Mobile Phone & Laptop Audio output - damaged by phantom power 48V

[dicky96]

Hi, I have someone who managed to damage two mobile phones (one samsung galaxy note 3, not sure the other model) and also a HP laptop by connecting the audio out from the headphone/line out jack to the mic inputs of a mixer with 48V phantom power turned on!

Apparently doing this can damage external audio sources especially those devices with unbalanced outputs (exactly like the headphone jack on a phone or laptop)

So all have blown audio/line out. Now I'm guessing this has been done more than once before - so what components are normally damaged? Possibly there is a low powered audio output/amplifier type device on the motherboard?

I'm being asked to estimate the repair cost. Yes I realize the laptop could be used with a USB soundcard and this may be a cheaper option. It seems a bit extreme to condemn the entire motherboard when the devices still function, apart from the line out.

Any advice please?
Richard

[diif]

Re: Mobile Phone & Laptop Audio output - damaged by phantom power 48V

Yes, amp and IC, depends how common they are and how available to you scrap boards/Ali/other online shop. A USB sound card is less than a pound so wins on price.
Any idea on laptop model ?

[dicky96]

Re: Mobile Phone & Laptop Audio output - damaged by phantom power 48V

Gonna find out today when I pick them up. It's an HP that's all I know at the moment

Customer tells me now that both the laptop and the phones are working on internal speakers and the sound cuts out when headphones plugged in. He said they worked for a short while when connected to the mixer, then the sound went off

Which kinda tells me that the audio amp, and for that matter the switching contact in the jack socket, are functioning and maybe there are resistors or caps that connect to the output jack that have failed?

Rich