TV Service input

[DuduMil]

Okay, I was plugging something into my TV's AV input, and next to the inputs, I found one that says "Service", and it looks like an AUX input, there's a picture.

What is it for?

 

[Marc_LFD]

That looks like the headphone jack port?

I remember on my oldie LG LCD TV there's "Service," but it was a USB port and meant to update it.

Still, seeing that for some reason reminded me of Hotel TVs and their weird ports you couldn't use. Well, now you can since it's HDTVs (it was an issue with their CRTs).

 

[DuduMil]

The TV has an headphone jack

 

[Elodain]

Probably just wired internally as a USB port and uses a 3.5mm Headphone jack to make it harder for people to use for themselves so you have to rely on their overpriced repair services if something goes wrong with the firmware.

Headphone jacks as USB ports isnt exactly unknown, since the old square iPod Shuffle did that too. Headphone jack doubled as it's USB connection, and it came with the following cable:

 

[DuduMil]

when I looked at this, and judging from where it's positioned, I thought it was for you to hook up one of those ypbpr to AUX, but since I don't have one of those, I can't try it.

 

[Elodain]

when I looked at this, and judging from where it's positioned, I thought it was for you to hook up one of those ypbpr to AUX, but since I don't have one of those, I can't try it

I don't believe so, no. The TV in my living room has a port for that, both Component and Composite, and they are labelled as such. The fact that this is labelled specifically as SERVICE tells me it doesn't have any General use applications.

 

[DuduMil]

Maybe you're right, but I'm going to buy one of these adapters and test it anyway.

 

[Hayato213]

Typically it is an usb port, it allow technician to troubleshoot the tv, as for the 3.5mm cable goes, it is probably 3.5mm audio jack to db9 rs292 for troubleshooting.

 

[Hayato213]

Maybe you're right, but I'm going to buy one of these adapters and test it anyway.

If your tv work, leave it alone

 

[hippy dave]

If your tv work, leave it alone

You've never met a geek before, have you?

 

[FAST6191]

As Elodain and Hayato213 said it is likely something for a technician or failure analysis type to hook up to.

Modern ones are likely to be USB, though some older ones are giant pin connector cards (think CF card but larger, or PCMCIA if you are old like me). 3.5mm or likely quad ring of that size could be USB but more vintage ones might well be JTAG, i2c or something in the http://dangerousprototypes.com/docs/Bus_Pirate / http://dangerousprototypes.com/docs/Open_Bench_Logic_Sniffer world so someone with a custom setup on a test bench somewhere could figure things out when a warranty call came in, and possibly program something if the largely same model but different digital TV encoder was needed to reprogram a bunch of things if a rush order came in from somewhere in the world (say some random Danish or whatever buyer for a shop smokes all the crack and says we will take 30000 when you had expected 5000 for that region you redirect a bunch of your aimed at the US market that you were going to have a hard time getting a bulk purchaser for).

As far as usefulness. If you can figure out what protocol it is then there could be some fun to be had, especially if you can dump (assuming there is no restore/update on a website somewhere) and reflash a firmware with different data or access some kind of settings -- different colours (I once had a glorious widescreen CRT but for some reason best known to itself then 4:3 mode put grey bars down the side rather than black with no way to change in menu), different colour settings, disabling settings you don't want (give me game mode on everything rather than just VGA or something), different ordering/startup, possibly removing protection (macrovision and HDCP being the two most likely). I don't know what I want to link for this sort of thing as as primer as TV hacking is not really much of a thing like this, however they will also behave much like any embedded device so dump memory/firmware and read any strings out you can find to look to as commands, if it is JTAG or something then see what there is by way of default/expected/help commands. If it is proper JTAG then you are probably going to be hard pressed to brick it (though do check to see if there is a nice EEPROM settings chip you can dump and restore) but some of the higher level stuff like USB and serial based stuff is probably going to be more able to brick things.