How to Repair Troubleshoot Vending Machine

Introduction To Basic Vending Machine Troubleshooting and Repair

I think i have been doing this vending machine business for quite a bit of time already.

I would like to share with you the basics on repair and troubleshooting vending machine basics. Its pretty straightforward and simple. This simple tutorial will cover the essential and basic repair skills that you need in order to operate you’re vending machine business without any setback and problems.

This is for all the folks that are not electronically and mechanically inclined in fixing vending machines.

I will categorize into several things that you are targeting since 95% of the problems can be solved just by following the steps and procedures.


You will have noticed that you have several common types of machines :

  • Standalone Snack Machine
  • Standalone Pop Machine
  • Combination Snack and Pop Machine
  • Glass Front Pop Machine

Basic components inside the vending machines

For the longest time that you have been refilling, opening and closing you’re vending machines. There are basically basic components that is obvious which are as follows :

Mainboard or Control Board

This is the motherboard of the vending machine where there is a CPU and EEPROM that contains all the necessary programs and algorithms that in which it essentially controls the motors, counts, vends, transactions, temperature and all the necessary functions of the vending machine



This is a very obvious component that is attached to the main board wherein a user inputs the product selection. This keypad is also used for diagnosis and tests procedures for the vending operator.

This can be compared to the keyboard of the laptop or computer

Coin Mechanism or Coin Mech for short

This is an essential component that needs to be cleaned all the time, because this is the component that captures all the coins inserted into the vending machine. This is actually the guy who is accepting all those coins and sorts it inside and decides if it is a real or fake coin.

Most of the problems that happens is when the customer inserts a coin that is not Canadian it will jam and render the vending machine out of order or unable to accept coins.

The coin mech is basically the same of all vending machines and same for all countries.

The only difference between a foreign coin mech and Canadian coin is that difference countries have different design in the coin chute where it takes certain size, weight and dimensions.

For the coin mechs in Canada, the coin chute is designed in a way that it only accepts Canadian coins and there is a small magnetic sensor that will detect the correct metallic composition of the coin and verifies it and will make a handshake with the control board and says it received a toonie or loonie for instance.

The coin mech is a critical component.

Make sure that you always use a damp cloth to clean the coin path every month making sure it is clean.

Make sure that you have plenty of change so that the machine can accept dollar bills ensuring that you have consistent sales.

Always test the coin mech with coins before leaving the location and press coin return to ensure that everything is in order.

By the way there is a very helpful you tube video on how the coin mechanism works.

Bill Validator

This is the component that accepts the bills form of payments.

Make sure the path of the bill acceptor is clean especially the optic sensors where it detects the different bill denominations.

You can buy a small air can spray from Canadian tire store and just to blow out small debris, lint and dirt that may have accumulated on the bill validator path.

You will notice that the bill validator has some rubber on the sides that looks like a battle tank wrap around tire, at times you can buy acetone and just make a dab and rub it off with a lint free cloth so that it will retain its sticky properties in order to accept the bill properly.

As long as you regularly clean the rubber sides on the dollar validator you will have a long service life.

Here is a You Tube Link on how to clean your dollar bill validator

Priming POP Beverage Vending Machine

Sometimes you will encounter that some of your pop vending machine columns are empty. You need to prime it to make sure that it dispenses properly each time a customer depresses the selection.

Priming means that you need to keep on test vend the pop machine until the product is ready to be vended. You have to do this every time the column is out. Because sometimes when you fill an empty column, when customer depresses the selection it will not come out.

By the way sometimes the floor is not level, get a wrench and adjust the height of the legs of the pop machine accordingly.

Cleaning the Refrigeration Unit

If you do not want to buy an expensive air compressor or a portable vacuum cleaner, then you can buy a couple of compressed air cans.

When you are servicing your pop machine or combo machine, you will notice that there are aluminum fins that is partially covered with dirt, debris and sometimes paper.

You can use the compressed air cans to spray a couple of bursts to remove the dirt on the aluminum fins. Or the easiest method is to use a damp cloth and use wipe it off every time you go service the pop and combo machines with refrigeration unit.

If the refrigeration units is clogged all the time then you may have to spend $ 1,000 for a new compressor because it is burned out from not cleaning the vents.

Glass Front Machine

You have to make sure that the prices are correct. There is a manual included with the machine that was sold to you, if not then ask it from the seller or download a PDF from the manufacturers’ website which is normally available.

If you have enough time then try to test vend everything at least maybe 1 every 2 months to make sure that all the selections are working good.

Sometimes the whole top or middle or bottom shelf is not working ? Then normally according to my experience it is just a molex plug that i loose.

Turn off the power of the unit or unplug it from the wall if you are not sure where the power switch is located.

Look for the loose cable or molex plug and re attach it and make sure it is secure and turn back the power.

If the shelf in question still doesn’t work then the main board maybe the culprit.

The glass front machine is very expensive piece of equipment, if there is a 1 800 number, by all means call them for a guided assistance while you are at the location.

In the future in planning to develop this website to be more comprehensive to include all the vending machine repair and troubleshooting manuals uploaded and links to you tube tutorials on basic vending machine repairs.


The steps above are by no means comprehensive. It covers the basic necessary maintenance procedures in order to make sure all you’re vending machines are working properly and efficient.

If you regularly follow the maintenance routine then you will have fewer calls to you’re vending repair guy who normally charges you at times $85 an hour which is very expensive for small vending operators.

I normally get a bill of around $120 to $250 ranging from some spare parts that you can easily fix it yourself.

If you are very careful and have a keen eye on maintenance then a call to you’re vending repair guy will be only once or twice a year when the compressor needs to be changed or if you need to have some Freon charging on your refrigeration unit.