Mine is 505 so anyway to check to see if the board has been changed out?
Hi, is any way to check serial number and hardware version on the g4?
There is a great app on Google Play called
LG Phone Info - screen shots look like it is in Vietnamese or something, but it is actually in English and is great for finding your motherboard's serial and also great for finding the country code of your phone (listed as "Provider") - the country code will tell you if the phone can be bootloader unlocked (if it is an H815) as shown in
this famous post of mine from last December.
An alternative and equivalent app to LG Phone Info is
LG Phone From
Speaking of bootloader unlockable LG G4 which are quite hard to find in USA, and work great on AT&T,
this ebay seller in UK has 10 unlockable bootloader H815 phones, brand new in sealed LG box, Euro country code ROM (Romania)! - at a very low price of around US$345 shipped, I just ordered one for my GF, as bootloader unlockable ones you cannot find at this price, if you can find them at all. - I expect these will go quickly once word gets around.
Bootloader unlocked has another side benefit from the normal advantages like no advertising with AdAway, rooting in MM, etc. - it also allows you to delete any bloatware or problem files from your phone, and allows you to optimize the phone and get it running crazy cool temps, then you have very long battery life, and best of all, NO BOOTLOOPS - I have been using a "505" H815 model for 16 months this way, and it will never bootloop, it runs so cool you would think it is not even powered on!