I've exhausted all my other options so I'm turning to the community for suggestions on this one!

Alienware m15 R3 purchased 2020. Within first year, CPU fan died and needed replacement, then motherboard needed replacement due to failure. I ended up extending the warranty once or twice to try and protect my investment since I'd never had so many issues with a laptop before. In the 2nd year, the side board was replaced twice. Smooth sailing after that for about 6 months, so I did not pay to extend again (last warranty expired 12/29/22).

Fast forward to 3 weeks ago, playing a game like usual, laptop suddenly powers off, no error codes/noises/screens. Will not power back on regardless of outlet used. Next morning, laptop magically works again no issue. Several days later I get an error regarding AC adapter not supported or something (it's the original OEM ac adapter the laptop came with). Ignore error and laptop works for another few days. Then while gaming, I get keyboard flashing red, and Alienware logo flashes red 3x and then blue 1x, then powers off, will not power back on. Next couple of days, the magic from before is gone, never powers back on. I read the code is due to CMOS battery issue, but since I've never had to replace one of those before, I thought it's much more likely to be battery/charger related. So I purchased a brand new OEM battery, and OEM AC adapter to be safe, installed, no luck. Computer will still not turn on at all. Notes:

• AC Adapter has blue ring, so power is going to it correctly
• Made sure to drain flea power between battery swap.
• Tried unplugging battery, and running directly off AC, no luck.
• Tried using USB-C charger, no luck.
• I've also tried old battery + new charger, no luck.

Is it possible that a bad CMOS battery would cause this? Dell wants to charge and arm and a leg to diagnose this, and I don't want to give them another dime since I'm already in thousands between the laptop + extended warranties. My next thought is replacing the CMOS battery and maybe the battery cable, but I'm not sure how either of those would affect the 3rd bullet point not powering on. Any insight or suggestions appreciated!