what does "replace a validator" mean in pc repair?

[MoneyDukes]

I was recently looking for work and found this as the job description:
The responsibilities are to cover the territory assigned and to perform basic break/fix duties (replace a Validator, re-image a workstation, replace a PC etc.).

I have no idea what replace a Validator means. I have done pc repair for a while and I would like to apply for this job. Can anyone provide me with details of what this means?

 

[baltman]

Popular job.

Google Search

I'd guess a process to identify and correct problems.

Brian