Платёжный терминал то и дело показывает ошибку.

То и дело is an idiomatic expression meaning constantly, repeatedly, again and again, or every now and then depending on context.

In this sentence, it gives the idea that the payment terminal keeps showing an error over and over.

So:

• Платёжный терминал показывает ошибку = The payment terminal shows an error
• Платёжный терминал то и дело показывает ошибку = The payment terminal keeps showing an error

It is a fixed expression, so it is best learned as one chunk.

Because ошибку is the direct object of показывает.

The verb показывать means to show, and what is being shown? ошибку = an error.

The dictionary form is:

• ошибка = error

But in the accusative singular, it becomes:

• ошибку

This happens because ошибка is a feminine noun ending in -а, and feminine nouns of this type usually change -а to -у in the accusative singular.

The imperfective verb показывает is used because the sentence describes a repeated, ongoing situation, not a single completed event.

Compare:

• показывает = is showing / shows / keeps showing
• показал = showed once
• покажет = will show

Since то и дело already suggests repetition, the imperfective fits very naturally:

• то и дело показывает ошибку = keeps showing an error

If you used a perfective form, it would not match the idea of repeated behavior as well.

Платёжный терминал means payment terminal.

It usually refers to a machine or device used for payments, such as:

• a self-service payment kiosk
• a card terminal
• a payment machine in a store or public place

The adjective платёжный comes from платёж meaning payment.

So literally:

• платёжный = payment-related
• терминал = terminal

Together: payment terminal

They are the same word. The difference is only in writing:

• платёжный = with ё
• платежный = with е instead of ё

In standard pronunciation, the sound is ё, but in everyday Russian writing, ё is often replaced by е. So you will frequently see платежный терминал in real texts, even though платёжный shows the pronunciation more clearly.

For learners, seeing ё is very helpful.

Yes, this is natural Russian. A machine, app, or device can:

• показывать ошибку = show an error
• выдавать ошибку = give an error / throw an error
• сообщать об ошибке = report an error

All of these are possible, but they differ slightly in tone:

• показывает ошибку sounds straightforward and common
• выдаёт ошибку often sounds a bit more technical or colloquial when talking about devices/software
• сообщает об ошибке sounds slightly more formal

So this sentence is perfectly natural.

Yes, absolutely.

• Платёжный терминал то и дело показывает ошибку.
• Платёжный терминал то и дело выдаёт ошибку.

Both are natural.

A small nuance:

• показывает ошибку focuses on what appears on the screen
• выдаёт ошибку often means the system produces an error message or fails in some technical way

In many everyday contexts, the difference is small.

Yes. Russian word order is flexible, though the neutral order here is very natural:

• Платёжный терминал то и дело показывает ошибку.

You could also say:

• Платёжный терминал показывает ошибку то и дело.

This still means basically the same thing, but it sounds a little less neutral and gives slightly different emphasis.

Russian word order often changes the focus rather than the core meaning. In a basic learner context, the original order is the safest one to use.

It suggests repeated annoyance, not necessarily nonstop failure every second.

То и дело usually means something like:

• repeatedly
• often
• again and again

So the idea is that the terminal keeps showing an error whenever someone tries to use it, or very frequently during a period of time.

It does not have to mean literally uninterrupted action. It means the problem happens often enough to be noticeable and frustrating.

Russian has no articles like a or the.

So:

• Платёжный терминал can mean a payment terminal or the payment terminal
• ошибку can mean an error or the error

The exact meaning depends on context.

In this sentence, English might translate it as either:

• The payment terminal keeps showing an error
• A payment terminal keeps showing an error

Usually, context tells you which one is meant.

Yes, it is neutral and natural everyday Russian.

It is suitable in normal speech and writing when talking about a machine malfunctioning. The only slightly expressive part is то и дело, which adds a sense of repeated irritation, but it is still very common and not overly dramatic.

So the sentence sounds like ordinary, idiomatic Russian.