Not booting, fans coming on.

Hi Everyone

After mysuccess getting my mbp back running I thought I’d try the other machine in my Apple graveyard. This is an 13” Air, late 2015.

History - It did suffer liquid damage and I replaced the backlight fuse to get it up and running again a year or so ago.

Now when it is started, the fans start, a USB mouse will light up, the CPU & SSD get warm but no chime and nothing shows on bulit in/external screen.

Can anyone suggest a few places to start, points to check voltages etc I just havent a clue where to start?

cheers.