MacBook Pro 9,2 Bricked

Done upgrades many a time with OCLP, but sadly looks like I bricked a MacBook Pro 9,2 by building an install package for MacBook Pro 10,2 by mistake.

It all looked good and running, except the battery indicated a failure, then it eventually powered off even when on charge, and the SIL light pulsed when I could get it to start.

Immediately if I was lucky, after the startup tone, it would just go into a boot loop, with a second of the tone; the SIL light would pulse about 4 times and then try to reboot.

I’ve had the battery out, I’ve done a PRC and SMC reset, I’ve replaced the battery which doesn’t charge still. I’ve erased the boot disk, but cannot even boot from USB.

I managed randomly to get it stable, and did get to reinstall part of Ventura for 9,2 on it, before it started rebooting again.

I am beginning to wonder if the 10,2 fritzed the firmware for the power/battery charger.

I know the internal fan powers on, but think I’ve ran out of options with memory swapped and battery swapped.

Could it be the charger and this is coincidence?

Can you accidentally update firmware by installing the wrong install kexts in Ventura?