a500+ repair help needed

[chsedge]

I got today an old a500+ not working.

I tried at home with a power supply of mine and a 520unit to get the video signal out of the rf connector.

I powered it on and get nothing, only black screen. I tried to swap something from another a500 like the 68000 and the fat agnus but nothing again. Drive doesn't click or search for anything. The green led remain stable even after the power on.

Have you any suggestions? What should I check in first place?

The power supply and drive are perfectly working from another a500.

thanks

[chsedge]

I tried also that but I also get a black screen. Also tried to replace denise chip. I think it's the video ic as you told. But explain me this, if this is broken the boot process can't get finished? that is why the floppy doesn't click?

excuse me for my bad english, I'd like to know if this causes to the amiga to stop before doing the initial check of the hardware

And also another question, is this video hybrid done by resistors only, can I replace it with some of them? Is there any circuit or data available?

bye