Help recover my dead player CellTech

[HeyLe]

Hello everybody!
I had mp4 player CellTech model CT91. I bought it in Malaysya in 2007. Here is the photo of my player





It looks similar as this player

Vortex VMP44096-05

But mine is 1GB.

It worked fine about 1 year and then it stoped to start. It takes the charge - when I charge it the flashing lamp change its color from red to blue as writen in manual. When I push and hold the on/off button the flashing lamp lights blue as must be when the player is loading. But nothing is happend - the player cannot load and cannot start - the screen stay black. The computer cannot see it too when I connect it to my PC.
Please, anybody can help me what is the problem with my player and what I must to do to repair it.
Also I didn't upgrade its firmware and unfortunately I have no any backup

Thank you for looking
And waiting for help from anybody

Thanks