Help Firmware update to stop the DELAY!

[MasterzYuri]

Hey guys,
After a year and half of using windows 8 phones i bought my first android phone ( a Galaxy s3 i9300 - international ).After a few days it started to have delay, i remember i did an update ( the phone came with 4.3 JB ).I only have delay when i try to open contacts / settings / keypad / logs / gallery / camera / power button , 2-3 seconds.
I saw a topic on a forum in which someone said that by updating the phone's firmware to the latest one will solve the delay.
Well since i'm a noob at Android platform i got no ideea how to do it and i have a few questions:
- if i change the firmware version will i lose the warranty?
- are there any risks?
- which is the latest firmware version for the Galaxy s3 i9300? my current firmware version is: I9300XXUGMK6.I did a google search and i found many versions such as I9300XXUGNA8 / I9300xxugnb4 / I9300XXUGML3 / I9300XXUGMK7....
Update Galaxy S3 to I9300XXUGNB5 Android 4.3 Jelly Bean Stock Firmware <-- should i follow this tutorial?

Thanks a lot!

 

[funkylogik]

4.3 is the latest available for the s3 mate. I'm trying to think what you could do to cure the lag (delay) but Samsung are well know for it.
I have a custom rom on mine but I don't think that's something you should mess with yet.
See if there's a minor update available. Go into settings, about phone, check for updates, and see :thumbup:

 

[MasterzYuri]

Yes 4.3 is the latest version but my firmware version is from November 28 - 2013, pretty old. Updating the firmware with a newer version from 2014 might help my phone (i think...).
I checked for updates and it says that i already have the latest updates, might be because of my country ( Romania )...

 

[funkylogik]

Maybe. You can have a look on sammobile.com/firmware and see if there's anything more up to date :thumbup:

 

[nawrokrz]

@MasterzYuri
Today I've updated my GS3 v4.3JB from I9300XXUGMK6 to I9300XXUGNA8. I didn't notice any lags during startup those things you have said. I hadn't any problems when I updated it too. Despite of it previously I've made backup (Samsung Kies 3). Generally, I'm glad

 

[MasterzYuri]

Did you updated it through OTA / Kies or manually ?
Maybe you can provide me a link with the firmware.Thanks

 

[nawrokrz]

I've updated it from OTA, but Kies3 give me the same proposition too.

 

[MasterzYuri]

Through OTA it tells me that there are no new updates, and with Kies "You have the latest firmware version"....i think it depends on each country...