Why is my Tab S stuck on the boot screen and not going to recovery mode?

A

AC Question

why is my tab s stuck on boot screen and not going to recovery mode

So i have the galaxy tab s 10.5 inch sm-t805
Iv had it before the lollipop update was release so it was working fine until it updated to 5.0.2 lollipop
After updating it the wifi toggle just wont switch on.. no matter how many times i restarted it.. i even reseted it n it still wont work.
So i decided to downgrade it by odin to 4.4.2
After i did so the device wont turn on
It would only show me the boot screen which says samsung tab s and then just goes black.. after it going black by a few mins it says "samsung" as if it is going to start again but it doesnt start.. it stays that way for more than 10 mins.
I tried going into recovery mode but it just wont go. I held the buttons required for over a minute n it wont go there. It doesnt even switch off.. like at all. I can only get it to go to download mode.
I need help with this so please if u have any idea whats wrong and how to fix it id be very very greatful.
Thanks in advance.