How to Repair the Dollar Reader on a Vending Machine

By Elizabeth Falwell

Updated September 26, 2017

A dirty or clogged dollar bill reader on a vending machine could cause it not to accept cash.
i Cate Gillon/Getty Images News/Getty Images

Vending machines can accept paper money, coins and even credit or debit cards. If the dollar bill reader on your vending machine becomes dirty or clogged, it can stop working. While vending machines should only be repaired by the service company--the company that provides maintenance and fills the vending machine with goods--there are steps you can take to fix the dollar reader on your own before calling in the pros.

Examine the dollar bill slot; you might want to use a flashlight to help you see better. Look for dirt, debris or other items that could be blocking the slot. Remove any obvious debris with your fingertips.

Insert a dollar bill into the reader to test it. If you are now able to make a purchase, you have fixed the problem.

Probe more deeply into the dollar reader slot by using a cotton swab. While you can use a generic cotton swab, the vending machine repair website (see References) recommends using elongated cotton swabs with a wooden handle. These longer swab sticks will give you better access to the parts of the dollar reader that are too small for you to reach by hand. Using a flashlight, illuminate the dollar reader slot and remove as much dirt or debris as possible with the swab.

Test the dollar reader again. If you can make your purchase without any problems, you have fixed the issue.

Insert a dollar bill reader cleaning card into the slot. The website (see References) suggests inserting the card into the slot; the end with the black strip on it should go in first. Push the card into the slot, then wait for the reader to push it back out. Repeat this three times. This will clean the belts and rollers used to grasp and accept a bill into the slot of any lingering dirt.

Insert an actual dollar bill into the slot to see if the cleaning card did its job. If your bill is accepted and you can make a purchase, the problem has been fixed.

Items you will need

  • Flashlight

  • Cotton swabs

  • Cleaning card

  • Dollar bill


Call the company contracted to maintain and load your vending machine if the basic repairs to clean the dollar bill reader do not work. In most instances, vending machines are owned and maintained by an outside company.


Do not attempt to perform any further repairs--such as taking the bill reader apart--unless you are the owner of the vending machine.