you look for problems, will get problems. just enjoy it and don't be quick to blame it for every problem you encounter. Sometimes can be fault of network, sim card etc.

Anyway, all the basic maintenance to phone and memory card applies . Soft-reset/hard reset the phone if you are encountering problems which is not solvable by other means.

For the basic thing can refer to FP. Most of the common problem is stated at there.

anyone tried install wefi? How come i see a lot of square square letter? unsupported language?

Can't give you confirmation on that. I only use the default option to look for connection   

I don't get what u mean. So now can u start up your phone like normal?

After 30 minutes to merge calibri bold font and 5800 default font... I succeeded!!!
Here's the nice outcome:






Any comments? Can type chinese + cute calibri english font

How's watching erm..S9 on tube?   
Satisfying eh? 

The black screen then rainbow color then fade into right side then auto reboot thing all CONFIRMED is software related and not the hardware problem, i can do a demo to simulate the effect again and again on the same corrupted software after the do a disk scan.

It's quite troublesome as the removable mem seem easily been screwed up and once something corrupted if u lucky it can be resolve by reinstall the affected apps but if u like me un-lucky then everytime try to reinstall those corrupted apps it just turn the screen to rainbow then reboot.