FAT32 max filesize is 4Gb.

Note 2 thread, post 3, under The Micro SD Card.

Are you testing the phone without any other Apps installed for these couple of days?

Or you already started to put in your favourite Apps?

This is important as to find out if any Apps (even if running in background) causing the issue. If there are other Apps, we can't tell for sure if it is problem with the firmware or other Apps.

See a few post above you (this same page) and you'll know a few new things.
#1050 - can root by flashing Adam kernel.

#1059 - how and which kernel support exFat and NTFS

Sighh..

Upon resetting my phone, I only installed Whatsapp to determine if certain apps were the cause of the random reboot. But when I tried using my camera, it froze and rebooted.

It was then that I sent my phone to the service centre and they reinstalled the entire software. After that, the frequency of the random reboot lessen even with all my funky apps installed.

Yesterday, send to Celcom. They reset/format the phone but still same problem. They replace with new simcard but same problem cannot send sms. We decided try with other no but celcom simcard still same, try with other telco simcard, success can send sms. Conclusion my S4 cannot use Celcom simcard.

They don't replace with other phone but asked me to go to Samsung center to check. At Samsung they reformat/reset the phone again. After one & half hour, they call me to collect the phone. Put back my Celcom simcard still same problem, they try with other celcom simcard still same. At last I asked them put other telco simcard & success. But they also no replacement provide but asked me to go back to Celcom Bukit Rajah for replacement or go Samsung Summit for another check coz the said Samsung Klang no replacement procedure. I go back to Celcom branch Bukit Rajah but the office closed.

Now, 

Hi which samsung service center you have sent your S4 for reinstall the software?

Any center can do that
You can even do yourself using odin in pc
Download the rom from www.sammobile.com/firmware

Hi which samsung service center you have sent your S4 for reinstall the software?

What is the rom for our i9500?

I sent mine to Samsung @ Gardens (KL) as they have a technician there for software related purposes. But you can choose to directly go to the service centre in PJ (near the Federal Highway) or the one located at Pandan Capital Shopping Complex if you're from KL. I heard the service centre in lowyat is closed due to renovations.

The re-installation of the software took about 1 hr 30 mins to 2 hrs to complete.

may i know do i need to bring my box over? becos everything i put at my hometown

may i know do i need to bring my box over? becos everything i put at my hometown

Nope, I just brought my phone there, even forgot to bring my receipt 
So should be fine for you 

Unless you're going to bring it to the designated service centre, then I'm not so sure haha

u mean u bought to the place u bought the phone? or u bring to any service centre?

Just brings your phone only to any Samsung authorized service center.. don't go to other service center like Proton or Perodua ... should I add more

I sent mine to Samsung @ Gardens (KL) as they have a technician there for software related purposes. But you can choose to directly go to the service centre in PJ (near the Federal Highway) or the one located at Pandan Capital Shopping Complex if you're from KL. I heard the service centre in lowyat is closed due to renovations.

The re-installation of the software took about 1 hr 30 mins to 2 hrs to complete.

lolz ok.. damn no sc in shah alam.. have to bring to digital mall nearest.. digital mall tat one can service? or must go gardens one better?

lolz ok.. damn no sc in shah alam.. have to bring to digital mall nearest.. digital mall tat one can service? or must go gardens one better?