Meteor 65/75 issue

I have a Meteor 65 and 75 with SPI ELRS. This happened to both within a couple of months, wondering if anyone knows what is going on?

• I was flying around normally having fun
• I stopped to change batteries
• Put the new battery in and it only does the first 3 beeps
• There is no signal on the goggles
• Plug the flight controller into Betaflight and the VTX (I think) starts smoking

The first time this happened, I cleaned everything up and it started working again but with very poor VTX signal. So I replaced the VTX and shortly after the accelerometer or gyro went out forcing me to replace the flight controller.

Now this just happened again on a different Meteor and before I go through the same steps as last time I'm wondering if anyone has some advice. Thanks.