Defectul este pe ecran.

In Romanian, the definite article is usually attached to the end of the noun, not written as a separate word like English the.

• defect = defect / a defect
• defectul = the defect

So -ul here is the masculine/neuter singular definite article.

Defect is a neuter noun in Romanian.

Neuter nouns behave:

• like masculine in the singular
• like feminine in the plural

That is why in the singular definite form you get defectul, with the same article ending you often see on masculine singular nouns.

Este is the verb to be in the 3rd person singular: is.

In this sentence, it links the subject and the location:

• Defectul = the defect
• este = is
• pe ecran = on the screen

So the full sentence needs este in normal standard Romanian.

In casual speech, many speakers often shorten este to e:

• Defectul e pe ecran.

That is very common and natural.

Here pe is the preposition meaning on.

So:

• pe masă = on the table
• pe perete = on the wall
• pe ecran = on the screen

This is just the normal prepositional use of pe.

No, not in this sentence.

Romanian also uses pe in another grammar pattern, especially before certain animate or specific direct objects, for example:

• Văd pe Maria. = I see Maria.

But in Defectul este pe ecran, pe is not marking a direct object. It simply means on.

Romanian often uses an unarticulated noun after a preposition when the meaning is general or idiomatic.

So pe ecran can naturally mean on the screen / on-screen.

If you want to specify a particular screen, Romanian often uses a more specific form, for example:

• pe ecranul telefonului = on the phone’s screen
• pe ecranul principal = on the main screen

So pe ecran is perfectly natural when the screen is understood from context.

Defectul este pe ecran is the normal, neutral word order.

Romanian word order is fairly flexible, but changing it usually changes the emphasis.

For example:

• Defectul este pe ecran. = neutral statement
• Pe ecran este defectul. = more marked; it emphasizes the location and sounds less neutral in everyday use

So the original order is the most natural default.

A simple learner-friendly pronunciation guide would be:

de-FEK-tool ES-te pe e-KRAN

A few notes:

• c in defectul sounds like k
• ecran starts with eh-
• the stress is roughly on -fect- in defectul and on the second syllable in ecran

If you want a more natural spoken version, many speakers would say:

• Defectul e pe ecran.

Put nu before the verb:

• Defectul nu este pe ecran. = The defect is not on the screen.

In everyday speech:

• Defectul nu e pe ecran.

In Romanian, a yes/no question is often made just by intonation:

• Defectul este pe ecran?
• more commonly in speech: Defectul e pe ecran?

Romanian does not usually need a separate helping verb like English is at the beginning. Intonation does the job.