can create similar symptoms.

Inspect fuses and power connections safely
Look for damaged or loose harnesses
Check whether the keypad is responding
Check motor or vend mechanism obstructions
Review payment-device status and cabling
Use error codes and service procedures to isolate the fault

Avoiding Repeat Failures

Finding the original cause of a failure is important. A shorted motor, damaged cable, or moisture leak can harm a replacement board too.

Repair damaged wiring before installing the replacement
Keep moisture away from electronics
Correct loose connections and corrosion
Use only approved replacement parts
Do not bypass protective devices
Investigate repeated blown fuses or unusual odors

Working with Older Machines

Older snack and soda machines can remain useful when compatible service parts are available. Their electronics may differ from newer models in connectors, firmware, and payment support.

Keep model-specific service manuals
Maintain a record of board versions
Label stored spare parts clearly
Check payment upgrades against controller capability
Test repaired machines before returning them to service
Plan for parts that may have limited stock

Understanding Payment Interfaces

Some boards are described as MDB-capable. MDB is a communication standard used by many vending payment devices. The board, harness, firmware, and peripherals must all support the intended setup.

Do not assume every board supports every card reader
Verify MDB wiring and power requirements
Check machine firmware and payment configuration
Confirm coin and bill device compatibility
Review cashless reader requirements separately
Test transactions with the machine safely assembled

Understanding Interface Boards

An interface board may connect signals between a main controller and other machine systems. It is not always interchangeable with the main control board.

Identify which physical board is being replaced
Match printed part numbers and board revisions
Check connected harnesses and sockets
Do not order by visual similarity alone
Review machine-specific diagnostic instructions
Confirm whether the board is sold separately

Understanding Board Revisions

A version number may refer to hardware, firmware, or a family of boards. A higher number is not automatically a drop-in upgrade.

Read every printed and stickered revision
Compare the board to the manufacturer documentation
Check whether an EPROM swap is required
Confirm that connector assignments are unchanged
Review any required setup changes
Ask for help before ordering an uncertain revision

Storage and Handling

Electronic parts last longer when stored carefully. Keep spare boards away from dust, liquid, and uncontrolled static.

Use anti-static packaging where appropriate
Store parts in a clean, dry cabinet
Avoid crushing connectors or components
Label the machine model and part number
Keep EPROMs protected from bent pins
Do not store loose metal hardware with boards

Maintaining a Service Record

A short repair log can save time on future visits. It helps identify repeat problems and prevents confusion between similar machines.

Record the site and machine ID
Write down the fault before repair
Keep photos of original wiring
Record the replacement board number
Note any settings that changed
Log the result of test vends and payment tests

Model-by-Model Buying and Repair Guide

Use these notes to narrow your search. They are general buying guidance, not a substitute for the manufacturer service manual.

Automatic Products 112 and 113

The 112/113 listing is for a refurbished Automatic Products PC board. Check the exact control-board version, the snack machine configuration, and the existing wiring before making a purchase.

Check before buying: Do not assume that a board from a different Automatic Products series is interchangeable.

Automatic Products 121, 122, and 123

The AP 121/122/123 MDB board listing identifies part number 360274. Match that number with the installed part. Review payment communication, selection setup, and any program requirements.

Check before buying: MDB support on a board does not by itself prove compatibility with a particular cashless reader.

Dixie-Narco 5591

The 5591 MDB control board serves a specific Dixie-Narco platform. Confirm the original board label, machine version, and supported payment configuration before ordering.

Check before buying: A 5591 board should not be selected only because the machine has a glass front.

Dixie-Narco S2D-E

The S2D-E listing names selected Dixie-Narco 276E, 501E, and 600E machines and part 804911880.01. Check the board revision and all other stated conditions for your unit.

Check before buying: The phrase credit-card-reader capable requires checking the full reader, harness, and firmware combination.

National Vendors 147

The National 147 main PC board and 147 interface board appear as separate listings. Identify which part has failed before ordering.

Check before buying: Replacing the interface board may not resolve a fault caused by the main controller.

National Vendors 157, 158, 167, and 168

A refurbished control board is listed for these National Vendors model families. Check exact model and version details because one machine family can have different configurations.

Check before buying: Confirm programming and any removable EPROM requirements.

National Vendors 157 Interface Board

This separate interface-board listing may help when the main controller is working but a connected subsystem has a verified interface fault. Use model-specific diagnostics.

Check before buying: Do not replace the interface board based only on a blank display or failed vend.

Royal Vendors G111

The Royal G111 refurbished control board should be matched by its full markings and the machine service information. Check harness layout and supported configuration.

Check before buying: Royal Vendors machines are not all equipped with the same controller.

Vendo Univendor 2 Version 5.1

The listed Univendor 2 board 5.1 names models 480, 511, 570, and 601. Availability may vary. Confirm the installed hardware version and machine documentation.

Check before buying: A model match alone does not confirm the correct software setup.

Vendo V-Max Late-Style Version 9.1

The late-style V-Max 9.1 listing names models 540, 576, 720, 630, and 840. Check the board version and any associated EPROM requirements.

Check before buying: Late-style and early-style boards should not be assumed interchangeable.

Dixie-Narco S2D EPROM

The S2D EPROM is a program component for specified S2D boards. Compare chip labels and confirm the target controller before handling the chip.

Check before buying: An EPROM does not replace damaged power or motor circuitry.

National 158 EPROM

The National 158 EPROM listing references version 158.29. Confirm the correct program for the machine and board revision.

Check before buying: Never install an unknown EPROM solely because it fits the socket.

Vendo 9.1 EPROM

The Vendo 9.1 EPROM listing identifies a V-Max application. Compare the exact board and chip markings before purchase.

Check before buying: Check chip orientation and follow approved ESD handling procedures.

Frequently Asked Questions About Vending Machine Boards

Can I use a control board from a different vending machine model?

Only when the manufacturer documentation and part specifications confirm compatibility. Similar appearance is not enough.

What does refurbished mean?

It describes a previously used item that has undergone refurbishment. Check the individual product listing for the stated condition and coverage.

Will a replacement board fix a machine that does not power on?

Not necessarily. A supply, fuse, switch, wiring problem, or other electrical fault may prevent startup.

Do I need to replace the EPROM with the board?

It depends on the board, the supplied components, and the required program version. Confirm what is included.

What information should I send before ordering?

Send the machine model, serial number, board part number, version markings, and clear photos of both sides when safe to obtain.

Can a control board work with a card reader?

Some systems can. Confirm the payment interface, harness, firmware, and reader requirements.

Why does a machine show an error after a board swap?

A wrong board, loose connector, missing setup, or another machine fault may be responsible. Follow the model service diagnostics.

What should I do if the replacement does not work?

Disconnect power safely, review the connections and part number, and follow the seller’s published return or warranty process.

Can I change an EPROM while the machine is on?

No. Disconnect power and follow the manufacturer procedure. Handle the chip with appropriate anti-static precautions.

Is a board with a newer revision always better?

No. Revision changes can affect connectors, features, and firmware compatibility.

Should I save my settings before replacement?

Yes, where possible. Record prices, selections, and configuration values so they can be restored if needed.

Can moisture cause board problems?

Yes. Moisture and corrosion can damage electronic assemblies and connectors. Find and correct the source before replacement.

What if a new board fails again?

Investigate the connected loads, wiring, power supply, and environmental conditions before fitting another board.

Is an interface board the same as the main PC board?

No. They may perform different functions and are listed as different parts.

Where can I find the part number?

Look for labels, printed numbers, or markings on the board. Use the service manual to interpret them.

Can I install a board myself?

Only if you have the skills to work safely with electrical equipment and can follow the correct service instructions. Otherwise hire a technician.

Symptom-Based Troubleshooting Reference

Use this chart to decide what to inspect before buying a replacement board. These are starting points, not live electrical test instructions.

Symptom	What to review	Why it matters
Blank display	Check incoming power, power supply, fuse condition, display harness, and board connectors.	A dark screen alone does not prove the main controller is defective.
Buttons do not respond	Inspect the keypad membrane, connector, and interface circuit.	A keypad or cable problem may mimic a board failure.
Motor does not turn	Check for jams, motor wiring, selection setup, and applicable motor diagnostics.	A failed motor can damage connected electronics.
Machine accepts money but will not vend	Review prices, credit reporting, vend interlocks, and mechanical obstructions.	The controller may be responding correctly to another fault.
Bill validator not detected	Check device power, harness type, communication settings, and device status.	MDB and other interface types are not interchangeable.
Coin mechanism not detected	Inspect the correct cable, interface, and coin device diagnostics.	Do not assume the controller is the cause.
Cashless reader not communicating	Verify controller capability, firmware, MDB setup, harness, and reader power.	A compatible reader may still require additional setup.
Machine vends wrong selection	Check motor mapping, selection configuration, and harness placement.	Settings may have been lost during a board change.
Repeated error after startup	Write down the full error and consult the machine manual.	Different models can use the same error number differently.
Intermittent resets	Inspect stable supply voltage, loose terminals, moisture, and affected devices.	Repeated resets may be a power issue.
Display works but no credit appears	Check payment devices, configuration, and communication.	The display working does not prove all controller functions work.
A new EPROM is not recognized	Check chip type, orientation, version, and socket condition.	Do not force the chip or keep powering a suspect installation.

Practical Guides for Operators and Repair Technicians

Ordering for a single machine

When one machine is down, focus on an exact match rather than a broad replacement. Record the original part number and the visible fault. A short list of verified details can save a second service visit.

Before checkout: Compare the machine model, board version, EPROM label, and product listing. If any detail differs, resolve it first.
After delivery: Inspect the package and compare the received board with the original before removing protective packaging.

Ordering for a vending route

Operators with several machines can reduce delays by keeping a clear equipment list. Similar cabinets can hide different electronics. Treat every serial-number group as a separate configuration until verified.

Before checkout: Group parts by confirmed board number, not by location or machine color. Keep a record of which models share an approved replacement.
After delivery: Label spare boards and keep them in protected packaging until needed.

Planning a service visit

Good preparation limits machine downtime. Bring the machine documentation and a safe method to record connector positions. Know which checks require a qualified technician.

Before checkout: Confirm whether the symptom points to the board, an interface, an EPROM, or another device.
After delivery: Test the repair in a controlled way and record the results before leaving the site.

Comparing a main board and interface board

These components can look related but serve different jobs. A main controller coordinates machine operation. An interface board may route signals or connect another subsystem.

Before checkout: Identify the exact failed assembly using the manual and part labels.
After delivery: Replace only the verified component and inspect its connected harness.

Considering a firmware or EPROM change

A firmware change should have a clear purpose, such as restoring a specified program version. A chip swap is not a general repair for unrelated electrical damage.

Before checkout: Confirm the required program number and whether the chip is compatible with the installed board.
After delivery: Follow the approved procedure, then check machine settings and operation.

Restoring prices and selections

Control board replacement can affect stored settings. The steps for setup depend on the controller and machine. Record existing prices whenever possible.

Before checkout: Find the correct programming manual and note how to enter service mode.
After delivery: Verify each selection and price with test procedures approved for the machine.

Checking payment readiness

Payment upgrades involve more than a single board. Readers, validators, coin mechanisms, wiring, and software must communicate correctly.

Before checkout: Check the full set of compatibility requirements for the chosen payment devices.
After delivery: Confirm credit display, approved transaction behavior, and vend completion.

Investigating repeat board damage

A second board failure suggests that another cause may remain. Damaged harnesses, liquid leaks, or faulty loads can affect new electronics.

Before checkout: Arrange diagnosis of the underlying cause rather than buying repeated boards without testing.
After delivery: Correct the source of damage and document the fix.

Preparing for seasonal maintenance

Preventive checks can reduce unexpected service calls. Electronics benefit from a clean, dry cabinet and sound wiring.

Before checkout: Review which spare parts are actually compatible with your route.
After delivery: Keep spares protected and inspect the machine during scheduled visits.

Choosing parts for older machines

Older equipment may use hardware and software revisions that are no longer common. A clear photo of the original part is often useful.

Before checkout: Check the exact board number, connector style, and program label.
After delivery: Keep a record of the replacement and retain service documentation.

Reviewing return and warranty terms

Electronic parts often have specific handling and return rules. Read the current policy before purchase.

Before checkout: Confirm whether the item is refurbished, what is included, and which warranty or exchange terms apply.
After delivery: Inspect promptly, follow installation rules, and contact the seller through the stated process if there is a problem.

Reducing unnecessary parts purchases

Troubleshooting before ordering helps prevent replacing a working controller. A power fault, jam, or bad connector may produce the same symptom.

Before checkout: Use model-specific error codes and diagnostic procedures to isolate the issue.
After delivery: Verify that the replacement actually resolves the original symptom.

Detailed Inspection Checklists

The following checklists help you organize a service call. They do not replace qualified electrical diagnosis or the instructions for your machine.