Razer Blade 15 Advanced (2020 model) power cycling several times on boot?

Folks, Been having some issues with a 2020 model Blade 15 Advance (RZ09-0330xx series) recently. I'm hoping someone has some idea or experience with similar symptoms. Didn't see anything searching / trawling the forum, but could totally be missing something. Basically, on power on it's power cycling repeatedly, several to half a dozen times or so, before finally staying on. It seems to begin the very beginning of the boot process each time, but never gets as far as the OS before bouncing again. I took off the back panel, nothing obvious there, no bulging battery etc. I'm suspecting power supply or motherboard..? Anyone either have a similar experience or know what this is indicative of? Trying to figure out if the machine's dying or not...