Samsung galaxy tab 10.1 won't turn on but flashing camera flash when power button pushed long

[botchag]

When my samsung galaxy tab 10.1 (p7500) tab shut down I tried to open it by pressing the power button a couple of times, it turned on after several tries. I really had a hard time turning it on. Then after a week or so with this problem my battery icon showed a red x symbol. It disappears when I unplug-plug-unplug-plug the charger to the tab. It charges very slowly. Suddenly when I brought it to work fully charged, I tried to open it bu it was turned off and won't turn on. I have been trying to do all button pressing combinations but to no avail. When I plugged it in and tried to long press the power button, the camera flash would blink, but it stopped for awhile. What seems to be wrong? How can I solve this? Battery? motherboard? Thanks. I really need to solve this fast because I use it for my work.:'(