Hello I had a similar issue. My ps4 which was purchased in 2018 making it 4 years old at time of failure. Ps4 slim sae-003 mother board. Was full of dust fan was very loud. One day it just cut out while my son was playing just one beep and powered off. Couldn’t get it to power back up but no 3 beep warning for overheating. I cleaned the entire unit re-applied new thermal paste re-assembled with new power supply because the old one wasn’t showing 12v got the unit to turn on opened up a game and got about 10 mins in when it powered down unexpectedly again. Read online to flip it over as a test for broken solder balls and it stayed running for about 1 hour before powering down the same way again . Used thermal imager and found the ic ram chips were all around 168*F. But everything heated up evenly. I also noticed the fan only runs at low speed. Just wondering if I have a fan issue that’s causing it to power down or does it sound more like a solder ball failure. System was never dropped or anything like that but my son turn power save settings off so it ran constantly day and night for a few months.