did I fry my ender 3 V2, low voltage after hotend upgrade

ender 3 V2: experiencing low voltage (~6v) at fans and printer not working. im thinking a short circut but i dont know how to diagnose properly.

recently replaced thermistor with a thermocouple (part of my dragon hot end upgrade) and also had to 12V fans running in series off the 24V circuit. was running fine during initial tests then the fans just cut off and started wining a bit. replaced everything to stock and still have the same problem.

tested voltage at fans and it is very low (~6V).

did I fry something?

I would test the Power Supply by disconnecting the Supply leads from the 3D Printer an measure the voltage.

Reconnect and measure the voltage at the Power Supply and the controller if there is a voltage difference you may need the make the Supply leads larger gauge wire.
You can then measure the voltage on the controller while trying to heat the hot-bed or hot-end one at a time, if everything look then heat both an measure again.

Testing can be a long winded process to see if the supply is damaged and cannot supply the full power.

If you cannot get a full 12 or 24Volt with no load connected then the testing is done an the supply may be damaged.
This process means you need to be able to use a volt meter.

Have any questions post.

thank you for the feedback and direction.

24V measured at the fan port with no load, but when I plug the fan in it still does not go and voltage across terminal drops to ~2V. it seems like there is not enough amps getting to the fan port, but everything else looks good.

hot end and bed sill heats up as normal 23.9V measured across terminal. fans work when plugged into an external source.

seems like the psu is not the problem. maybe a bad fan port? could it be a firmware issue?

Replacing the Fans Power Mosfet is a simple process an only requires unsoldering 3 terminals then re-solder.