iBook G3 clamshell turn on but no chime

hi everyone

I just bought an iBook G3 clamshell

graphite firewire model m6411

it's in a very good condition, nothing is broken or so.

but when I turn it on it works but no chime at the beginning and a black screen

here is a video I took of the problem

https://www.youtube.com/watch?v=mdKdAZQO-NI

I've red around in the forums with no lock

I've reset the PMU and it didn't solve it

I've tried it with and without the battery and it didn't solve it

I've replaced the Ram even tho the iBook dose not make any "beeps" at start but still no luck

any idea what might be the problem and is there anything to try doing?

thanks!