Resolved Mac mini with no sign of life

[tripleintegral]

Hi everyone,
I have a 2006 Mac mini A1176 which refuses to turn on. when I click on power button, nothing happens: no fan, no beep, no song, it doesn"t show any sign of life.
What should I verify first ? I opened it and found nothing suspect, maybe the CPU died ?
The power brick seems to work fine on my other mac mini.
Thank you.

 

[Fishrrman]

Does the motherboard have a PRAM battery?
Has it ever been changed?

 

[tripleintegral]

It have a 2032 coin battery, i changed it a long time ago.
I tried to boot without it, but nothing changes, still the same issue

 

[Partron22]

Nevermind, you checked it.

 

[tripleintegral]

I changed it, tried to reset SMC by all possible ways, replaced the CPU but nothing.
I suspect some issue in the logic board, maybe it's completely dead.

 

[tripleintegral]

I took the machine to a repair store, it's apparently dead.
He tired to track defect components, reflow GPU/chipset, but nothing (and I paid nothing too!)
Thank you for your help anyway.