Question Toshiba S55-B5280 doesn't start

[Billsey]

Lights all seem normal, fan spins up then shuts down. It's getting far enough that it takes a long press of the power button to shut back down. I get the same symptoms if I remove the HDD and memory so it looks like there's no POST. I've tried doing a battery reset and booting with battery removed. There doesn't seem to be a CMOS coin cell on this model so I can't try a CMOS reset. Is there anything else I can try?

 

[Billsey]

So, no suggestions? Should I give it try to find a used motherboard?