I disassembled again. Fully cleaned the motherboard, it was a bit dusty. I didn't find any evidence of liquid damage. Made no difference.
5v rail reads at 5.3v-5.6v before fan kicks on. It reads a steady 5v once fan kicks on.
Google "LA-8133P", that seems to be the schematic for it. Looks like the fan is driven directly off the +5VS rail and has tach/PWM signals connected to the EC. You can try disconnecting the PWM/tach (probably will cause fan to run at full speed) and see if that works... it could be a corrupted EC firmware.
I disconnected the PWM and tach. Laptop booted right up with fan on high but of course got fan error.
I downgraded the bios to older version and it will now boot on every second attempt with only battery. Before it would only do this with adapter plugged in.
So, that is where I am at. Will always boot on second manual attempt, will run all day long with no problems. Will boot fine on a restart as well. It just will not boot up on first attempt.
Any other ideas?
Thanks again.