PS3 Slim 2000x Turning Off When Playing Games [Recently Deep Cleaned]

Hi.

I recently deep cleaned a PS3 Slim Model: 2001A for my sister. I used a light brush & cotton swab + IPA to clean up all components from the fan, heatsink, motherboard, Inside the PSU, and Inside the BluRay Drive aswell.

I also applied new thermal paste after cleaning up the old one and replaced all the thermal pads [I used 1.5mm] (Including the 2 found inside the BluRay Drive). I also replaced the old CMOS battery with a new one. I also ran the system with the upper shell open to see that the fan was running properly which it was.

Now the problem is, whenever she tries to play a game (she tried multiple games), the PS3 shuts down after a couple minutes and makes that BEEP BEEP BEEP sound during turnoff. She said when she left the system idle or if she watched netflix on it, it would just run as usual. She did say it would run hot but i cant be sure since i know 2000x models generally run hotter than the others to begin with.

Earlier i assumed that the issue was in the BluRay Drive because i may have used thicker thermal pads inside it but recently the PS3 showed blinking red light upon turnoff so i think the issue is overheating. I just dont know what is causing it.

But i wanted to know if anyone has experienced any issues like this before? It was running perfectly fine before and when i turned it on after doing the maintenance, everything was functioning as it should, i just didnt stress test much with games sadly. So this issue definately has to do with something wrong that has happened after the maintenance that i did.