IMAC A1418 no internal audio

[reset1986]

hi, i have this imac that does not emit sound from the internal speakers, when i turn it on i hear the boing, but once in the system it has no audio from the internal speakers,
with headphones you can hear it, in the settings there is always the digital output active, or when i insert the headphones it changes headphones,
i disconnected the headphone jack plate on the motherboard but it does not solve the situation, do i have to replace it? ic audio?

[mon2]

Blow out the headphone connector with compressed air. There may be some junk inside.

[reset1986]

Blow out the headphone connector with compressed air. There may be some junk inside.

thanks, already tried with isopro alcohol. blown with air etc, nothing, from what I read there is a contact in the connector that without the jack inserted must be closed to enable the internal speakers, if open the digital output with the red light remains active, I was thinking of bridging these two contacts, do you know which ones are on the connector?