Blackberry Bold 9700 not tuning on

I found my blackberry bold 9700 from a long time ago and i tried charging it overnight but it didnt turn on, i also tried the videos on youtube to bring you blackberry back to live but that didnt work i think, i saw a battery screen and after that a sort of blackberry startup screen but then it died again. I tried the youtube video things again and it isnt working anymore. I only see a red light and its on for like 30 seconds and then goes off for 15 second’s and after those 15 seconds the red light goes on again. Anyone that can help??