P1 Carbon Gen 4 about a year old. Thermal paste was nearly solid, and the thermal pads were not placed properly to cover all the components they were meant to. Overheated and crashed tens of times per day since day one. Finally repasted and replaced pads, only to find they literally left plastic covering part of the contact between half the graphics memory and the copper heat sink. They couldn’t even be bothered to design the thermals correctly for a $5500 Core i9 RTX 3080TI laptop.

Massive QC issues in the last 2-3 years at least, while they may not be terrible you definitely have to repaste and re-thermal pad if you get anything Carbon from Lenovo.

I’ve been deploying and servicing Surface Pro’s since the Pro 3, but now that I really think about it, I’ve never actually handled a Pro 4, just everything else in between.

Through all the comments I’ve noticed you don’t appear to have tried the “hard reset” procedure yet? Any time our Surfaces have gotten funky, a hard reset usually kicks them in the butt for a few months until another wonky issue crops up. Your delay to power on sounds just like some of the wonkyness I’ve experienced but moved on from after 15 seconds of button presses. Hold power and volume up for 15 seconds.

I still have my Pro 3, I also have a Pro 5 and Pro 7. My Pro 3 still gets 6.5 hours on the battery, they’re not without their problems but it’s often how you treat them.

I’ve sold and supported hundreds. I’ve only had one come back after someone was unable to follow my instructions above. I was able to perform the above and resold it the next day.