El wifi no funciona por un problema técnico.

In Spain, both el wifi and la wifi can be heard, but el wifi is very common and completely natural.

Why the variation? Because wifi is a borrowed word, so speakers do not always assign it the same gender. Many people use el because they treat it like a masculine technology word, similar to el internet or el router. Others use la wifi, sometimes thinking of an underlying feminine noun like la conexión or la red.

For a learner, el wifi is a safe and very common choice in Spain.

Spanish uses funcionar for machines, systems, devices, services, apps, and connections when they work / are working properly.

So:

• El wifi funciona. = The wifi works.
• El wifi no funciona. = The wifi doesn’t work.

You would not normally use trabajar here, because trabajar means to work in the sense of a person doing a job. A machine or service usually funciona, not trabaja.

In Spanish, no normally goes directly before the verb.

So:

• no funciona = does not work

This is the standard word order:

• El wifi no funciona.

Putting no after the verb would be incorrect in normal Spanish.

Here, por means because of / due to.

So:

• por un problema técnico = because of a technical problem

This is a very common use of por to express the cause of something:

• No vine por la lluvia. = I didn’t come because of the rain.
• Se canceló por un error. = It was cancelled because of an error.

Using para would be wrong here, because para usually expresses purpose, destination, or deadline, not cause.

In Spanish, adjectives usually come after the noun.

So:

• problema técnico = technical problem

That is the normal order. English often puts adjectives before nouns, but Spanish usually puts them after:

• un coche rojo = a red car
• una solución fácil = an easy solution
• un problema técnico = a technical problem

Putting técnico before problema would sound unusual here.

It has an accent mark because the stress falls on the té syllable: téc-ni-co.

Without the accent, Spanish spelling rules would lead you to stress it differently. The written accent shows the correct pronunciation.

So:

• técnico = stress on the first syllable

This kind of written accent is very common in Spanish and is an important part of correct spelling.

Yes. That is very natural too, but it means something slightly different in structure.

Compare:

• El wifi no funciona por un problema técnico. = The wifi isn’t working because of a technical problem.
• Hay un problema técnico. = There is a technical problem.

The first sentence talks directly about the wifi not working and gives the reason. The second simply states that a technical problem exists. In real life, both are common.

You can also combine them:

• El wifi no funciona. Hay un problema técnico.

Normally, in a full sentence like this, Spanish would use the article:

• El wifi no funciona.

Leaving out the article sounds incomplete or unnatural in standard Spanish.

That said, in signs, headlines, notes, or very informal messages, people sometimes drop articles:

• Wifi no disponible
• Wifi fuera de servicio

But in normal spoken or written sentences, el wifi is the best choice.

In Spain, many people pronounce it in a Spanish-style way, often close to wee-fee. You may also hear pronunciations influenced by English.

As a learner, the important thing is that native speakers will understand wifi very easily. You do not need to worry too much as long as your pronunciation is clear.

In Spain, you may also see it written as:

• wifi
• wi-fi

Both are understood.

Yes, especially in Spain, no va is a very common informal alternative.

So these are both natural:

• El wifi no funciona.
• El wifi no va.

The version with funciona is a bit more neutral and explicit.
The version with va is more colloquial and very common in everyday speech in Spain for technology and services:

• La tele no va.
• Internet no va.
• La app no va.

Because in Spanish, the simple present is often used for current situations, especially with verbs like funcionar.

So:

• El wifi no funciona. = The wifi isn’t working.

Spanish does not need a separate form like is not working in order to express that current meaning. The simple present does that very naturally here.

You could also hear:

• El wifi no está funcionando.

But that sounds more like emphasis on the ongoing situation. In everyday use, no funciona is the more normal choice.

Yes. Problema is a masculine noun:

• el problema
• un problema

This is one of a group of Spanish nouns of Greek origin that end in -ma but are masculine:

• el problema
• el sistema
• el tema
• el programa

So un problema técnico is correct, not una problema técnica.

Yes, it sounds perfectly natural and standard in Spain.

It is the kind of sentence you might hear:

• in a hotel
• in a café
• in an office
• in customer service
• in a notice or message

It is clear, neutral, and polite. If you wanted to sound slightly more conversational in Spain, you might also hear:

• El wifi no va por un problema técnico.
• No funciona el wifi por un problema técnico.

But your original sentence is completely normal.