I am thinking about buying a new G3, Is there any chronical issues-problems of LG G3?
Like dust in screen or speaker blow or any hardware malfunction
Like dust in screen or speaker blow or any hardware malfunction

I have not encountered ANY of these issues, except for the heat issue.. But seriously it doesn't get that hot? Mine gets to about 55 degrees Celcius and that's max.. (I have the int. Version though)Don't be completly discouraged when reading this, as this is just my list of CONs for this phone.
Here's some of the issues i've had on my G3 from the very minute my phone left the box:
1. The phone has a locked bootloader, So don't expect any custom roms or kernels anytime soon.
2. This phone gets very hot for almost no explainable reason all the time doing small tasks like browsing the web.
3. WiFi (and maby LTE??) are REALLY slow in comparison to every other phone i've owned in recent years (sometimes web pages even freeze while loading).
4. The stock web browser kills my battery in about 2-3 hours from a full charge on 0% brightness because of LGs stock webbrowser sandbox security.
5. I get constant "connection timed out" errors while trying to stream many online videos using the stock web browser.
6. CPU doesn't hit max speed on this device without messing with thermal options.
7. The phone is very laggy & slow on my version (10b), I don't know how other versions are though.
8. The glass started falling out of my first G3 (around the edges) and i had to exchange for a new one because of this. (my new one did this too but only at the bottom and i just live with it)
9. VERY poor color & contrast when the screen brightness is turned way up (looks good at low brightness though).
10. My left headphone buzzes while the CPU is under load while no audio is playing, Once the CPU load stops or once a song or movie starts playing the buzzing stops (tested with 2 sets of headphones, both buzz but apparently some other users say there are headphones that don't do this).
11. + some other small things.
Probly the most complained about things are these:
1. lag
2. overheating
3. physical cracks develop usually around the ir blaster or mic